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Curie, Florence, Annabelle Mas, Julien Perret, Anne Puissant und Anne Ruas. „Simulation d’un processus de densification du tissu urbain à base d’agents“. Revue internationale de géomatique 21, Nr. 4 (30.12.2011): 489–511. http://dx.doi.org/10.3166/rig.15.489-511.
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Charness, Neil. „Psychological Models of Aging: How, Who, and What? A Comment“. Canadian Journal on Aging / La Revue canadienne du vieillissement 14, Nr. 1 (1995): 67–73. http://dx.doi.org/10.1017/s0714980800010503.
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RÉSUMÉSchroots soulève d'importantes questions ayant trait au processus du vieillissement, notamment «De quelle façon devrions-nous étudier le processus du vieillissement?», «Quelles personnes devrions-nous étudier?», et «Quel est le meilleur moyen d'établir les modèles de changement?». J'aborde ces questions en utilisant des analogies dans leur sens large, comme «gérodynamique» et entropie, et je défends une stratégie qui détermine des phénomènes de base pour fournir une explication et utilise la simulation par ordinateur pour modeler ces phénomènes.
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Lebl, Aleksandar, Dragan Mitić und Žarko Markov. „A role of Excel program in telecommunication processes simulation“. Scientific Technical Review 73, Nr. 1 (2023): 13–17. http://dx.doi.org/10.5937/str2301013l.
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This paper presents the simulation of mobile telephony systems realized in Excel program. Although primarily intended for other applications, Excel has several advantages over other specialized programs for simulation purposes. Excel application for simulation is illustrated by several examples from already published papers with the main goal to describe the most important part of realized simulations that allows determination of all important characteristics of telecommunication traffic process. Beside traffic process, the Excel application allows a reliable simulation of base station emission power starting from a random distance between the base station and mobile station.
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Lemogne, C. „L’imagerie cérébrale fonctionnelle : un outil au service de la psychopathologie ?“ European Psychiatry 30, S2 (November 2015): S3—S4. http://dx.doi.org/10.1016/j.eurpsy.2015.09.021.
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La psychopathologie est précieuse pour guider l’application de l’imagerie cérébrale fonctionnelle à l’étude des troubles mentaux. En permettant une approche basée sur les processus mentaux plutôt que sur des catégories diagnostiques (par ex. rumination plutôt que dépression), elle offre l’opportunité d’identifier des biomarqueurs susceptibles d’enrichir la nosographie psychiatrique et de renseigner les stratégies diagnostiques et thérapeutiques. En revanche, savoir si l’imagerie cérébrale fonctionnelle peut être un outil au service de la psychopathologie, c’est-à-dire de la compréhension des processus mentaux sous-jacents aux troubles psychiatriques, reste une question controversée. Un intérêt potentiel de l’imagerie cérébrale fonctionnelle pourrait être l’identification de processus mentaux non conscients et inaccessibles à une mesure comportementale. C’est ainsi que la constatation de bases cérébrales communes entre douleur morale et douleur physique a pu donner lieu à des spéculations fascinantes sur l’origine de leur parenté lexicale. Ou encore que certains envisagent de pouvoir distinguer conversion et simulation sur la base de l’activité cérébrale. Mais interpréter cette activité comme témoignant d’un processus mental, raisonnement appelé inférence inverse, pose plusieurs problèmes, que le processus mental soit rapportable ou non. Par exemple, l’activité cérébrale observée peut ne pas être pas spécifique du processus mental en question. Ou alors cette activité cérébrale peut ne pas être définie avec assez de précision. L’ensemble de ces problèmes peut être formalisé dans une perspective bayésienne. En dépit de ces limites, l’inférence inverse est néanmoins un outil heuristique puissant pour susciter des hypothèses secondairement réfutables concernant la nature des processus mentaux et leurs relations (par ex. évocation de l’objet perdu et renforcement lors d’un deuil compliqué). Combinée à des paradigmes expérimentaux de qualité, l’imagerie cérébrale fonctionnelle est donc susceptible d’apporter des connaissances nouvelles à la psychopathologie.
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Bursi, Fabio, Andrea Ferrara, Andrea Grassi und Chiara Ronzoni. „Simulating Continuous Time Production Flows in Food Industry by Means of Discrete Event Simulation“. International Journal of Food Engineering 11, Nr. 1 (01.02.2015): 139–50. http://dx.doi.org/10.1515/ijfe-2014-0002.
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Abstract The paper presents a new framework for carrying out simulations of continuous-time stochastic processes by exploiting a discrete event approach. The application scope of this work mainly refers to industrial production processes executed on a continuous flow of material (e.g. food and beverage industry) as well as production processes working on discrete units but characterized by a high speed flow (e.g. automated packaging lines). The proposed model, developed adopting the Discrete EVent system Specification (DEVS) formalism, defines a single generalized base unit able to represent, by means of an event scheme generated by state changes, the base behaviors needed for the modeling of a generic manufacturing unit, that is, (i) breakdowns and repairs, (ii) speed and accumulation, and (iii) throughput time. Moreover, the possibility to keep trace of additional measures of parameters related to the process and the flowing material (i.e. temperature, concentration of pollutant, and so on) is also considered. Since these parameters can change over time in a continuous manner, a specific discretization approach has been introduced to avoid the need to integrate parameter variation functions over time.
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Lin, Tzu-Shun, und Fang-Yi Cheng. „Impact of Soil Moisture Initialization and Soil Texture on Simulated Land–Atmosphere Interaction in Taiwan“. Journal of Hydrometeorology 17, Nr. 5 (14.04.2016): 1337–55. http://dx.doi.org/10.1175/jhm-d-15-0024.1.
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Abstract This study investigates the effect of soil moisture initializations and soil texture on the land surface hydrologic processes and its feedback on atmospheric fields in Taiwan. The simulations using the Weather Research and Forecasting (WRF) Model with the Noah land surface model were conducted for a 1-month period from 10 August to 12 September 2013 that included two typhoon-induced precipitation episodes and a series of clear-sky days. Soil moisture from the Global Land Data Assimilation System (GLDAS) was utilized to provide the soil moisture initialization process. In addition, updated soil textures based on field surveys in Taiwan were adopted for the WRF Model. Three WRF sensitivity runs were performed. The first simulation is the base case without any update (WRF-base), the second simulation utilizes GLDAS products to initialize the soil moisture (WRF-GLDAS), and the third simulation includes GLDAS products plus the updated soil textures and soil parameters (WRF-GSOIL). In WRF-base, the soil moisture initialization process is provided from National Centers for Environmental Prediction (NCEP) Final (FNL) Operational Global Analysis data, which are higher than the data from GLDAS products. The WRF-GLDAS and WRF-GSOIL with use of GLDAS data show lower soil moisture than WRF-base and agree better with observed data, while WRF-base shows a systematic wet bias of soil moisture throughout the simulation periods. In WRF-GSOIL, the soil textures with large-sized soil particles reveal higher soil conductivity; as a result, water drains through the soil column in a faster manner than the WRF-GLDAS, which leads to reduced soil moisture in western Taiwan. Among the three simulations, the variation of soil moisture is best simulated in WRF-GSOIL.
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Morrow, Jarrett D., und Brandon W. Higgs. „CallSim: Evaluation of Base Calls Using Sequencing Simulation“. ISRN Bioinformatics 2012 (12.12.2012): 1–10. http://dx.doi.org/10.5402/2012/371718.
