Displaying 61 – 80 of 96

Showing per page

Process parameter prediction via markov models of sub-activities

Lino G. Marujo, Raad Y. Qassim (2014)

RAIRO - Operations Research - Recherche Opérationnelle

This work aims to fill a lacunae in the project-oriented production systems literature providing a formal analytic description of the rework effects formulae and the determination of the extended design time due to a certain degree of overlapping in a pair of activities. It is made through the utilization of concepts of workflow construction with hidden (semi) Markov models theory and establishing a way to disaggregate activities into sub-activities, in order to determine the activity parameters...

Scheduling multiprocessor tasks on two parallel processors

Jacek Błażewicz, Paolo Dell'Olmo, Maciej Drozdowski (2002)

RAIRO - Operations Research - Recherche Opérationnelle

In this work scheduling multiprocessor tasks on two parallel identical processors is considered. Multiprocessor tasks can be executed by more than one processor at the same moment of time. We analyze scheduling unit execution time and preemptable tasks to minimize schedule length and maximum lateness. Cases with ready times, due-dates and precedence constraints are discussed.

Scheduling multiprocessor tasks on two parallel processors

Jacek Błażewicz, Paolo Dell'Olmo, Maciej Drozdowski (2010)

RAIRO - Operations Research

In this work scheduling multiprocessor tasks on two parallel identical processors is considered. Multiprocessor tasks can be executed by more than one processor at the same moment of time. We analyze scheduling unit execution time and preemptable tasks to minimize schedule length and maximum lateness. Cases with ready times, due-dates and precedence constraints are discussed.

Scheduling precedence task graphs with disturbances

Apurv Gupta, Gilles Parmentier, Denis Trystram (2003)

RAIRO - Operations Research - Recherche Opérationnelle

In this paper we consider the problem of scheduling precedence task graphs in parallel processing where there can be disturbances in computation and communication times. Such a phenomenon often occurs in practice, due to our inability to exactly predict the time because of system intrusion like cache miss and packet transmission time in mediums like ethernet etc. We propose a method based on the addition of some extra edges to protect the initial scheduling from performing badly due to such changes...

Scheduling Precedence Task Graphs with Disturbances

Apurv Gupta, Gilles Parmentier, Denis Trystram (2010)

RAIRO - Operations Research

In this paper we consider the problem of scheduling precedence task graphs in parallel processing where there can be disturbances in computation and communication times. Such a phenomenon often occurs in practice, due to our inability to exactly predict the time because of system intrusion like cache miss and packet transmission time in mediums like ethernet etc. We propose a method based on the addition of some extra edges to protect the initial scheduling from performing badly due to such...

Scheduling UET Trees with Communication Delays on two Processors

Frederic Guinand, Denis Trystman (2010)

RAIRO - Operations Research

In this paper, we present a new linear time algorithm for scheduling UECT (Unit Execution and Communication Time) trees on two identical processors. The chosen criterion is the makespan. The used strategy is based on clustering of tasks. We show that this algorithm builds optimal schedules. Some extensions are discussed for non UECT tasks.

Secuenciación dinámica de sistemas de fabricación flexible mediante aprendizaje automático: análisis de los principales sistemas de secuenciación existentes.

Paolo Priore, David de la Fuente, Javier Puente, Alberto Gómez (2001)

Qüestiió

Una forma habitual de secuenciar de modo dinámico los trabajos en los sistemas de fabricación es mediante el empleo de reglas de secuenciación. Sin embargo, el problema que presenta este método es que el comportamiento del sistema de fabricación dependerá de su estado, y no existe una regla que supere a las demás en todos los posibles estados que puede presentar el sistema de fabricación. Por lo tanto, sería interesante usar en cada momento la regla más adecuada. Para lograr este objetivo, se pueden...

Simulated Annealing and Tabu Search for Discrete-Continuous Project Scheduling with Discounted Cash Flows

Grzegorz Waligóra (2014)

RAIRO - Operations Research - Recherche Opérationnelle

Discrete-continuous project scheduling problems with positive discounted cash flows and the maximization of the NPV are considered. We deal with a class of these problems with an arbitrary number of discrete resources and one continuous, renewable resource. Activities are nonpreemptable, and the processing rate of an activity is a continuous, increasing function of the amount of the continuous resource allotted to the activity at a time. Three common payment models – Lump Sum Payment, Payments at...

Solving a permutation problem by a fully polynomial-time approximation scheme

Stanisław Gawiejnowicz, Wiesław Kurc, Lidia Pankowska (2010)

Discussiones Mathematicae, Differential Inclusions, Control and Optimization

For a problem of optimal discrete control with a discrete control set composed of vertices of an n-dimensional permutohedron, a fully polynomial-time approximation scheme is proposed.

Some aspects of balking and reneging in finite buffer queues

Amit Choudhury, Pallabi Medhi (2011)

RAIRO - Operations Research

In this paper, a single server finite buffer Markovian queuing system is analyzed with the additional restriction that customers may balk as well as renege. Reneging considered in literature is usually of position independent type where the reneging rate is constant irrespective of the position of the customer in the system. However there are many real world situations where this assumption does not hold. This paper is an attempt to model balking with position dependent reneging. Explicit closed...

Some aspects of balking and reneging in finite buffer queues

Amit Choudhury, Pallabi Medhi (2011)

RAIRO - Operations Research

In this paper, a single server finite buffer Markovian queuing system is analyzed with the additional restriction that customers may balk as well as renege. Reneging considered in literature is usually of position independent type where the reneging rate is constant irrespective of the position of the customer in the system. However there are many real world situations where this assumption does not hold. This paper is an attempt to model balking with position dependent reneging. Explicit closed...

Study of Queuing Systems with a Generalized Departure Process

Mirtchev, Seferin, Statev, Stanimir (2008)

Serdica Journal of Computing

This work was supported by the Bulgarian National Science Fund under grant BY-TH-105/2005.This paper deals with a full accessibility loss system and a single server delay system with a Poisson arrival process and state dependent exponentially distributed service time. We use the generalized service flow with nonlinear state dependence mean service time. The idea is based on the analytical continuation of the Binomial distribution and the classic M/M/n/0 and M/M/1/k system. We apply techniques based...

Currently displaying 61 – 80 of 96