Search results for "optimal"
showing 10 items of 706 documents
Invitation to participate in a multi-center study for validation of cerebral computed tomography angiography and computed tomography perfusion in the…
2021
In recent years commensal microorganisms are not just “passive occupants”, but important element of homeostasis. There are numerous reports documenting the composition and role of the gut, skin or vagina microbiome but the role of commensal organisms living in the lungs is relatively unknown. Pulmonary microbiome impact on the immune response of the host organism and may indicate new therapeutic directions. Lung microbiome, by modulating the expression of innate immunity genes, causes an increase in the concentration of IL-5, IL-10, IFNγ and CCL11, affects the TLR4 dependent response of pulmonary macrophages and modulate the production of antibacterial peptides contained in the mucus. It is…
On the methods of nonsmooth optimization
2005
In this paper we shall give a short derivation of the most promising methods in nonsmooth optimization, namely bundle methods. We introduce the basic bundle idea due to Lemarechal and several modifications by Kiwiel, Schramm and Zowe. To the end we shall give some numerical results comparing the efficience of these methods. As test problems we have used well-known test problems from litterature and in addition we shall give some contributions to nonsmooth optimal control problems.
Evaluation of Hemodynamic Parameters for Adaptive Control of the Artificial Heart by Simulation of the Vascular System
1984
Abstract A nonlinear dynamic mathematical model of the cardiovascular system is outlined, which is employable to analyse the hemodynamic system behaviour under normal as well as under pathological conditions. By modifying this model, assuming that cardiac output is constant at a preset level (which is in accordance with most of the total artificial heart systems, since their pumps output is preselected with fixed driving parameters), the hemodynamic behaviour of a circulation system with an artificial heart was simulated. Comparing the simulation results with those obtained from total artificial heart experiments, a good agreement in right atrial and aortic pressure under exercise condition…
Experimental Study of Central Baffle Flume
2019
In this paper, the hydraulics of a central baffle flume (CBF) were experimentally studied. Extensive experimental runs were carried out to highlight the effects of different geometrical parameters such as baffle length, contraction ratio, and the length of upstream and downstream guide walls. Two different approaches, i.e., the Π theorem of dimensional analysis coupled with the incomplete self-similarity theory and the energy balance equation, were applied to deduce the stage–discharge formula of a CBF characterized by different geometrical parameters. The stage–discharge relationship deduced by the dimensional analysis approach was more accurate than that obtained by the energy approach. F…
Changements de stratégie temporelle durant des tâches motrices complexes chez des sujets âgés sains
2017
International audience; Cette étude a permis d’analyser des points temporels clefs de la réalisation de mouvements impliquant l’ensemble du corps (Whole Body Reaching movements - WBR). Lors de ce mouvement, le sujet déplace son Centre de Masse (CdM) vers l’avant pour l’atteindre une cible. Ceci implique une inclinaison du tronc créant des modifications posturales et un risque de chute. Ces différentes considérations nous ont poussées à étudier une population de sujets âgés (SA) en comparaison à des sujets jeunes (SJ). Nous avons analysé des points stratégiques au cours de la tâche, dont deux plus particulièrement. La décomposition axiale de la vitesse du CdM en deux composantes (Verticale-V…
Analysing Incentive Strategies to Promote Participation in Crowdsourcing Systems
2016
In this paper, we define two strategies for crowdsourcing systems to encourage users to participate at a cost that is close to the optimal cost for the system. In the scenario considered, the system has temporal constraints and potential participants have dynamic behaviors related to the expected rewards (i.e., users’ expected rewards in exchange of their contributions change over time). We propose and evaluate two types of strategies that promote participation of users through monetary rewards that can change as time passes in order to adapt them to the population dynamic behaviors.
Una procedura sequenziale di stima di punto di cambiamento
2008
In this paper we propose a sequential procedure for the estimation of a change-point when a change has occurred in the distribution that governs the process which generates the observations. The procedure applies whether the distribution functions involved are completely specified or they contain unknown parameters to be estimated. The procedure is based on the Kolmogorov-Smirnov test of goodness of fit, or an appropriate different test such as the chi-square test, and satisfies the optimality condition defined by the maximization of the sum of the p-values involved.
On interactive multiobjective optimization with NIMBUS® in chemical process design
2005
We study multiobjective optimization problems arising from chemical process simulation. The interactive multiobjective optimization method NIMBUS®, developed at the University of Jyvaskyla, is combined with the BALAS® process simulator, developed at the VTT Technical Research Center of Finland, in order to provide a new interactive tool for designing chemical processes. Continuous interaction between the method and the designer provides a new efficient approach to explore Pareto optimal solutions and helps the designer to learn about the behaviour of the process. As an example of how the new tool can be used, we report the results of applying it in a heat recovery system design problem rela…
Tertiary cytoreduction in the setting of recurrent ovarian cancer (Review)
2013
Ovarian cancer is the most lethal gynecological malignancy, with aggressive surgical debulking and adjuvant chemotherapy as the main treatment modalities. Optimal debulking during the primary surgery is significantly correlated with prolonged survival. As surgical techniques and chemotherapeutic agents improve, more patients with prolonged survival may face secondary and tertiary recurrences. The role of surgical debulking in secondary cytoreduction (SC) is not clearly defined and is based on retrospective series. The treatment of patients with primary or secondary recurrences generally consists of second-line chemotherapy, but may be performed on medically fit patients in certain circumsta…
Maximum weight relaxed cliques and Russian Doll Search revisited
2015
Trukhanov et al. [Trukhanov S, Balasubramaniam C, Balasundaram B, Butenko S (2013) Algorithms for detecting optimal hereditary structures in graphs, with application to clique relaxations. Comp. Opt. and Appl., 56(1), 113–130] used the Russian Doll Search (RDS) principle to effectively find maximum hereditary structures in graphs. Prominent examples of such hereditary structures are cliques and some clique relaxations intensely discussed and studied in network analysis. The effectiveness of the tailored RDS by Trukhanov et al. for s-plex and s-defective clique can be attributed to their cleverly designed incremental verification procedures used to distinguish feasible from infeasible struct…