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Accurate base calls generated from sequencing data are required for downstream biological interpretation, particularly in the case of rare variants. CallSim is a software application that provides evidence for the validity of base calls believed to be sequencing errors and it is applicable to Ion Torrent and 454 data. The algorithm processes a single read using a Monte Carlo approach to sequencing simulation, not dependent upon information from any other read in the data set. Three examples from general read correction, as well as from error-or-variant classification, demonstrate its effectiveness for a robust low-volume read processing base corrector. Specifically, correction of errors in Ion Torrent reads from a study involving mutations in multidrug resistant Staphylococcus aureus illustrates an ability to classify an erroneous homopolymer call. In addition, support for a rare variant in 454 data for a mixed viral population demonstrates “base rescue” capabilities. CallSim provides evidence regarding the validity of base calls in sequences produced by 454 or Ion Torrent systems and is intended for hands-on downstream processing analysis. These downstream efforts, although time consuming, are necessary steps for accurate identification of rare variants.
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Barton, G., X. Li und Gerhard Hirt. „Finite-Element Modeling of Multi-Pass Forging of Nickel-Base Alloys Using a Multi-Mesh Method“. Materials Science Forum 539-543 (März 2007): 2503–8. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.2503.
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Nickel-base alloys are mostly used for high-temperature applications, many of which are heavily loaded safety components. The material properties highly depend on the microstructure, which, in turn, depends on the metal forming process and the heat treatment. FEM integrated microstructure models can satisfactorily describe the grain size development due to dynamic and static recrystallisation during a metal forming processes and the heat treatment. The simulation results obtained from modeled compression experiments are very promising so that consequently, simulations of more sophisticated processes, like multi-pass open die forging or radial forging, is the next reasonable goal. However, the computation times for the simulation of these processes are still unsatisfactorily long and thus, their application is deterred. To accelerate the simulations, a multi-mesh algorithm was implemented to the Finite-Element simulation package PEP & LARSTRAN/SHAPE. This method uses a Finite-Element mesh that is fine in the deformation zone and coarse in the remaining areas of the workpiece. Due to the movement of the tools during the simulation, the deformation zone moves across the workpiece and thus, necessitates a remeshing with a transition of the finely meshed area. A second mesh, which is fine over the entire volume of the workpiece, is used to store the nodal data and simulation results, which get transferred to the simulation mesh every time a remeshing operation becomes necessary. In combination with an adopted data transfer algorithm, this second mesh is used to minimize the loss of accuracy, if a previously finely meshed area becomes a coarsely meshed area. This simulation model can be used to optimize forging process chains with respect to grain size distribution as well as cost effectiveness and energy consumption.
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Thews, O. „Simulation Analysis of the Influence of Hemodialysis Control Parameters on Exchange Processes during Therapy“. International Journal of Artificial Organs 15, Nr. 4 (April 1992): 213–21. http://dx.doi.org/10.1177/039139889201500405.
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The effect of dialysis control parameters (dialysate composition, ultrafiltration rate, blood flow rate) on the patient's internal milieu were studied using a mathematical model for the description of the dynamic exchange processes during hemodialysis. This model simulates the electrolyte and water distribution, the acid-base and the oxygenation state as well as the ventilation. The dialysate sodium concentration affects mainly the intra-/ extracellular water and the potassium distribution. The dialysate bicarbonate and acetate concentrations control the acid-base state and the electrolyte distribution (sodium and potassium). In addition, the dialysate acetate concentration has a strong effect on arterial oxygenation and on ventilation. The ultrafiltration rate controls the water distribution between plasma and the interstitial space but also the sodium distribution and the arterial acid-base state. The blood flow rate through the dialyser influences the acid-base state and, by this, it affects the potassium and sodium distribution. The acid-base state is affected in opposite directions when acetate or bicarbonate is used as a buffer.
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Zarin-Nejadan, Milad. „Fiscalité, q de Tobin et investissement privé en Suisse“. Recherches économiques de Louvain 58, Nr. 2 (1992): 213–35. http://dx.doi.org/10.1017/s0770451800083688.
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RésuméCette contribution a pour objet d’élaborer un modèle mettant en relation la variable q de Tobin corrigée pour la fiscalité avec le taux d’accumulation du capital dans le but d’évaluer l’effet de l’incitation fiscale sur l’investissement privé en Suisse. L’estimation du modèle sur la base des données portant sur la période d’après-guerre révèle le rô1e mineur joué par la fiscalité dans le processus d’investissement en Suisse. Par ailleurs, d’après les rèsultats de la simulation du modèle sous divers scénarios de réforme fiscale, les instruments fiscaux employés en Suisse, à savoir la manipulation du taux d’imposition des bénéfices et des taux de dépréciation fiscalement admis paraissent relativement inefficaces. Par contre, un instrument direct comme le crédit d’impôt, jamais encore utilisé, témoigne d’une assez grande efficacité.
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Anglada, Eva, Antton Meléndez, Laura Maestro und Ignacio Domínguez. „Finite Element Model Correlation of an Investment Casting Process“. Materials Science Forum 797 (Juni 2014): 105–10. http://dx.doi.org/10.4028/www.scientific.net/msf.797.105.
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The achievement of reliable simulations, in the case of complex processes as is the investment casting, is not a trivial task. Their accuracy is significantly related with the knowledge of the material properties and boundary conditions involved, but the estimation of these values usually is highly complex. One helpful option to try to avoid these difficulties is the use of inverse modelling techniques, where experimental temperature measurements are used as base to correlate the simulation models. The research presented hereafter corresponds to the correlation of a finite element model of the investment casting process of two nickel base superalloys, Hastelloy X and Inconel 718. The simulation model has been developed in a commercial software focused specifically on metal casting simulation. The experimental measurements used as base for the adjustment, have been performed at industrial facilities. The methodology employed combines the use of an automatic tool for model correlation with the manual adjustment guided by the researchers. Results obtained present a good agreement between simulation and experimental measurements, according to the industrial necessities. The model obtained is valid for the two studied cases with the only difference of the alloy material properties. The values obtained for the adjusted parameters in both cases are reasonable compared with bibliographic values. These two circumstances suggest that the obtained correlation is appropriate and no overfitting problems exist on it.
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Syuzev, V. V., E. V. Smirnova und A. V. Proletarsky. „Algorithms of multidimensional random process simulation“. Computer Optics 45, Nr. 4 (Juli 2021): 627–37. http://dx.doi.org/10.18287/2412-6179-co-770.
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The article discusses two approaches to modeling signals and processes: the method of filter construction and the trigonometric method. It is shown that the later approach is more promising, since an increase in the signal/process representation dimension mathematically means adding a term to the basis function formula, which gives access to fast simulation algorithms. Examples of algorithms for multidimensional simulation of random processes using two methods are given and a software system that implements these algorithms is described. The results provided by the software system will allow you to predict characteristics of engineering projects (accuracy and speed of modeling algorithms). Due to the high relevance of and need for fundamental research of methods and algorithms for digital transformation of the component base, the digitalization of all aspects of activity, including the synthesis of new materials, the development of new methods for designing micro- and nano-systems, the article aims to expand the scope of the spectral method of simulating multidimensional processes using original algorithmic complexes.
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Khudayarov, B. A., KH M. Komilova und F. ZH Turaev. „Numerical Simulation of Vibration of Composite Pipelines Conveying Pulsating Fluid“. International Journal of Applied Mechanics 11, Nr. 09 (November 2019): 1950090. http://dx.doi.org/10.1142/s175882511950090x.
