Showing papers by "Congrès International d'Architecture Moderne published in 2017"

Collaborative System of Systems Multidisciplinary Design Optimization for Civil Aircraft: AGILE EU project

Abstract: As part of H2020 EU project "AGILE", A Collaborative System of Systems Multidisciplinary Design Optimization research approach is presented in this paper This approach relies on physics-based analysis to evaluate the correlations between the airframe design, as well as propulsion, aircraft systems, aerodynamics, structures and emission, from the early design process, and to exploit the synergies within a simultaneous optimization process Further, the disciplinary analysis modules from multiple organizations, involved in the optimization are integrated within a distributed framework The disciplinary analysis tools are not shared, but only the data are distributed among partners through a secured network of framework In order to enable and to accelerate the deployment of collaborative, large scale design and optimization frameworks, the "AGILE Paradigm", a novel methodology, has been formulated during the project The main elements composing the AGILE Paradigm are the Knowledge Architecture (KA), and the Collaborative Architecture (CA) The first formalizes the overall product development process in a multi-level structure The latter formalizes the collaborative process within the entire supply chain, and defines how the multiple stakeholders interact with each otherThe current paper is focused on the application of using the AGILE Paradigm to solve system of stystems MDO on a regional jet transport aircraft The focus of the current research paper is: 1) Creation of a system of systems frame work using AGILE Paradigm to support multidisciplinary distributive analysis capability The framework involves physics based modules such as : Airframe synthesis, aerodynamics, structures, aircraft systems , propulsion system design, nacelle design, nacelle airframe integration, aircraft mission simulation,costs and emissions 2) Validate the frame work with case study of a regional jet reference aircraft 3) Assess the sensitivity and coupling of design parameters, local disciplinary optimizataion and its effect on global optimization objectives or constraints The effects of varying Bypass Ratio (BPR) of engine, offtake effects due to degree of electrification and nacelle effects are propagated through the AGILE MDO framework and presented

Photodegradation of multiclass fungicides in the aquatic environment and determination by liquid chromatography-tandem mass spectrometry

Abstract: The photodegradation behaviour for nine widespread fungicides (benalaxyl, cyprodinil, dimethomorph, fenhexamide, iprovalicarb, kresoxim-methyl, metalaxyl, myclobutanil and tebuconazole) was evaluated in different types of water. Two different systems, direct UV photolysis and UVC/H2O2 advanced oxidation process (AOP), were applied for the photodegradation tests. For the monitoring of the target compound degradation, a method based on direct injection liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. Several fungicide photodegradation by-products were tentatively identified by high-resolution mass spectrometry (HRMS) as well. For the photolysis studies, the efficiency of different types of radiation, UVC (λ = 254 nm) and UVA (λ = 365 nm), was compared. UVC photolysis provided the highest removal with a complete degradation for fenhexamide and kresoxim-methyl, and percentages between 48 and 78% for the other compounds, excluding iprovalicarb and myclobutanil with removals <35%, after 30 min of irradiation. Besides, the photodegradation tests were performed with different initial concentrations of fungicides, and the efficiency of two photoreactor systems was compared. In all cases, the kinetics followed pseudo-first order, and the half-life times could also be calculated. The addition of H2O2 under UVC light allowed an improvement of the reaction kinetics, especially for the most recalcitrant fungicides, obtaining in all cases removals higher than 82% in less than 6 min. Finally, in order to evaluate the suitability of the proposed systems, both UVC photolysis and UVC/H2O2 system were tested in different real water matrices (wastewater, tap water, swimming pool water and river water), showing that the UVC/H2O2 system had the highest removal efficiency in less than 6 min, for all water samples.

Investigation of flows induced by subsonic turbulent jets and their relation with the effect of static pressure reduction in a jet

Abstract: The interaction between turbulent jets, both swirling and nonswirling, and the ambient medium is studied on the basis of the results of measurements and numerical simulation. It is shown that the turbulent flow and the swirl give rise to induced ejection flow toward the jet. The mechanism of the jet action on the ambient medium is connected with a decrease in the static pressure in the jet, which, in turn, is due to either the flow swirl or the fluctuating flow in the mixing layer, when the static pressure reduces owing to the presence of velocity fluctuations. The former rarefaction mechanism is predominant in swirling jets and the latter predominates in jets without swirling. It is shown that the ambient medium inflow into the jet due to the rarefaction is independent in nature of the mechanism of the lowered pressure generation and that it is the kinetic energy of the jet that is the energy source for the induced flow.

