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To: cs551@merlot.usc.edu
Subject: Re: cs551: project 2
Date: Tue, 05 Sep 2006 20:26:55 -0700
From: william@bourbon.usc.edu
Someone wrote:
> On the Possion cdf, how refined do u want the cdf, i.e the number of
> buckets.. like in the lecture it was 5
Since you have equation for F^{-1} (inverse of F), you
should just use the equation. So, infinite number of
buckets.
--
Bill Cheng // bill.cheng@usc.edu
william@bourbon.usc.edu wrote:
> Someone wrote:
>
> > I wanted to clarify the inter arrival time concept.
> > q1) would we will use the GetInterval() func to calculate the time
> > customers arrival into the queue and the service time?
>
> For arrivals, you should call GetInterval() to get *inter-arrival times*.
> For service, you should call GetInterval() to get *service times*.
>
> > q2) u said to call these function is after the parsing. but wudnt u have
> > to call getInterval every time u have u get the arrival interval and the
> > service time for each customer. ?
>
> Yes. What I mentioned during class is about how much to sleep
> for your thread. If GetInterval() returns, say, 1625ms for
> an inter-arrival time, and it has been 500ms since the last
> arrival, you should sleep for 1125ms and *not* 1625ms.
>
> > q3) in the ExponentialInterval(), do we use the possion distribution to
> > calculate the time. combined with method you showed us in class last week?
>
> Yes. Please remember that inter-arrival times for a Poisson
> Process is distributed according to an exponential distribution
> with the same mean.
>
> > q4) about the book keeping. how do we estimate this time required for
> > book keeping ? is it some constant or do we calculate it using real
> > timestamps of the system?
>
> You should use the actual timestamps of the system. You are
> not suppose to model nunki.usc.edu.
> --
> Bill Cheng // bill.cheng@usc.edu