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Vibration problems of pipelines made of composite materials conveying pulsating flow of gas and fluid are investigated in the paper. A dynamic model of motion of pipelines conveying pulsating fluid flow supported by a Hetenyi’s base is developed taking into account the viscosity properties of the structure material, axial forces, internal pressure and Winkler’s viscoelastic base. To describe the processes of viscoelastic material strain, the Boltzmann–Volterra integral model with weakly singular hereditary kernels is used. Using the Bubnov–Galerkin method, the problem is reduced to the study of a system of ordinary integro-differential equations (IDE). A computational algorithm is developed based on the elimination of the features of IDE with weakly singular kernels, followed by the use of quadrature formulas. The effect of rheological parameters of the pipeline material, flow rate and base parameters on the vibration of a viscoelastic pipeline conveying pulsating fluid is analyzed. The convergence analysis of the approximate solution of the Bubnov–Galerkin method is carried out. It was revealed that the viscosity parameters of the material and the pipeline base lead to a significant change in the critical flow rate. It was stated that an increase in excitation coefficient of pulsating flow and the parameter of internal pressure leads to a decrease in the critical flow rate. It is shown that an increase in the singularity parameter, the Winkler base parameter, the rigidity parameter of the continuous base layer and the Reynolds number increases the critical flow rate.
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Makhmanazarov, Ramdas, Ilya Tseplyaev, Sergey Shipilov und Natalya Krivova. „Estimation of SAR Average in Rats during 5G NR Chronic Exposure“. Applied Sciences 14, Nr. 1 (26.12.2023): 208. http://dx.doi.org/10.3390/app14010208.
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To study physiological reactions in the brain and skin of higher mammals exposed to chronic radiofrequency radiation, specific absorption ratio (SAR) determination is required and time-consuming numerical methods are used. The paper deals with the estimation of the whole-body specific absorption rate (SAR) in rats chronically exposed to external electromagnetic fields, as well as the development of a laboratory setup simulating the operation of a fifth-generation 5G New Radio base station (with a signal bandwidth of 15 MHz and a carrier frequency of 2.4 GHz). The paper presents a modified method for theoretical SAR estimation for one-sided irradiation and distributed absorption. Mean whole-body SAR values were estimated by the proposed method and numerically modeled with the CST Microwave Studio simulation software 2020package using primitive rat models. Dielectric parameters in the numerical simulation were used from the software library. The IEEE/IEC 62704-1 algorithm was used to investigate SAR in numerical simulations. The theoretical estimates and numerical simulations were compared for different SAR distributions and were found to be qualitatively comparable. The differences between approximate theoretical estimates and numerical simulations are 7% and 10% for distributed and non-distributed absorptions, respectively. The proposed method, which takes into account the decreasing power flux density, can be used to estimate the approximate whole-body SAR during chronic electromagnetic field exposure in rats.
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Moskalev, Dmitrii, Andrei Kozlov, Uliana Salgaeva, Victor Krishtop und Anatolii Volyntsev. „Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO3 Waveguides“. Applied Sciences 13, Nr. 11 (23.05.2023): 6374. http://dx.doi.org/10.3390/app13116374.
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Photonic integrated circuits (PIC) find applications in the fields of microwaves, telecoms and sensing. Generally, PICs are fabricated on a base of isotropic materials such as SOI, Si3N4, etc. However, for some applications, anisotropic substrates such as LiNbO3 are used. A thin film of LiNbO3 on an insulator (LNOI) is a promising material platform for complex high-speed PICs. The design and simulation of PICs on anisotropic materials should be performed using rigorous numerical methods based on Maxwell’s equations. These methods are characterized by long calculation times for one simulation iteration. Since a large number of simulation iterations are performed during the PIC design, simulation methods based on approximations should be used. The effective index method (EIM) is an approximation-based method and is widely applied for simulations of isotropic waveguides. In this study, the applicability of EIM for simulations of anisotropic waveguides is analyzed. The results obtained by EIM are compared with the calculation results of a rigorous finite-difference frequency-domain (FDFD) method for evaluation of the EIM’s applicability limits. In addition, radiation losses in waveguides with rough sidewalls are estimated using the Payne–Lacey model and EIM. The results demonstrate the applicability of EIM for the simulation of anisotropic LNOI-based waveguides with cross-section parameters specified in this paper.
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Breit, M., B. Pfeifer, C. Baumgartner, R. Modre-Osprian, B. Tilg und M. Visvanathan. „Systematic Analysis of Signaling Pathways Using an Integrative Environment“. Methods of Information in Medicine 46, Nr. 03 (2007): 386–91. http://dx.doi.org/10.1160/me0399.
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Summary Introduction: Understanding the biological processes of signaling pathways as a whole system requires an integrative software environment that has comprehensive capabilities. The environment should include tools for pathway design, visualization, simulation and a knowledge base concerning signaling pathways as one. In this paper we introduce a new integrative environment for the systematic analysis of signaling pathways. Methods: This system includes environments for pathway design, visualization, simulation and a knowledge base that combines biological and modeling information concerning signaling pathways that provides the basic understanding of the biological system, its structure and functioning. The system is designed with a client-server architecture. It contains a pathway designing environment and a simulation environment as upper layers with a relational knowledge base as the underlying layer. Results: The TNFα-mediated NF-κB signal transduction pathway model was designed and tested using our integrative framework. It was also useful to define the structure of the knowledge base. Sensitivity analysis of this specific pathway was performed providing simulation data. Then the model was extended showing promising initial results. Conclusion: The proposed system offers a holistic view of pathways containing biological and modeling data. It will help us to perform biological interpretation of the simulation results and thus contribute to a better understanding of the biological system for drug identification.
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Fortin, J. P., R. Moussa, C. Bocquillon und J. P. Villeneuve. „Hydrotel, un modèle hydrologique distribué pouvant bénéficier des données fournies par la télédétection et les systèmes d'information géographique“. Revue des sciences de l'eau 8, Nr. 1 (12.04.2005): 97–124. http://dx.doi.org/10.7202/705215ar.
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Les processus hydrologiques variant dans l'espace et dans le temps en fonction de la variabilité spatio-temporelle des entrées météorologiques et de l'occupation du sol ainsi que de la variabilité spatiale de la topographie et de la nature du terrain, un modèle conçu pour bénéficier des données provenant de la télédétection et des SIG a été développé. Les principaux objectifs poursuivis étaient: l'application au plus grand nombre de bassins possible, une sélection d'algorithmes permettant de tenir compte des données disponibles, un minimum d'étalonnage, la facilité de transfert d'un bassin à l'autre, la programmation des algorithmes sur micro-ordinateur avec une interface très conviviale. La structure d'écoulement à l'intérieur d'un bassin versant est obtenue de manière informatisée à partir d'une discrétisation des altitudes rencontrées dans la zone d'intérêt, en mailles carrées de dimensions données, d'où l'on tire les pentes et les orientations de chaque maille, puis le bassin versant en amont de la maille identifiée comme exutoire, le réseau hydrographique, les sous-bassins versants et, finalement, les unités hydrologiques relativement homogènes (UHRH), définies sur la base de ces sous-bassins, en les regroupant ou les divisant au besoin. Un logiciel spécifique pour ce faire a été développé: PHYSITEL. Selon la conception très modulaire adoptée pour HYDROTEL, chaque sous-modèle offre généralement plus d'une option de simulation, afin de tenir compte des données disponibles sur le bassin versant traité. Les simulations peuvent être réalisées en considérant comme unité de simulation du bilan hydrologique vertical les mailles originales constituant le bassin ou les UHRH. Des exemples de simulation des débits à l'aide du modèle HYDROTEL sur divers bassins versants situés au Canada (Québec, Ontario, Colombie-Britannique) et dans le sud de la France sont présentés. Ces simulations indiquent que les différents algorithmes du modèle réagissent bien et qu'il est possible de considérer son application sur des bassins très divers situés sous des conditions climatiques variées. Des tests plus poussés sont en cours afin de mieux cerner la sensibilité des divers algorithmes aux données d'entrée ainsi que leur interchangeabilité.