Frequency-domain method for multistage turbomachine tone noise calculation

Abstract: A method of frequency-domain calculation of the multistage turbomachinery tone noise is presented The method is based on the kinematic relations featuring dependence of flow fields in a turbomachi

Comparison of the efficiencies of spike and combined annular nozzles

Abstract: The comparative efficiency of two layouts of self-adjusted annular nozzles operating over a wide flight altitude range is studied. One of the layouts is presented by the so-called spike nozzles (plane or antisymmetric, with a central body) having the property of self-adjustment when operating in different regions of the flight trajectory. The possibility of locating an annular plug nozzle or a conventional round nozzle in the base region of an axisymmetric spike is considered as a possible means for reducing its base losses. Two layouts of annular self-adjusted nozzles (in combination with internal nozzles or without them) are optimized for the mean thrust in operation in the launch and altitude flight regimes using the “classical” and “genetic” approaches. It is shown that optimal annular spike nozzles in combination with internal nozzles do not provide considerable advantages in the thrust compared with purely spiked optimal configurations. At the same time, an effective optimization of spike nozzles with account for the contribution made by the base thrust can ensure a comparatively low level of the losses.

Methodology of experimental determining the combustion efficiency of fuel mixture flows in channels of variable cross-section

Abstract: The physically validated approaches to the setting of an experiment are presented and the methodological aspects of an analysis of experimental data for establishing the distinctive features of the fuel mixture combustion in variable-cross-section channels are considered. The special features of determining the fuel combustion efficiency coefficient in subsonic and supersonic flows are considered with account for heat removal into the channel walls. The effect of the fuel combustion efficiency coefficient on the distributions of gasdynamic and thermodynamic parameters along the length of the internal ducts of channels of different configurations is analyzed. The results of the testing of the techniques proposed against an experimental investigation of gaseous hydrogen combustion in high-enthalpy air flows are presented. The results obtained and the mathematical models developed can be used at the stage of computational and experimental investigations of the working process in promising power plants.

Susceptible infected removed epidemic model extension for efficient analysis of ebola virus disease transmission

Abstract: The analysis of epidemic diseases based on the Susceptible Infected Susceptible (SIS) epidemic model and its extensions have received wide application over the years. However, recent investigations indicated a threestep transmission phase that is unique for Ebola Virus Disease (EVD) only. This paper examined the existing SIS based epidemic models and its extensions to establish the need for an improved model pertinent for EVD problems. Subsequently, an EVD Susceptible Infected Removed (SIR) based epidemic model was proposed and found relevant for the analysis of EVD problems based on the three-step transmission phases.

A simulated annealing approach for redesigning a warehouse network problem

Abstract: Now a day, several companies consider downsizing their distribution networks in ways that involve consolidation or phase-out of some of their current warehousing facilities due to the increasing competition, mounting cost pressure and taking advantage on the economies of scale Consequently, the changes on economic situation after a certain period of time require an adjustment on the network model in order to get the optimal cost under the current economic conditions This paper aimed to develop a mixed-integer linear programming model for a two-echelon warehouse network redesign problem with capacitated plant and uncapacitated warehouses The main contribution of this study is considering capacity constraint for existing warehouses A Simulated Annealing algorithm is proposed to tackle with the proposed model The numerical solution showed the model and method of solution proposed was practical

Possible mechanism of self-oscillations in a combustor working on a premixed methane/air mixture

Abstract: The process of combustion of a premixed lean methane/air mixture in the model low-emission combustor is studied. Several known mechanisms of the self-oscillation generation and the flame flashback are analyzed. Numerical LES and SAS calculations of several combustors of typical configurations and regime parameters are presented. Some means of suppressing the flame flashback are proposed and analyzed.

An Enhanced Simulated Annealing Routing Algorithm for Semi-Diagonal Torus Network

Abstract: Multiprocessor is another great technology that helps in advancing human civilization due to high demands for solving complex problems. A multiprocessing system can have a lot of replicated processor-memory pairs (henceforth regard as net) or also called as processing nodes. Each of these nodes is connected to each other through interconnection networks and passes message using a standard message passing mechanism. In this paper, we present a routing algorithm based on enhanced simulated annealing technique to provide the connection between nodes in a semi-diagonal torus (SD-Torus) network. This network is both symmetric and regular; thus, make it very beneficial in the implementation process. The main objective is to maximize the number of established connection between nodes in this SD-Torus network. In order to achieve this objective, each node must be connected in its shortest way as possible. We start our algorithm by designing shortest path algorithm based on Dijkstra's method. While this algorithm guarantees to find the shortest path for each single net, if it exists, each routed net will form obstacle for later paths. This increases the complexity to route later nets and makes routing longer than optimal, or sometimes impossible to complete. The solution is further refined by re-routing all nets in different orders using simulated annealing method. Through simulation program, our proposed algorithm succeeded in performing complete routing up to 81 nodes with 40 nets in 9×9 SD-Torus network size.

