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vidi:track1 [Monday, 16 March 2009 : 11:49:21]
lefeber
vidi:track1 [Monday, 16 March 2009 : 12:33:46] (current)
lefeber
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 +======Research proposal======
 +=====Plan of work=====
 +====Research plan====
 +===Track 1: Central control===
 +This track, to be performed by the applicant, is concerned with state feedback
 +control of general deterministic networks
 +and builds on the applicants first results ​ ([#​References|references]).
 +
 +The approach as introduced in  ([#​References|references]) seems to be applicable to
 +arbitrary switching networks with setup times, for arbitrary given feasible
 +network behaviors, while taking into account buffer constraints. However, only
 +convergence towards behavior similar to that of the desired periodic orbit can
 +be guaranteed. That is, it might be that some buffers always contain a fixed
 +number of additional jobs, compared to the desired periodic orbit.
 +Therefore, first the approach as introduced in  ([#​References|references]) should be modified to
 +overcome the above mentioned shortcomings. This will be joint work with the group of
 +prof. Leonov (St. Petersburg University, Russia).
 +
 +Jobs moving from one server to the next often involve a non-negligible
 +transportation delay. As a next step, the approach can be extended
 +to networks with transportation delays between servers. This will be joint
 +work with the group of prof. Helbing (TU Dresden, Germany), including applications to traffic light control.
 +
 +Furthermore,​ the current approach leads to only one possible feedback. In
 +practice this is undesirable. A class of feedbacks needs to be derived
 +and depending on desired transient performance an appropriate
 +feedback needs to be selected from this class. Typically, controllers have gains which can be used
 +for tuning performance. Another constraint on the controller design
 +might be the time between two successive series of service of a job type.
 +The next step is to extend the approach to
 +accommodate for tuning. This will be joint work with dr. Robertson (LTH Lund, Sweden),
 +including application to the control of internet servers.
 +
 +Related to this is the problem of deriving optimal network behavior. Since of all
 +possible feasible desired behaviors, optimal network behavior is the most interesting one to
 +make the system converge to. This issue will be addressed with the Combinatorial Optimization
 +group of prof. Woeginger (Mathematics and Computer Science, TU/e), in particular with dr. Hurkens
 +and dr. Sitters.
 +
 +When considering buffer constraints,​ not only the desired behavior plays
 +a role. Buffer constraints can make it impossible to reach
 +the desired behavior from the current state, as illustrated in  ([#​References|references]).
 +This reachability question is the next question to address.
 +
 +Finally, the influence of different parameters is studied.
 +What happens if parameters are different than assumed during controller design?
 +So what if some arrival rates, processing rates, setup times, and/or transportation delays are
 +different? What happens for time varying arrival rates?
 +Under what conditions does
 +the proposed feedback still yield reasonably good results?
  
vidi/track1.txt · Last modified: Monday, 16 March 2009 : 12:33:46 by lefeber