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Kloppenborg, Thomas, Marco Schikorra, Michael Schomäcker und A. Erman Tekkaya. „Numerical Optimization of Bearing Length in Composite Extrusion Processes“. Key Engineering Materials 367 (Februar 2008): 47–54. http://dx.doi.org/10.4028/www.scientific.net/kem.367.47.
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The decrease of the bearing length in extrusion processes results in increasing of the material flow and offers, through this, the possibility for manipulation and optimization. This paper presents a simulation based optimization technique which uses this effect for optimizing the material flow in direct extrusion processes. Firstly, the method is used in a multi-extrusion process with equal pitch circle profiles, then in an extrusion process of an asymmetric profile. Furthermore, a composite extrusion process is analyzed where endless wires of high strength steel are embedded in a base material of aluminum. The insertion of reinforcement elements into the base material flow, especially within the small ratio between profile thickness and the reinforcement diameter, can lead to significant local disturbances inside the die, which result in undesirable profile defects. Hence, the simulation-based optimization method is especially used to optimize inhomogeneous wall thicknesses in composite profiles.
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Bindu, M. D., P. S. Tide und A. B. Bhasi. „Numerical Studies on Temperature and Material Flow During Friction Stir Welding using Different Tool Pin Profiles“. Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 83, Nr. 1 (03.06.2021): 91–104. http://dx.doi.org/10.37934/arfmts.83.1.91104.
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A three dimensional computational fluid dynamics (CFD) model has been developed to study the effect of tool pin profile on the material flow and temperature development in friction stir welding (FSW) of high specific strength AA 7068 alloy. Numerical simulations were carried out using a RNG k-e turbulence model. Three tool pin profiles, viz. cylindrical, conical and straight cylindrical threaded were considered for the simulation. The temperature distribution and material flow pattern obtained from the simulation were compared for different pin profiles. Simulation results predicted Temperature distribution and material maxing was better in straight cylindrical tapered thread pin welds. Weld joints were fabricated using the straight cylindrical threaded pin with the same parametric combinations as in the simulation. Peak temperature measured in the experiment was less than that obtained by simulation. Hardness measurements taken at different weld regions has showed that about 71% of that of the base metal hardness is obtained with the threaded tool pin. The microstructure study revealed a defect free weld joint. Precipitates distributed in the microstructure indicate sufficient heat input to join the material without dissolving precipitates. The developed numerical model is helpful in optimising FSW process parameters.
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Caldwell, Peter, und Christopher S. Bretherton. „Large Eddy Simulation of the Diurnal Cycle in Southeast Pacific Stratocumulus“. Journal of the Atmospheric Sciences 66, Nr. 2 (01.02.2009): 432–49. http://dx.doi.org/10.1175/2008jas2785.1.
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Abstract This paper describes a series of 6-day large eddy simulations of a deep, sometimes drizzling stratocumulus-topped boundary layer based on forcings from the East Pacific Investigation of Climate (EPIC) 2001 field campaign. The base simulation was found to reproduce the observed mean boundary layer properties quite well. The diurnal cycle of liquid water path was also well captured, although good agreement appears to result partially from compensating errors in the diurnal cycles of cloud base and cloud top due to overentrainment around midday. At all times of the day, entrainment is found to be proportional to the vertically integrated buoyancy flux. Model stratification matches observations well; turbulence profiles suggest that the boundary layer is always at least somewhat decoupled. Model drizzle appears to be too sensitive to liquid water path and subcloud evaporation appears to be too weak. Removing the diurnal cycle of subsidence had little effect on simulated liquid water path. Simulations with changed droplet concentration and drizzle susceptibility showed large liquid water path differences at night, but differences were quite small at midday. Droplet concentration also had a significant impact on entrainment, primarily through droplet sedimentation feedback rather than through drizzle processes.
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Mazal, Jan, Jan Zezula, Josef Procházka und Dalibor Procházka. „The use of modeling and simulation in the development process optimization of the Armed Forces of the Czech Republic“. Vojenské rozhledy 31, Nr. 4 (01.12.2022): 140–58. http://dx.doi.org/10.3849/2336-2995.31.2022.04.140-158.
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The article contributes to a more efficient use of the theoretical, technological and application base, especially to the improvement of decision-making processes at the strategic level. It offers a methodological framework for solving the armed forces capability optimization problem by implementing modeling, simulation and operations research tools and theories.
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TALAMUCCI, F. „FREEZING PROCESSES IN SATURATED SOILS“. Mathematical Models and Methods in Applied Sciences 08, Nr. 01 (Februar 1998): 107–38. http://dx.doi.org/10.1142/s0218202598000068.
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When a soil saturated with water is subject to freezing, a volume expansion can generally be observed. The increase in volume is due not only to the different densities of water and ice, but mainly to a water migration process that is transported from the base of the soil up to an intermediate region where the change of phase occurs. It is generally accepted that a transition region, called frozen fringe, where ice and water coexist in the porous space, separates the unfrozen from the frozen part of the soil. Immediately over the frozen fringe a pure segregated layer of ice (ice lens) can form. If the freezing process is too fast or the weight acting on the soil (overburden pressure) is relevant, the porous matrix does not separate and the shifting of the frozen fringe towards the base of the soil (frost penetration) is observed. Many mathematical models have been proposed for the frost heave process. The main features of the one-dimensional model we are considering are summarized in Sec. 1. In Ref. 9 the case of assignment of the boundary thermal fluxes (at the base and on top of the soil) is studied. In practical cases, sometime the boundary temperatures, instead of the thermal fluxes, can be registered or imposed: in this paper we will investigate the model in such case. The main purpose is to detect which are the boundary values for temperature that determine the process of lens formation or frost penetration, once the properties of the soil are known.
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Verdete, Bogdan Marian, Corneliu Rontescu und Tudor George Alexandru. „Capturing the temperature gradients of GMAW hardfacing processes by employing CFD and FEM simulation procedures“. MATEC Web of Conferences 373 (2022): 00065. http://dx.doi.org/10.1051/matecconf/202237300065.
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Hardfacing is carried out whenever a local improvement of the mechanical properties of metallic parts is demanded. In this regard, gas metal arc welding technology is one of the most popular choices. One decisive factor of the welded joint quality is governed by the heat affected zone. The present paper proposes a simulation methodology that can be employed for capturing the temperature gradients in any location of the base metal, when such information is required. The model was developed by using ANSYS Workbench simulation software and is based on coupled CFD and Transient Thermal analysis. In the first stage, a welded sample is subjected to 3D scanning for recreating its constitutive surfaces in a CAD environment. In the next stage, the convective heat transfer occurring due to the velocity of the shielding gas is captured by means of CFD analysis. Experimentally derived temperatures are employed for developing a transient thermal analysis, having defined the exterior heat transfer coefficient. In the last stage, the simulation results are verified in an arbitrary location of the base metal that is located outside the heat affected zone.