The effect of body acceleration on the generalized power law model of blood flow in a stenosed artery

Abstract: Unsteady blood flow characterized by the generalized power law model in a stenosed artery subject to external body acceleration is considered numerically using the Marker and Cell finite difference discretization on staggered grid, where the pressure is calculated iteratively using the successive-over-relaxation method. The codes have been developed and the results analysed using Matlab. The focus of discussion is on the effects of body acceleration on the flow characteristics, in particular its effects on the wall pressure, pressure drop and the streamlines as these results have not yet been presented and discussed in previous works.

Solving integral equations with generalized Neumann kernel using global simpler GMRES for numerical conformal mapping

Abstract: We study a numerical approach for solving integral equation with adjoint generalized Neumann kernel related to conformal mapping. Previously, computation of conformal mapping of M + 1 connected regions require solving at least M + 1 integral equations with adjoint generalized Neumann kernel separately. We apply global simpler GMRES which solve nonsymmetric system with multiple right-hand sides to solve M + 1 integral equations simultaneously. We also apply fast multipole method for several matrix vector products in every iteration of global simpler GMRES. Numerical example is given to illustrate the effectiveness of the proposed method.

Conformal mapping of unbounded multiply connected regions onto logarithmic spiral slit with infinite straight slit

Abstract: This paper presents a boundary integral equation method with the adjoint generalized Neumann kernel for conformal mapping of unbounded multiply connected regions. The canonical region is the entire complex plane bounded by an infinite straight slit on the line Im ω = 0 and finite logarithmic spiral slits. Some linear boundary integral equations are constructed from a boundary relationship satisfied by an analytic function on a multiply connected region. These integral equations are uniquely solvable. The kernel involved in these integral equations is the adjoint generalized Neumann kernel.

Plant breeding as tool to challenge climatic changes in forage production. a review = la mejora genética vegetal como herramienta para afrontar los cambios climáticos en la producción de forraje. una revisión

