@mastersthesis{
    Vrp91,
    author = "Varpaaniemi, Kimmo",
    ps = "modsim.ps",
    school = "Department of Computer Science, Helsinki University of Technology",
    title = {{U}{N}{I}{X}-ymp{\"{a}}rist{\"{o}}ss{\"{a}} toimivan ohjelmistoliit{\"{a}}nn{\"{a}}n suunnittelu ja verkkoteoreettinen analysointi ({D}esign and Net Theoretical Analysis of a Program Interconnection in the {U}{N}{I}{X} Environment)},
    abstract = "Design and net theoretical analysis of a program interconnection in UNIX environment are presented. The interconnection is between Modest, an estimation program, and Simnon, a simulation program. Simnon serves Modest. One aim of the design of the interconnection is to get Modest to take the best possible advantage of Simnon. Another aim is to give a chance for the users of Modest to write their models in the high level language of Simnon. The interconnection supports modular modelling and extends the selection of models of Modest. \par The interconnection is based on UNIX interprocess communication. The source files of Simnon are commercially protected amd therefore have not been modified. UNIX domain stream sockets are used for interprocess communication. An external Simnon system writes simulation results in binary form to a socket. Modest performs an interpolation based on those simulation results. Due to the solutions mentioned the interconnection between Modest and Simnon is as efficient as possible considering the restriction that the source files of Simnon are not allowed to be modified. It has been demonstrated experimentally that the duration of a Modest run is, independently of input, as long when using UNIX domain stream sockets as when using named pipes or using message queues together with UNIX domain stream sockets. \par Communication events of the interconnection have been analysed using P/T-nets. Two central communication phases have been modelled, each by its own P/T-net. Using S-invariant analysis, T-invariant analysis and reachability analysis it has been shown that the modelled parts of the interconnection always work as they should.",
    address = "Espoo, Finland",
    month = "June",
    flags = "public,copy",
    year = "1991",
    keywords = "estimation, simulation, interprocess communication, P/T-nets",
    pdf = "modsim.pdf",
    type = "{M}aster's thesis"
}