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Herron, Jonathan B. T., Andrew Harbit und James A. T. Dunbar. „Subduing the killer - sepsis; through simulation“. BMJ Evidence-Based Medicine 24, Nr. 1 (27.07.2018): 26–29. http://dx.doi.org/10.1136/bmjebm-2018-110960.
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Few pathophysiological processes have a higher morbidity and mortality than sepsis. Implementing effective strategies to improve these poor outcomes remains a challenge. Previous work has shown improvements using single and multifaceted approaches, many with inclusion of sepsis training for doctors and nurses. However, previous work has not necessarily trained all those involved in the recognition and treatment of sepsis. After sepsis simulation training using cognitive-constructivist teaching methods, reaudit demonstrated highly significant improvement in ‘sepsis-six’ delivery. This study found inclusion of healthcare assistants in sepsis training is of great importance. This training should be tailored to personnel’s current knowledge base and level of experience.
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Ageenkov, E. V., A. A. Sitnikov und E. N. Vodneva. „Results of Mathematical Simulation of Transient Processes for the Sea Shelf Conditions“. Russian Geology and Geophysics 63, Nr. 7 (01.07.2022): 802–15. http://dx.doi.org/10.2113/rgg20204260.
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Abstract —Electrical exploration measurements in water areas and on land are carried out to study the electromagnetic (EM) properties of geological formations. A distinctive feature of aquatic electrical exploration is associated with the specific influence of a water column. Numerical calculations of the EM signal of the transient process for electrical lines in the axial region of the source under the conditions of marine waters with a depth of 50 to 250 m are presented in order to demonstrate how an induced polarization (IP) signal manifests itself in a transient process signal on different setups, to identify differences in the manifestation of galvanic induced polarization (GIP) and induction-induced polarization (IIP) in a transient process signal, and to substantiate these differences. The influence of the setup dimensions on the manifestation of IP during a transient process is studied by analyzing a change in the transient signal (ΔU(t)), the final difference of the transient process signal (Δ2U(t)) and transform P1(t) (ratio of these values) for a horizontal electrical setup with a source (AB) 50 to 2000 m in length, a three-electrode measuring line (M1M2M3) 50 to 2000 m in length, a distance between the source centers and the measuring line M1M3 (spacing, r) from 100 to 4000 m. Some of these parameters are used in differential-normalized electrical prospecting (DNME). The comparison of ΔU(t) and Δ2U(t) and their transforms in conducting and conducting-polarizable models under the same conditions is performed. The setup is placed on the surface and inside a conducting medium (a sea shelf water column) with a conducting polarizable base (geologic medium (ground) covered with a water layer). The polarizability of the base is taken into account by introducing a frequency-dependent resistivity using the Cole—Cole equation. It is shown by the calculations performed that the transient process components associated with the formation of an EM field and with GIP and IIP manifest themselves in dissimilar ways on differently sized setups at various depths. In a water area, IP manifests itself in two ways, being associated with both galvanic and eddy currents. In previous practical measurements, IIP was considered to be associated with interference, but this signal is simulated and can be regarded as information about IP. The factor influencing the IP manifestation in a transient process signal is a reduced setup height (hΔ), i.e., a distance between a setup and a sea bottom (polarizable base of the model) attributed to the AB line. Depending on the reduced setup height, the IP signal in transform P1(t) can manifest itself as an ascending branch at later times or appear as a descending branch passing into the negative values of P1. The pulse impact duration and the transient process measurements affect the contrasting manifestation of the polarizable base in the signal, but the measurements performed when the setup is being towed impose certain restrictions. The optimal parameters of the EM survey for IP studies should ensure a sufficient polarization range and the proper quality of measurements. The software used in the calculations was developed by OOO Sibirskaya Geofizicheskaya Nauchno-Proizvodstvennaya Kompaniya.
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Sweeder, Ryan D., Deborah G. Herrington und Jessica R. VandenPlas. „Supporting students’ conceptual understanding of kinetics using screencasts and simulations outside of the classroom“. Chemistry Education Research and Practice 20, Nr. 4 (2019): 685–98. http://dx.doi.org/10.1039/c9rp00008a.
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Simulations have changed chemistry education by allowing students to visualize the motion and interaction of particles underlying important chemical processes. With kinetics, such visualizations can illustrate how particles interact to yield successful reactions and how changes in concentration and temperature impact the number and success of individual collisions. This study examined how a simulation exploring particle collisions, or screencast employing the same simulation, used as an out-of-class introduction helped develop students’ conceptual understanding of kinetics. Students either manipulated the simulation themselves using guided instructions or watched a screencast in which an expert used the same simulation to complete an assignment. An iterative design approach and analysis of pretest and follow up questions suggests that students in both groups at two different institutions were able to achieve a common base level of success. Instructors can then build upon this common experience when instructing students on collision theory and kinetics. Eye-tracking studies indicate that the simulation and screencast groups engage with the curricular materials in different ways, which combined with student self-report data suggests that the screencast and simulation provide different levels of cognitive demand. This increased time on task suggests that the screencast may hold student interest longer than the simulation alone.
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Gai, Deng Yu, Yu Zhao Chu, Qing Fen Li und Qun Xia Li. „Process Optimization of Large Turbine Blade Casting Base on Numerical Simulation“. Applied Mechanics and Materials 16-19 (Oktober 2009): 535–39. http://dx.doi.org/10.4028/www.scientific.net/amm.16-19.535.
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3-D velocity and temperature fields of mold filling and solidification processes of large turbine blade casting were simulated. It indicated that the velocity field of upright casting is faster and steadier than lying casting. The deformation was predicted and the rule of deformation was reflected by analyzing stress field during solidification of upright casting. The casting processes were optimized, and then applied to produce castings.
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Zhang, Zekun, Yong Peng, Miao Zhang, Quanjun Yin und Qun Li. „An Approach for Deployment of Service-Oriented Simulation Run-Time Resources“. Applied Sciences 13, Nr. 20 (16.10.2023): 11341. http://dx.doi.org/10.3390/app132011341.
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The requirements for low latency and high stability in large-scale geo-distributed training simulations have made cloud-edge collaborative simulation an emerging trend. However, there is currently limited research on how to deploy simulation run-time resources (SRR), including edge servers, simulation services, and simulation members. On one hand, the deployment schemes of these resources are coupled and have mutual impacts. It is difficult to ensure overall optimum by deploying these resources separately. On the other hand, the pursuit of low latency and high system stability is often challenging to achieve simultaneously because high stability implies low server load, while a small number of simulation services implies high response latency. We formulate this problem as a multi-objective optimization problem for the joint deployment of SRR, considering the complex combinatorial relationship between simulation services. Our objective is to minimize the system time cost and resource usage rate of edge servers under constraints such as server resource capacity and the relationship between edge servers and base stations. To address this problem, we propose a learnable genetic algorithm for SRR deployment (LGASRD) where the population can learn from elites and adaptively select evolution operators performing well. Extensive experiments with different settings based on real-world data sets demonstrate that LGASRD outperforms the baseline policies in terms of optimality, feasibility, and convergence rate, verifying the effectiveness and excellence of LGASRD when deploying SRR.
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Zeng, Zhiping, Ji Hu, Xudong Huang, Weidong Wang, Zhibin Huang, Abdulmumin Ahmed Shuaibu, Yu Yuan, Zhonglin Xie und Xianfeng He. „Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load“. Applied Sciences 12, Nr. 3 (07.02.2022): 1694. http://dx.doi.org/10.3390/app12031694.
