15,290 research outputs found

    Multiobjective strategies for New Product Development in the pharmaceutical industry

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    New Product Development (NPD) constitutes a challenging problem in the pharmaceutical industry, due to the characteristics of the development pipeline. Formally, the NPD problem can be stated as follows: select a set of R&D projects from a pool of candidate projects in order to satisfy several criteria (economic profitability, time to market) while coping with the uncertain nature of the projects. More precisely, the recurrent key issues are to determine the projects to develop once target molecules have been identified, their order and the level of resources to assign. In this context, the proposed approach combines discrete event stochastic simulation (Monte Carlo approach) with multiobjective genetic algorithms (NSGAII type, Non-Sorted Genetic Algorithm II) to optimize the highly combinatorial portfolio management problem. In that context, Genetic Algorithms (GAs) are particularly attractive for treating this kind of problem, due to their ability to directly lead to the so-called Pareto front and to account for the combinatorial aspect. This work is illustrated with a study case involving nine interdependent new product candidates targeting three diseases. An analysis is performed for this test bench on the different pairs of criteria both for the bi- and tricriteria optimization: large portfolios cause resource queues and delays time to launch and are eliminated by the bi- and tricriteria optimization strategy. The optimization strategy is thus interesting to detect the sequence candidates. Time is an important criterion to consider simultaneously with NPV and risk criteria. The order in which drugs are released in the pipeline is of great importance as with scheduling problems

    Multiobjective strategies for New Product Development in the pharmaceutical industry

    Get PDF
    New Product Development (NPD) constitutes a challenging problem in the pharmaceutical industry, due to the characteristics of the development pipeline. Formally, the NPD problem can be stated as follows: select a set of R&D projects from a pool of candidate projects in order to satisfy several criteria (economic profitability, time to market) while coping with the uncertain nature of the projects. More precisely, the recurrent key issues are to determine the projects to develop once target molecules have been identified, their order and the level of resources to assign. In this context, the proposed approach combines discrete event stochastic simulation (Monte Carlo approach) with multiobjective genetic algorithms (NSGAII type, Non-Sorted Genetic Algorithm II) to optimize the highly combinatorial portfolio management problem. In that context, Genetic Algorithms (GAs) are particularly attractive for treating this kind of problem, due to their ability to directly lead to the so-called Pareto front and to account for the combinatorial aspect. This work is illustrated with a study case involving nine interdependent new product candidates targeting three diseases. An analysis is performed for this test bench on the different pairs of criteria both for the bi- and tricriteria optimization: large portfolios cause resource queues and delays time to launch and are eliminated by the bi- and tricriteria optimization strategy. The optimization strategy is thus interesting to detect the sequence candidates. Time is an important criterion to consider simultaneously with NPV and risk criteria. The order in which drugs are released in the pipeline is of great importance as with scheduling problems

    Cost Functions and Model Combination for VaR-based Asset Allocation using Neural Networks

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    We introduce an asset-allocation framework based on the active control of the value-at- risk of the portfolio. Within this framework, we compare two paradigms for making the allocation using neural networks. The first one uses the network to make a forecast of asset behavior, in conjunction with a traditional mean-variance allocator for constructing the portfolio. The second paradigm uses the network to directly make the portfolio allocation decisions. We consider a method for performing soft input variable selection, and show its considerable utility. We use model combination (committee) methods to systematize the choice of hyperparemeters during training. We show that committees using both paradigms are significantly outperforming the benchmark market performance. Nous introduisons un cadre d'allocation d'actifs basĂ© sur le contrĂŽle actif de la valeur Ă  risque d'un portefeuille. À l'intĂ©rieur de ce cadre, nous comparons deux paradigmes pour faire cette allocation Ă  l'aide de rĂ©seaux de neurones. Le premier paradigme utilise le rĂ©seau de neurones pour faire une prĂ©diction sur le comportement de l'actif, en conjonction avec un allocateur traditionnel de moyenne-variance pour la construction du portefeuille. Le deuxiĂšme paradigme utilise le rĂ©seau pour faire directement les dĂ©cisions d'allocation du portefeuille. Nous considĂ©rons une mĂ©thode qui accomplit une sĂ©lection de variable douce sur les entrĂ©es, et nous montrons sa trĂšs grande utilitĂ©. Nous utilisons Ă©galement des mĂ©thodes de combinaison de modĂšles (comitĂ©) pour choisir systĂ©matiquement les hyper-paramĂštres pendant l'entraĂźnement. Finalement, nous montrons que les comitĂ©s utilisant les deux paradigmes surpassent de façon significative les performances d'un banc d'essai du marchĂ©.Value-at-risk, asset allocation, financial performance criterion, model combination, recurrent multilayer neural networks, Valeur Ă  risque, allocation d'actif, critĂšre de performance financiĂšre, combinaison de modĂšles, rĂ©seau de neurones rĂ©currents multi-couches

    On the use of biased-randomized algorithms for solving non-smooth optimization problems

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    Soft constraints are quite common in real-life applications. For example, in freight transportation, the fleet size can be enlarged by outsourcing part of the distribution service and some deliveries to customers can be postponed as well; in inventory management, it is possible to consider stock-outs generated by unexpected demands; and in manufacturing processes and project management, it is frequent that some deadlines cannot be met due to delays in critical steps of the supply chain. However, capacity-, size-, and time-related limitations are included in many optimization problems as hard constraints, while it would be usually more realistic to consider them as soft ones, i.e., they can be violated to some extent by incurring a penalty cost. Most of the times, this penalty cost will be nonlinear and even noncontinuous, which might transform the objective function into a non-smooth one. Despite its many practical applications, non-smooth optimization problems are quite challenging, especially when the underlying optimization problem is NP-hard in nature. In this paper, we propose the use of biased-randomized algorithms as an effective methodology to cope with NP-hard and non-smooth optimization problems in many practical applications. Biased-randomized algorithms extend constructive heuristics by introducing a nonuniform randomization pattern into them. Hence, they can be used to explore promising areas of the solution space without the limitations of gradient-based approaches, which assume the existence of smooth objective functions. Moreover, biased-randomized algorithms can be easily parallelized, thus employing short computing times while exploring a large number of promising regions. This paper discusses these concepts in detail, reviews existing work in different application areas, and highlights current trends and open research lines

    Evaluation of the performance and of the integration of the euro zone stock market: which are the "right moments"?

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    This study intends to verify if, on the stock markets of the Euro zone, the integration as a process that lead to their unification is applied, even if several disparities exist among the national characteristics of the return-risk. We verify the pertinence of the consideration of third and fourth order moments in the comprehension of the arbitration mechanisms. The first part focuses on establishing the situation of the integration of the stock markets from the Euro zone member countries on the basis of the main characteristics of the returns and the associated risk premiums. Starting with the apparent inadequacy in the traditional theory, the second part considers the usual responses to the main questions posed on the empirical plan: non-normality of the returns distributions and non-quadratic preferences of the investors. The third part solves the apparent contradiction among the risk’s characteristics and price, on one side, and the stronger and stronger correlations among the national markets and the European indexes, on the other side.
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