A timed Petri net framework to find optimal IRIS schedules
A time-dependent best choice problem with costs and random lifetime in organ transplants
This paper develops and analyzes a time-dependent optimal stopping problem and its application to the decision making process concerning organ transplants. Offers (organs for transplant) appear at jump times of a Poisson process. The values of the offers are i.i.d. random variables with a known distribution function. These values express the degree of histocompatibility between the donor and the recipient. The sequence of offers is independent of the jump times of the Poisson process. The decision...
A Time-Predefined Approach to Course Timetabling
A tutorial on nonlinear time-series data mining in engineering asset health and reliability prediction: concepts, models, and algorithms.
A Two Warehouse Inventory Problem.
A two-level open queue network with blocking and feedback
A two-stage stochastic optimization model for a gas sale retailer
The paper deals with a new stochastic optimization model, named OMoGaS–SV (Optimization Modelling for Gas Seller–Stochastic Version), to assist companies dealing with gas retail commercialization. Stochasticity is due to the dependence of consumptions on temperature uncertainty. Due to nonlinearities present in the objective function, the model can be classified as an NLP mixed integer model, with the profit function depending on the number of contracts with the final consumers, the typology of...
A Unified Approach to Optimal Process Control.
A unified cost function for M/G/1 queueing systems with removable server.
This article deals with the three classic policies for an M/G/1 queueing system (N, T, and D-policy). The optimum policies were compared in several precedent studies, but the comparison was performed employing different cost functions, so that the D-policy is superior to the N-policy when the cost function is based on the mean work-load, whilst the average queue length is used to show the superiority of the N-policy over the T-policy. In order to achieve a comparison of the three policies under...
A variational model for equilibrium problems in a traffic network
We propose a variational model for one of the most important problems in traffic networks, namely, the network equilibrium flow that is, traditionally in the context of operations research, characterized by minimum cost flow. This model has the peculiarity of being formulated by means of a suitable variational inequality (VI) and its solution is called “equilibrium”. This model becomes a minimum cost model when the cost function is separable or, more general, when the jacobian of the cost operator...
A variational model for equilibrium problems in a traffic network
We propose a variational model for one of the most important problems in traffic networks, namely, the network equilibrium flow that is, traditionally in the context of operations research, characterized by minimum cost flow. This model has the peculiarity of being formulated by means of a suitable variational inequality (VI) and its solution is called “equilibrium”. This model becomes a minimum cost model when the cost function is separable or, more general, when the Jacobian of the cost operator...
A variational model for urban planning with traffic congestion
We propose a variational model to describe the optimal distributions of residents and services in an urban area. The functional to be minimized involves an overall transportation cost taking into account congestion effects and two aditional terms which penalize concentration of residents and dispersion of services. We study regularity properties of the minimizers and treat in details some examples.
A variational model for urban planning with traffic congestion
We propose a variational model to describe the optimal distributions of residents and services in an urban area. The functional to be minimized involves an overall transportation cost taking into account congestion effects and two aditional terms which penalize concentration of residents and dispersion of services. We study regularity properties of the minimizers and treat in details some examples.
A Windows interface for maritime navigator training.
About integrity in security models.
About the choice of the variable to unassign in a decision repair algorithm
The decision repair algorithm (Jussien and Lhomme, Artificial Intelligence 139 (2002) 21–45), which has been designed to solve constraint satisfaction problems (CSP), can be seen, either (i) as an extension of the classical depth first tree search algorithm with the introduction of a free choice of the variable to which to backtrack in case of inconsistency, or (ii) as a local search algorithm in the space of the partial consistent variable assignments. or (iii) as a hybridisation between local...
About the choice of the variable to unassign in a decision repair algorithm
The decision repair algorithm (Jussien and Lhomme, Artificial Intelligence139 (2002) 21–45), which has been designed to solve constraint satisfaction problems (CSP), can be seen, either (i) as an extension of the classical depth first tree search algorithm with the introduction of a free choice of the variable to which to backtrack in case of inconsistency, or (ii) as a local search algorithm in the space of the partial consistent variable assignments. or (iii) as a hybridisation between local...
About the cumulative idle time in multiphase queues
The paper is designated to the analysis of queueing systems, arising in the network theory and communications theory (called multiphase queueing systems, tandem queues or series of queueing systems). Also we note that multiphase queueing systems can be useful for modelling practical multi-stage service systems in a variety of disciplines, especially on manufacturing (assembly lines), computer networking (packet switch structures), and in telecommunications (e.g. cellular mobile networks), etc. This...
About the cumulative idle time in multiphase queues
The paper is designated to the analysis of queueing systems, arising in the network theory and communications theory (called multiphase queueing systems, tandem queues or series of queueing systems). Also we note that multiphase queueing systems can be useful for modelling practical multi-stage service systems in a variety of disciplines, especially on manufacturing (assembly lines), computer networking (packet switch structures), and in telecommunications (e.g. cellular mobile networks), etc....
ABR traffic control over multisource single-bottleneck ATM networks
The problem of flow control in fast, connection-oriented communication networks supporting the traffic generated by multiple sources is considered. A novel sampled time strategy governing the behaviour of the sources is proposed. The strategy combines the Smith principle with the conventional sampled time proportional controller. It guarantees an equal resource allocation between various users, full bottleneck link utilisation and no cell loss in the controlled network. Consequently, the need for...