In this paper we survey recent results on the precedence constraint single machine scheduling problem to minimize the weighted sum of completion times. We show how we can benefit from known results in dimension theory of partial orders to obtain improved approximate solutions when precedence constraints have low fractional dimension. We believe that dimension theory of partial orders could be o...

One of the most recent techniques for propagating resource constraints in Constraint Based scheduling is Energy Constraint. This technique focuses in precedence based scheduling, where precedence relations are taken into account rather than the absolute position of activities. Although, this particular technique proved to be efficient on discrete unary resources, it provides only loose bounds f...

Comet is an object-oriented language supporting a constraintbased architecture for local search. This paper presents a collection of abstractions, inspired by constraint-based schedulers, to simplify scheduling algorithms by local search in Comet. The main innovation is the computational model underlying the abstractions. Its core is a precedence graph which incrementally maintains a candidate ...

Research in assembly planning can be categorised into three types of approach: graph-based, knowledgebased and artificial intelligence approaches. The main drawbacks of the above approaches are as follows: the first is time-consuming; in the second approach it is difficult to find the optimal solution; and the third approach requires a high computing efficiency. To tackle these problems, this s...

We consider the single machine scheduling problem to minimize the average weighted completion time under precedence constrains. Improving on the various 2-approximation algorithms is considered one of the ten most prominent open problems in scheduling theory. Recently, research has focused on special cases of the problem, mostly by restricting the set of precedence constraints to special classe...

Title of dissertation: DATA-AWARE SCHEDULING IN DATACENTERS Manish Purohit, Doctor of Philosophy, 2016 Dissertation directed by: Professor Samir Khuller Department of Computer Science Datacenters have emerged as the dominant form of computing infrastructure over the last two decades. The tremendous increase in the requirements of data analysis has led to a proportional increase in power consump...

A soft global constraint SOFTPREC has been proposed recently for solving optimisation problems involving precedence relations. In this paper we present new pruning rules for this global constraint. We introduce a pruning rule that improves propagation from the objective variable to the decision variables, which is believed to be harder to achieve. We further introduce a pruning rule based on li...

The parameterized computational complexity of a collection of well-known problems including: Bandwidth, Precedence constrained k-processor scheduling, Longest Common Subsequence, DNA physical mapping (or Intervalizing colored graphs), Perfect phylogeny (or Triangulating colored graphs), Colored cutwidth, and Feasible register assignment is explored. It is shown that these problems are hard for ...

It is shown that the Precedence Constrained K-Processor Scheduling problem is W [2]-hard. This means that there does not exist a constant c, such that for all xed K, the Precedence Constrained K-Processor Scheduling problem can be solved in O(nc) time, unless an unlikely collapse occurs in the parameterized complexity hierarchy introduced by Downey and Fellows (see [5]). That is, if the problem...

It is shown that the Precedence Constrained K-Processor Scheduling problem is W2]-hard. This means that there does not exist a constant c, such that for all xed K, the Precedence Constrained K-Processor Scheduling problem can be solved in O(n c) time, unless an unlikely collapse occurs in the parameter-ized complexity hierarchy introduced by Downey and Fellows (see 5]). That is, if the problem ...