The relative worst order ratio is a measure for the quality of online algorithms. Unlike the competitive ratio, it compares algorithms directly without involving an optimal offline algorithm. The measure has been successfully applied to problems like paging and bin packing. In this paper, we apply it to machine scheduling. We show that for preemptive scheduling, the measure separates multiple p...

Fixed-Priority Scheduling with Deferred Preemption (FPDS) is a middle ground between Fixed-Priority Preemptive Scheduling and Fixed-Priority Non-preemptive Scheduling, and offers advantages with respect to context switch overhead and resource access control. In this paper we present our work on extending the realtime operating system RTAI/Linux with support for FPDS. We give an overview of poss...

Fixed-Priority Scheduling with Deferred Preemption (FPDS) is a middle ground between Fixed-Priority Preemptive Scheduling and Fixed-Priority Non-preemptive Scheduling, and offers advantages with respect to context switch overhead and resource access control. In this paper we present our work on extending the realtime operating system RTAI/Linux with support for FPDS. We give an overview of poss...

It is with the aim of solving scheduling problems with irregular cost functions that this paper focuses on the continuous assignment problem. It consists in partitioning a region of R into subregions of prescribed volumes so that the total cost is minimized. The dual problem of the continuous assignment problem is an unconstrained maximisation of a non-smooth concave function. The preemptive va...

Problem statement: One of the Cloud Services, Infrastructure as a Service (IaaS) provides a Compute resourses for demand in various applications like Parallel Data processing. The computer resources offered in the cloud are extremely dynamic and probably heterogeneous. Nephele is the first data processing framework to explicitly exploit the dynamic resource allocation offered by today’s IaaS cl...

We study the classical problem of scheduling a set of independent jobs with release dates on a single machine. There exists a huge literature on the preemptive version of the problem, where the jobs can be interrupted at any moment. However, we focus here on the non-preemptive case, which is harder, but more relevant in practice. For instance, the jobs submitted to actual high performance platf...

The CPU scheduling is one of the most important tasks of the operating system. Many algorithms are designed and used in this regard each having advantages and disadvantages. In this paper a new algorithm for the CPU scheduling is presented using FFGA (Fonseca and Fleming’s Genetic Algorithm) multiobjective optimization. Contrary to the classical algorithms in use, it uses the three parameters o...

We investigate the problem of scheduling the maintenance of edges in a network, motivated by the goal of minimizing outages in transportation or telecommunication networks. We focus on maintaining connectivity between two nodes over time; for the special case of path networks, this is related to the problem of minimizing the busy time of machines. We show that the problem can be solved in polyn...

We investigate the problem of semi-online scheduling jobs on m identical parallel machines where the jobs arrive in order of decreasing sizes. We present a complete solution for the preemptive variant of semi-online scheduling with decreasing job sizes. We give matching lower and upper bounds on the competitive ratio for any xed number m of machines; these bounds tend to 1 2 (1+ p 3) 1:36603, a...