Abstract: Literature was reviewed concerning climatic changes, especially increase in carbon dioxide concentration [CO2] and temperature during the last centuries, and connecting these changes with biochemical pathways in plants, mainly photosynthesis activity and respiration. Plant breeding has been successful in moving the genome of plants for selecting different characteristics, such as high oil and protein of the maize kernel, increase of yield in several crops along different eras, resistance to diseases and pests and adaptation to environmental conditions. Therefore plant breeding is proposed as a tool to challenge the climatic change through development of new varieties with complex traits adapted to future environments, such as higher temperatures and lower rainfall. Utilization of natural or induced polyploidy has demonstrated to be a good aid to increase vigor, yield, resistance to diseases, and adaptation of forage crops to stress. Development of synthetic varieties for forage plants seems to be a good option for achieving breeding goals in cross-pollinated crops. Hybridization between different species and within species is sometimes used for increasing the vigor, the adaptation to environmental stress and the yield of cultivars. Hybrids between two species (e.g., from genus Lolium) produce usually a high rate of aneuploid plants in the F1 generation. Recurrent selection for raising the rate of balanced euploid plants in the F1, F2, F3, F4…generations of the aloploid hybrids is needed for getting stable varieties adapted to the target stress. Commercial hybrid seed is preferred to synthetics provided that the additional yield and features compensate the extra cost of seed production. Results of forage maize hybrids related to the worldwide cultivated “B73 × Mo17” hybrid, which were selected for earliness, are presented. Exploration of new C4 tropical species, such as Teff, likely will help to produce forage in poor watering conditions. The use of 13C isotopic discrimination seems to be a good indicator to breed for water use efficiency (WUE) in C3 plants. Biotechnological tools, such as molecular markers, will facilitate to achieve breeding objectives sooner. Breeding suggestions for development of new varieties in C3 and C4 species adapted to future environments should consider the possible biotic and abiotic stresses generated by the climatic change. Automated phenotyping platforms are used for simulating stress environments. Domestication of wild species may be an alternative for developing a new crop to meet the requirement of environmental change. Crop domestication is a difficult task; however the use of rational strategies, including breeding for reducing the effect of limiting factors and strengthening favorable traits will help to achieve the desired objectives. Use of autochthonous germplasm as base material is crucial for providing genetic variability and genes adapted to environmental conditions. RESUMEN Se reviso la literatura en lo referente al cambio climatico, especialmente al aumento de la concentracion de dioxido de carbono [CO2] y la temperatura durante los ultimos siglos, asi como su relacion con las rutas bioquimicas en plantas, principalmente la actividad fotosintetica y la respiracion. La mejora genetica de plantas ha tenido exito en cambiar el genoma de las plantas seleccionando diversas caracteristicas, tales como alto contenido de aceite y proteina en el grano de maiz, aumento del rendimiento en varios cultivos durante diferentes eras, resistencia a plagas y enfermedades y adaptacion a las condiciones ambientales. Por lo tanto se propone a la mejora genetica de plantas como una herramienta util para afrontar el cambio climatico mediante el desarrollo de nuevas variedades con caracteres complejos adaptados a los ambientes futuros. La utilizacion de la poliploidia natural o inducida ha demostrado ser una buena ayuda para aumentar el vigor, rendimiento, resistencia a enfermedades y adaptacion de cultivos forrajeros a estres. El desarrollo de variedades sinteticas en plantas pratenses parece ser una buena opcion para alcanzar los objetivos de mejora en cultivos de polinizacion cruzada. La hibridacion entre especies y dentro de especies gramineas y leguminosas forrajeras se utiliza para aumentar el vigor, la adaptacion al estres y el rendimiento de las variedades. Hibridos entre dos especies (e.g. del genero Lolium) producen generalmente una alta tasa de plantas aneuploides en la generacion F1. La seleccion recurrente para elevar la tasa de plantas euploides (i.e. con equilibrio cromosomico) en las generaciones F1, F2, F3, F4… del hibrido aloploide es necesaria para obtener variedades estables adaptadas al estres. La semilla hibrida comercial se prefiere a las variedades sinteticas siempre que el incremento del rendimiento y otras caracteristicas compensen el coste adicional de produccion de semilla. Se presentan los resultados de hibridos de maiz forrajero relacionados con el hibrido ampliamente cultivado B73 x Mo17 y seleccionados para precocidad. La exploracion de nuevas especies tropicales C4, tal como Teff, ayudara probablemente a producir forraje en condiciones de sequia y calor. El uso de la discriminacion isotopica 13C parece ser un buen indicador para mejorar la eficiencia en el uso del agua (EUA) en plantas C3. Las herramientas biotecnologicas, tales como marcadores moleculares, facilitaran alcanzar mas pronto los objetivos de mejora genetica. Se sugiere que la mejora genetica durante el proceso de desarrollo de nuevas variedades en plantas C3 y C4 adaptadas a los ambientes futuros debera tener en cuenta los estreses bioticos y abioticos generados por el cambio climatico. La domesticacion de especies silvestres puede ser una alternativa para obtener un nuevo cultivo que cumpla los requisitos del cambio ambiental. Plataformas automatizadas de fenotipado se utilizan para simular ambientes de estres. La domesticacion para desarrollar un cultivo es una tarea dificil; sin embargo el uso de estrategias racionales, incluyendo la mejora genetica para conseguir eliminar factores limitantes y fortalecer los rasgos favorables ayudara a lograr los objetivos deseados. El uso de germoplasma autoctono como material base es esencial para proporcionar variabilidad genetica y genes adaptados a las condiciones ambientales.

Modelling lifetime data with multivariate Tweedie distribution

Abstract: This study aims to measure the dependence between individual lifetimes by applying multivariate Tweedie distribution to the lifetime data. Dependence between lifetimes incorporated in the mortality model is a new form of idea that gives significant impact on the risk of the annuity portfolio which is actually against the idea of standard actuarial methods that assumes independent between lifetimes. Hence, this paper applies Tweedie family distribution to the portfolio of lifetimes to induce the dependence between lives. Tweedie distribution is chosen since it contains symmetric and non-symmetric, as well as light-tailed and heavy-tailed distributions. Parameter estimation is modified in order to fit the Tweedie distribution to the data. This procedure is developed by using method of moments. In addition, the comparison stage is made to check for the adequacy between the observed mortality and expected mortality. Finally, the importance of including systematic mortality risk in the model is justified by th...

Terrestrial laser scanners self-calibration study: Datum constraints analyses for network configurations

Abstract: Similar to other electronic instruments, terrestrial laser scanner (TLS) can also inherent with various systematic errors coming from different sources. Self-calibration technique is a method available to investigate these errors for TLS which were adopted from photogrammetry technique. According to the photogrammetry principle, the selection of datum constraints can cause different types of parameter correlations. However, the network configuration applied by TLS and photogrammetry calibrations are quite different, thus, this study has investigated the significant of photogrammetry datum constraints principle in TLS self-calibration. To ensure that the assessment is thorough, the datum constraints analyses were carried out using three variant network configurations: (1) minimum number of scan stations; (2) minimum number of surfaces for targets distribution; and (3) minimum number of point targets. Based on graphical and statistical, the analyses of datum constraints selection indicated that the parameter correlations obtained are significantly similar. In addition, the analysis has demonstrated that network configuration is a very crucial factor to reduce the correlation between the calculated parameters.