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To meet the transportation requirements of heavy-haul trains, it is necessary to consider the use of prestressed reinforced concrete ballastless tracks. Therefore, the CRTSIII SBT (China Railway Track System III-type slab ballastless track) has been considered for its convenient construction and geometric adjustment. Considering the problems existing in the base plate of CRTSIII SBT in heavy-haul applications, an indoor test and simulation were conducted to explore the cracking phenomenon of the base plate concrete under fatigue load. The reliability of the simulation was verified through the experimental results. A fatigue crack development law of the base plate structure was established. Furthermore, the influence of the load position, the thickness of self-compacting concrete and axle loads on the fatigue damage of the base plate structure were investigated. For the CRTSIII SBT subjected to heavier axle loads, it is appropriate to thicken the self-compacting concrete layer and strengthen the concrete and steel reinforcement at the plate end to reduce fatigue damage and cracks. The research results can serve as a basis for the optimization of the CRTSIII SBT base plate structure in heavy-haul railway applications.
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Baptista, António José, Dulce Maria Rodrigues und Luís Filipe Menezes. „Influence of the Weld on the Mechanical Behaviour of Tailor Welded Blanks“. Materials Science Forum 514-516 (Mai 2006): 1493–500. http://dx.doi.org/10.4028/www.scientific.net/msf.514-516.1493.
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In new car production, an innovative method to produce strong and light panels consists in applying Tailor Welded Blanks (TWBs) in the body-in-white base structure. Since the fusion welding processes can induce significant changes in the material properties of the base materials, an important question is whether the weld bead has a significant influence on the overall behaviour of the welded blanks. In this work, some preliminary conclusions on this subject were achieved based on results of the numerical simulation of simple mechanical tests: tensile, shear and simple bending. The numerical simulations were performed with a fully implicit finite element program (DD3IMP). The results obtained show that for a slight mismatch of properties between the weld and the base materials, no important influence of the weld in the TWBs behaviour is noticed. However, a significant strength reduction can be observed for strong undermatch conditions (lower mechanical properties in the weld) even when the weld bead is very narrow.
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Wang, Houzhi, You Wu, Jun Yang und Haopeng Wang. „Numerical Simulation on Reflective Cracking Behavior of Asphalt Pavement“. Applied Sciences 11, Nr. 17 (29.08.2021): 7990. http://dx.doi.org/10.3390/app11177990.
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Cracks are one of the main problems that plague road workers. A correct understanding of the internal crack propagation mechanism of asphalt pavement will help road workers evaluate the road’s working status more comprehensively and make more reasonable decisions in design, construction, and maintenance work. This paper established a three-dimensional asphalt pavement layered model using the software ABAQUS and fracture mechanics theory and the extended finite element method were used to explore the mechanical response of the pavement base layer’s preset reflective cracks. This paper investigated the influence of the modulus of each layer, vehicle load on the principal stress, shear stress, J-integral, and two stress intensity factors (K1, K2) during the predetermined crack propagation process of the pavement base layer, and the entropy method was used to analyze the above-mentioned mechanical response. The results show that the main factor affecting the propagation of reflective cracks on asphalt pavements is the modulus of the bottom surface layer. However, from a modeling perspective, the effect of increasing load on crack growth is obvious. Therefore, in terms of technical feasibility, the prevention of reflective cracks should still be achieved by controlling the driving load and prohibiting overloading.
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Naumov, Vitalii, Ievhen Nagornyi und Yana Litvinova. „Model of multimodal transport node functioning“. Archives of Transport 36, Nr. 4 (31.12.2015): 43–54. http://dx.doi.org/10.5604/08669546.1185202.
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To increase the efficiency of transport nodes functioning taking into account the logistics management principles it is necessary to optimize the structure and capacity of transport nodes' production resources, and to develop such a method for calculating of joint schedules for vehicles and freight hubs of the transport node, which takes into account stochastic nature of the parameters of material and informational flows. For solving the problems of optimal management of transport nodes functioning processes it is proposed to use the specific efficiency indicator, which is determined as a ratio of total costs of clients servicing in transport node to the costs of production resources used while servicing. According to the used approach for formalization of the transport node internal processes, development of the simulation model was implemented on the base of object-oriented programming principles. TransportNode.dll class library has been used as basic tool for simulations. The model implemented on the base of the library allows to take into account stochastic nature of demand and probabilistic nature of technological processes in transport nodes. Some results of numeric simulations for the loading area “Amur-Gavan” of Dnipropetrovsk River Port have been described in the paper.
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Cazelles, B., und D. Fontvieille. „Modélisation d'un système lotique pollué par une charge organique : prise en compte de l'activité des microorganismes benthiques“. Revue des sciences de l'eau 2, Nr. 4 (12.04.2005): 511–41. http://dx.doi.org/10.7202/705041ar.
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Les études entreprises depuis 1982 sur un petit cours d'eau pollué par une forte charge organique, ont servi de base au développement d'un modèle mathématique destiné à appréhender le fonctionnement des mécanismes d'auto-épuration. L'écriture du modèle a débuté par la description de l'écoulement du cours d'eau et des mécanismes de transports associés. Deux sous-modèles ont été utilisés dans ce but : un sous-modèle hydrodynamique dérivé du modèle de Saint-Venant et un sous-modèle de transport, constitué par l'équation classique de convection-dispersion. Ces deux sous-modèles sont appliqués à un écoulement monodimensionnel, non uniforme et non stationnaire. Dans les petits cours d'eau le compartiment benthique joue un rôle prépondérant du point de vue de l'ensemble des processus détritiques. Le modèle a donc été appliqué, dans un premier temps, à la simulation de la dynamique du carbone organique dissous et des microorganismes benthiques. Les mécanismes de biodégradation sont modélisés, ici, en utilisant l'analogie entre les processus détritiques et l'activité des biomasses des procédés de traitement des eaux usées. Le modèle de biofilm développé permet, par sa structure, d'englober tous les mécanismes physiques et biologiques qui entrent dans les phénomènes de disparition et de dégradation de la matière organique dissoute. Ce modèle est utilisé, sous sa forme actuelle, en tant qu'outil cognitif destiné à accroître la connaissance des mécanismes d'auto-épuration de la matière organique dissoute dans les petits cours d'eau.
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Bondarenko, Iryna, Alessandro Severino, Isaac Oyeyemi Olayode, Tiziana Campisi und Larysa Neduzha. „Dynamic Sustainable Processes Simulation to Study Transport Object Efficiency“. Infrastructures 7, Nr. 9 (19.09.2022): 124. http://dx.doi.org/10.3390/infrastructures7090124.
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The development of reliability theory has led to the setting of tasks requiring consideration of the efficiency and functional safety of technical objects of transport over the life cycle. The paper demonstrates the possibility of using the universal laws of elastic wave theory to describe natural phenomena occurring in complex dynamic systems, on the examples of solving issues arising in the interaction of rolling stock and the railway track. The accounting of the time component and the ability of elastic waves to propagate energy in time and space allowed considering any interaction process as a chain of processes, incidence-reflection-refraction of force impulses of interaction. Understanding the physics of dynamic processes that occur in objects while performing their intended functions allows developers to improve objects in such a way as to minimize their life cycle cost and maximize their ability to perform their intended functions under different operating conditions. In addition, it allows the expansion of existing methods and approaches to diagnostics of dynamic transport systems. All this is a base for making it possible to develop an innovative and effective tool for engineers and scientists to assess the impact of technosphere transport objects on human habitats.
