377 research outputs found
A game theory framework for clustering
The Game Theory-based Multi-Agent System (GTMAS) of Toreyen and Salhi, [10] and [12], implements a loosely coupled hybrid algorithm that may involve any number of algorithms suitable, a priori, for the solution of a given optimisation problem. The system allows the available algorithms to co-operate toward the solution of the problem in hand as well as compete for the computing facilities they require to run. This co-operative/competitive aspect is captured through the implementation of the Prisoners? Dilemma paradigm of game theory. Here, we apply GTMAS to the problem of clustering European Union (EU) economies, including Turkey, to find out whether the latter, based on a number of criteria, can fit in the EU and find out which countries, if any, it has strong similaries with. This clustering problem is first converted into an optimisation problem, namely the Travelling Salesman Problem (TSP) before being solved with GTMAS involving two players (agents) each implementing a standard combinatorial optimisation algorithm. Computational results are included
A comparative study of two key algorithms in multiple objective linear programming
Multiple objective linear programming problems are solved with a variety of algorithms. While these algorithms vary in philosophy and outlook, most of them fall into two broad categories: those that are decision space-based and those that are objective space-based. This paper reports the outcome of a computational investigation of two key representative algorithms, one of each category, namely the parametric simplex algorithm which is a prominent representative of the former and the primal variant of Bensons Outer-approximation algorithm which is a prominent representative of the latter. The paper includes a procedure to compute the most preferred nondominated point which is an important feature in the implementation of these algorithms and their comparison. Computational and comparative results on problem instances ranging from small to medium and large are provided
A Comparison of Bensonâs Outer Approximation Algorithm with an Extended Version of Multiobjective Simplex Algorithm
The multiple objective simplex algorithm and its variants work in the decision variable space to find the set of all efficient extreme points of multiple objective linear programming (MOLP). Other approaches to the problem find either the entire set of all efficient solutions or a subset of them and also return the corresponding objective values (nondominated points). This paper presents an extension of the multiobjective simplex algorithm (MSA) to generate the set of all nondominated points and no redundant ones. This extended version is compared to Bensonâs outer approximation (BOA) algorithm that also computes the set of all nondominated points of the problem. Numerical results on nontrivial MOLP problems show that the total number of nondominated points returned by the extended MSA is the same as that returned by BOA for most of the problems considered
On the simplex, interior-point and objective space approaches to multiobjective linear programming
Most Multiple Objective Linear Programming (MOLP) algorithms working in the decision variable space, are based on the simplex algorithm or interior-point method of Linear Programming. However, objective space based methods are becoming more and more prominent. This paper investigates three algorithms namely the Extended Multiobjective Simplex Algorithm (EMSA), Arbelâs Affine Scaling Interior-point (ASIMOLP) algorithm and Bensonâs objective space Outer Approximation (BOA) algorithm. An extensive review of these algorithms is also included. Numerical results on non-trivial MOLP problems show that EMSA and BOA are at par and superior in terms of the quality of a most preferred nondominated point to ASIMOLP. However, ASIMOLP more than holds its own in terms of computing efficiency
Ethnobotany Study of Medicinal Plants Used in the Treatment of Respiratory Diseases in the Middle Region of Oum Rbai
The ethnobotanical study carried out in the region of Oum Rbia (Morocco) made it possible to identify the medicinal plants used by the local population and to collect the maximum information on this use.
A survey of 1360 people from the region's population noted that 170 people use medicinal plants against respiratory diseases. Women accounted for 55.3% of the workforce versus 44.7% for men; Married people 70% against 28% for singles. The illiteracy rate is high (34.1%).
The leaves are the most widely used part of the plant. Infusion and decoction are the most commonly used methods for preparing traditional remedies.
The most widely used species in the treatment of respiratory diseases are: Origanun glandulosum, Eucalyptus globulus, Nigella sativa, Mentha pulegium, Lavandula stoechas, Zingiber officinale, Ammodaucus leucotrichus, Ficus carica. In addition, some species have toxicity either because of the ignorance of the necessary dose or because the people treated are affected by other diseases.
Thus, the survey made it possible to inventory 66 medicinal species which are divided into 36 plant families; Lamiaceae (21.2%), Myrtaceae (10.6%), Apiaceae (8.8%), Amaryllydaceae (7.7%) and Zingiberaceae (7.1%).
These results resulted in a catalog of medicinal plants used in the study area to treat respiratory diseases. It is a local know-how that must be considered as a heritage to be preserved and developed
Endurance and Resistance Training in Radically Treated Respiratory Cancer patients: A Pilot Study
Introduction. Respiratory cancer and its treatment are known to contribute to muscle weakness and functional impairment. Aim. To assess the effects of rehabilitation in patients with respiratory cancer. Methods. Radically treated respiratory cancer patients were included in a 12-week multidisciplinary rehabilitation program. Results. 16 patients (age: 61 ± 7 years; FEV1: 57 ± 16% pred.) showed a reduced exercise tolerance (VO2max: 56 ± 15% pred.; 6 MWD: 67 ± 11% pred.), muscle force (PImax: 54 ± 22% pred.; QF: 67 ± 16% pred.), and quality of life (CRDQd: 17 ± 5 points; CRDQf: 16 ± 5 points). Exercise tolerance, muscle force, and quality of life improved significantly after rehabilitation. Conclusion. Radically treated patients with respiratory cancer have a decreased exercise capacity, muscle force, and quality of life. 12 weeks of rehabilitation leads to a significant improvement in exercise capacity, respiratory muscle force, and quality of life
Surface-related properties of perovskite CH3NH3PbI3 thin films by aerosol-assisted chemical vapour deposition
A modified three-step aerosol-assisted chemical vapour deposition process was used to grow dense and uniform CH3NH3PbI3 thin films directly on borosilicate glass. The resulting photoluminescence spectrum was blue shifted with respect to its bandgap. X-ray photoelectron spectroscopy studies confirmed non-stoichiometric lead : iodine ratios within the films, due to decomposition of the CH3NH3PbI3 layers over time into lead iodide and the release of ammonia and hydrogen iodide. The complex refractive index and dielectric function of the deposited thin films were determined by variable angle spectroscopic ellipsometry
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