Mordechai Shalom

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We consider a scheduling problem in which a bounded number of jobs can be processed simultaneously by a single machine. The input is a set of n jobs J = &#x007B;J<inf>1</inf>, &#x2026; , J<inf>n</inf>&#x007D;. Each job, J<inf>j</inf>, is associated with an interval [s<inf>j</inf>, c<inf>j</inf>] along which it should be processed. Also given is the(More)
We consider the following online scheduling problem in which the input consists of n jobs to be scheduled on identical machines of bounded capacity g (the maximum number of jobs that can be processed simultaneously on a single machine). Each job is associated with a release time and a completion time between which it is supposed to be processed. When a job(More)
All-optical networks have been largely investigated due to their high data transmission rates. The key to the high speeds in alloptical networks is to maintain the signal in optical form, to avoid the overhead of conversion to and from electrical form at the intermediate nodes. In the traditional WDM technology the spectrum of light that can be transmitted(More)
The problem of grooming is central in studies of optical networks. In graph-theoretic terms, this can be viewed as assigning colors to the lightpaths so that at most g of them (g being the grooming factor) can share one edge. The cost of a coloring is the number of optical switches (ADMs); each lightpath uses two ADM’s, one at each endpoint, and in case g(More)
The placement of regenerators in optical networks has become an active area of research during the last few years. Given a set of lightpaths in a network <i>G</i> and a positive integer <i>d</i>, regenerators must be placed in such a way that in any lightpath there are no more than <i>d</i> hops without meeting a regenerator. The cost function we consider(More)
Minimizing the number of electronic switches in optical networks is a main research topic in recent studies. In such networks we assign colors to a given set of lightpaths. Thus the lightpaths are partitioned into cycles and paths, and the switching cost is minimized when the number of paths is minimized. The problem of minimizing the switching cost is(More)
SONET add/drop multiplexers (ADMs) are dominant cost factors in WDM SONET rings. Whereas most previous papers on the topic concentrated on the number of wavelengths assigned to a given set of lightpaths, more recent papers argue that the number of ADMs is a more realistic cost measure. Some of these works discuss various heuristic algorithms for this(More)