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Panferov, Anatolii Dmitrievich, und Alexey Vladimirovich Makhankov. „Simulation of the effect of short optical pulses on graphene“. Program Systems: Theory and Applications 10, Nr. 1 (2019): 47–58. http://dx.doi.org/10.25209/2079-3316-2019-10-1-47-58.
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The interaction of high-frequency pulsed electric fields with graphene is currently the subject of intense research. The paper presents the results of testing a software system for modeling such processes using the example of ultrashort laser pulses of the optical range with different polarizations. The authors develop the system on a base of a new theoretical approach based on the quantum kinetic equation. The approach contains a computational model for a new system of ordinary differential equations with non-linearly dependent on time and problem parameters coefficients. The need to analyze the behavior of solutions of this system of equations in the field of changing several parameters leads to the polynomial computational complexity. The lack of knowledge of the nature of the parametric dependence of solutions requires several iterations of the choice of covering grids. The paper describes the adaptation of this modeling system for use in massively parallel computing systems.
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Godzhaev, Zakhid, Sergey Senkevich, Ivan Malakhov und Sergey Uyutov. „Development of a mathematical model of the oscillatory system of agricultural mobile power equipment with attachments for the creation of their adaptive springing systems“. E3S Web of Conferences 413 (2023): 02042. http://dx.doi.org/10.1051/e3sconf/202341302042.
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A mathematical model of oscillations of a mobile energy means (MEM) is presented and investigated. The proposed MEM oscillation model makes it possible to determine the positions of the MEM center of mass points in various situations on a support base (agrophone) with a different microprofile. Differential equations have been compiled for computer simulation. The solution of differential equations describing the oscillations of the MEM during its movement in a compound with attachments, as well as a computational experiment-simulation modeling were performed in the software complexes Mathcad and MATLAB Simulink. The initial data used are the mass-dimensional and elastic-damping properties of the structural elements of the MEM, based on the TK-3-180 tractor, obtained by calculation and experiment and a real support base (agrophone) with a known micro- and macro profile. The model makes it possible to study the dynamic processes of the oscillatory system “Support base (agrophone) – running system – machine frame with attachments – cab”. The results of computer simulation modeling are presented – graphs showing fluctuations of sprung and unsprung masses of MEM when moving on different backgrounds.
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Berroug, Fatiha, El Khadir Lakhal, Mohamed El Omari und Hamid El Qarnia. „Simulation numérique des besoins énergétiques d’une serre agricole sous le climat de Marrakech - Maroc“. Journal of Renewable Energies 13, Nr. 1 (25.10.2023): 133–48. http://dx.doi.org/10.54966/jreen.v13i1.184.
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Dans ce travail, on présente un modèle du bilan énergétique d’une serre agricole basé sur un ensemble d’équations théoriques intégrant les processus d’échanges thermiques entre les différentes composantes de la serre en tenant compte du couvert végétal. Le modèle ainsi développé prend en considération les conditions météorologiques instantanées du lieu de plantation de la serre (température, humidité, radiations solaires, vitesse du vent). Le système d’équations non linéaires obtenu est résolu par la méthode itérative de Newton-Raphson. Elle permet de prédire les paramètres climatiques suivants: la température de la plante, l’humidité et la température de l’air intérieur de la serre et les flux de chaleur sensible et latente des plantes. Pour une température de consigne exigée par la plante et dans le but d’estimer instantanément les besoins énergétiques de la serre (chauffage/refroidissement), le modèle a été inversé numériquement. Afin d’obtenir une évaluation des besoins en chauffage des serres à l’échelle régionale de Marrakech, pour une base de temps adéquate (période hivernale), une simulation dynamique a été conduite pour mieux gérer les apports énergétiques et les calendriers culturaux de la zone. Dans le cadre de ce travail, une quantification des différentes composantes des pertes thermiques à travers la structure d’une serre en plastique pour un débit d’énergie de chauffage donné a été réalisée. Pour minimiser les dépenses énergétiques, des mesures doivent être prises comme l’utilisation d’une double couverture en plastique, l’amélioration de l’étanchéité de la serre et l’installation d’un système de stockage d’énergie diurne pour une éventuelle restitution nocturne.
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Gaidzhurov, P. P., N. A. Saveleva und E. V. Trufanova. „Numerical simulation of the behavior of kinematically unstable slopes under dynamic influences“. Advanced Engineering Research 21, Nr. 4 (09.01.2022): 300–307. http://dx.doi.org/10.23947/2687-1653-2021-21-4-300-307.
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Introduction. The concept of estimating the dynamic parameters of the “base — weakened layer — block” system is proposed, taking into account the physical nonlinearity of the material and the kinematic method of excitation of vibrations. In accordance with this approach, the physical nonlinearity of the base and block material is considered using the Drucker- Prager model. The weakened layer is modeled by 3D spring finite elements. The verification procedure of the proposed methodology is carried out on the example of the dynamic calculation of the “base — weakened layer — slope” system.Materials and Methods. The computational experiments were performed using the ANSYS Mechanical software package in combination with a nonlinear solver based on the Newton-Raphson procedure. SOLID45 volumetric finite elements were used to discretize the computational domains. Combined elastic-viscous elements COMBIN14 were used to simulate the displacement of the block relative to the fixed base.Results. An engineering technique for the dynamic analysis of the stress-strain state of the “base — weakened layer — block” spatial system with kinematic method of excitation of vibrations is developed. The accuracy and convergence of the proposed method is investigated using specific numerical examples.Discussion and Conclusion. Based on the mathematic simulation performed, it is shown that the developed technique provides assessing the risks of the occurrence of real landslide processes caused by external non-stationary impacts.
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NIZAMUTDINOV, M. M., und V. V. ORESHNIKOV. „MODELING OF ADAPTIVE BEHAVIOR PROPERTIES OF PARTICIPANTS OF SOCIO-ECONOMIC PROCESSES“. Izvestia Ufimskogo Nauchnogo Tsentra RAN, Nr. 3 (30.09.2021): 55–60. http://dx.doi.org/10.31040/2222-8349-2021-0-3-55-60.
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The article deals with the issues of modeling socio-economic systems at the regional level. A promising direction in this area is the use of an agent-based approach based on taking into account the features and a certain autonomy of the behavior of interacting agents. Moreover, one of their key properties is the ability to adapt to changing conditions of functioning. Proceeding from this, in order to solve the problems of increasing the efficiency of developing strategic decisions, it is necessary to develop tools to support management decisions, which will be based on the use of an adaptive simulation model of the region. To do this, the article provides a brief overview of the types of agents depending on the methods of processing and using the information they perceive, an algorithm for the functioning of the agent within the framework of the simulation model is presented. It is shown that the information received by the agent can be of different nature. Separate characteristics of any objects, phenomena form a database. The collection of such information forms a precedent. A set of precedents form a rule base. The analysis showed that the adaptability of the agent's behavior is becoming an essential condition for the implementation of his goals. It should be noted that the agent acts in conditions of incomplete information, and his actions are largely described by the theory of bounded rationality. The structure of perceived information is shown and an approach to reflecting the adaptive properties of an agent through the learning subsystem is proposed. Its elements and implementation options are highlighted. From the point of view of reflecting the adaptive properties of the agent, obtaining new information leads to the replenishment of the database and the base of use cases. At the same time, within the framework of analytical activities, new information is compared with the expectations formed on the basis of previously available data and reflected in the agent's rule base. If the information received is contrary to the existing rules, then this becomes the starting point for their revision. Thus, the adaptation of the agent within the framework of the developed simulation model of the region is based on the adjustment of the rule base.
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Abe, S., J. H. Adams, D. Allard, P. Alldredge, R. Aloisio, L. Anchordoqui, A. Anzalone et al. „EUSO-Offline: A comprehensive simulation and analysis framework“. Journal of Instrumentation 19, Nr. 01 (01.01.2024): P01007. http://dx.doi.org/10.1088/1748-0221/19/01/p01007.
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Abstract The complexity of modern cosmic ray observatories and the rich data sets they capture often require a sophisticated software framework to support the simulation of physical processes, detector response, as well as reconstruction and analysis of real and simulated data. Here we present the EUSO-Offline framework. The code base was originally developed by the Pierre Auger Collaboration, and portions of it have been adopted by other collaborations to suit their needs. We have extended this software to fulfill the requirements of Ultra-High Energy Cosmic Ray detectors and very high energy neutrino detectors developed for the Joint Exploratory Missions for an Extreme Universe Observatory (JEM-EUSO). These path-finder instruments constitute a program to chart the path to a future space-based mission like POEMMA. For completeness, we describe the overall structure of the framework developed by the Auger collaboration and continue with a description of the JEM-EUSO simulation and reconstruction capabilities. The framework is written predominantly in modern C++ (compliled against C++17) and incorporates third-party libraries chosen based on functionality and our best judgment regarding support and longevity. Modularity is a central notion in the framework design, a requirement for large collaborations in which many individuals contribute to a common code base and often want to compare different approaches to a given problem. For the same reason, the framework is designed to be highly configurable, which allows us to contend with a variety of JEM-EUSO missions and observation scenarios. We also discuss how we incorporate broad, industry-standard testing coverage which is necessary to ensure quality and maintainability of a relatively large code base, and the tools we employ to support a multitude of computing platforms and enable fast, reliable installation of external packages. Finally, we provide a few examples of simulation and reconstruction applications using EUSO-Offline.
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Li, Xin, Zhi Xiong Zhang, Jian Zhong Shang und Yu Jun Cao. „Research on Angular Variation for Aeroplane-Assembly Base on State Space Model“. Applied Mechanics and Materials 278-280 (Januar 2013): 149–54. http://dx.doi.org/10.4028/www.scientific.net/amm.278-280.149.
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Abstract. Variation modeling is one of the most significant tools for assembly variation analysis. Considering dimension and geometric errors, and part situation errors, the error source that affects assembly accuracy is classified into two types: error of geometric location and orientation, error of geometric form. And unify these different types of error or deviation by the concept of Virtual Fixture. So a rigid assembly state space model is developed for stream of variation analysis in multi-station assembly processes. And an aeroplane-cabin-assembly process is analyzed in this model. The developed methodology outperforms the current simulation based techniques in computation efficiency, the model is validated using Monte Carlo series Simulations.
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Caparros-Mancera, Julio Jose, Cesar Antonio Rodríguez, Ángel Mariano Rodríguez-Pérez und Jose Antonio Hernández-Torres. „MODELING AND SIMULATION OF INDUSTRIAL PROCESSES = Modelado y simulación de procesos industriales“. Advances in Building Education 8, Nr. 1 (09.05.2024): 46–60. http://dx.doi.org/10.20868/abe.2024.1.5233.
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Este artículo presenta una metodología didáctica aplicada a los estudios de ingeniería. A partir del uso de herramientas digitales se desarrolla una metodología para modelar y simular un proceso de fabricación industrial. La metodología comienza con el análisis del proceso de fabricación, por lo que los estudiantes realizan una aproximación analítica al modelado del sistema productivo analizado. A continuación, se utiliza una herramienta digital para modelar dicho sistema en base a los parámetros previamente analizados. Con la simulación del modelo, los estudiantes de ingeniería analizan los resultados de tiempos y costes específicos de cada proceso y producto. En base a estos se presentan propuestas de mejora para optimizar el proceso que se modela y simula nuevamente para comprobar la eficiencia y beneficio de las mejoras propuestas en el proceso. Con esta metodología, los estudiantes de ingeniería se introducen en un contexto escalable de la industria real para realizar mejoras seguras, al mismo tiempo que desarrollan habilidades en ingeniería de procesos y herramientas digitales.AbstractThis paper presents a didactic methodology applied to engineering studies. From the use of digital tools, a methodology is developed to model and simulate an industrial manufacturing process. The methodology begins with the analysis of the manufacturing process, so the students carry out an analytical approach to the modeling of the analyzed production system. Next, a digital tool is used to model said system based on the previously analyzed parameters. With the simulation of the model, engineering students analyze the results of specific times and costs of each process and product. Based on these, improvement proposal are presented to optimize the process that are modelling and simulated again to check the efficiency and benefit of the proposed improvements in the process. With this methodology, engineering students are introduced to a scalable context of real industry for safe improvements, while developing skills in digital tools and processes engineering.
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Deng, Liang, Sergej Mozgovoy, Jens Hardell, Braham Prakash und Mats Oldenburg. „Implementation of Wear Models for Stamping Tools under Press Hardening Conditions Based on Laboratory Tests“. Advanced Materials Research 1063 (Dezember 2014): 339–42. http://dx.doi.org/10.4028/www.scientific.net/amr.1063.339.
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Tool wear occurring in press hardening processes receives insufficient attention since its corresponding measurements and full-scale experiments are complicated and expensive. This paper presents a study of tool wear in press hardening based on laboratory experiments and FE-simulations. Two experimental laboratory setups depending on the contact conditions in press hardening build the base for the wear models implemented in the FE-simulation to predict wear depths. The highest wear depth is found at the radius of the stamping tool and the discrepancies in wear predictions based on the two different laboratory test setups are analyzed.
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Shi, Hong Yan, Ming Zhe Yuan und Tian Ran Wang. „Design of Biodiesel Production Processes by Base-Catalyzed Transesterification“. Advanced Materials Research 512-515 (Mai 2012): 510–14. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.510.
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A lot of efforts have been carried out to develop an alternative fuel for the current energy and environment questions. Biodiesel which is synthesized by transesterification of plant oils and animal fat is a real alternative fuel for its renewable and lower emissions. Currently, biodiesel production by the base-catalyzed transesterification of the vegetable oil and methanol is widely utilized in the world. This paper studies the design of biodiesel production with the glycerol phase separation processes, through installing a decanter between reactors and adding methanol and NaOH batch optimization operation to improve the biodiesel yield and the conversion rate of reactants. Simulation results show that biodiesel yield increased by 9.79% and triglyceride conversion rate increased by 6.99%.
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MAKINOUCHI, Akitake. „S201 VCAD system : a base for integrating modeling and simulation of multiple processes“. Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2008.21 (2009): 337–38. http://dx.doi.org/10.1299/jsmebio.2008.21.337.
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Buršík, Jiří. „Atomistic simulation of processes in Ni-base alloys with account for local relaxations“. Materials Science and Engineering: A 462, Nr. 1-2 (Juli 2007): 149–52. http://dx.doi.org/10.1016/j.msea.2006.02.457.
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Dawood, Nashwan, Eknarin Sriprasert, Zaki Mallasi und Brian Hobbs. „Development of an integrated information resource base for 4D/VR construction processes simulation“. Automation in Construction 12, Nr. 2 (März 2003): 123–31. http://dx.doi.org/10.1016/s0926-5805(02)00045-6.
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Cha, Woon-Yong, Se-Bin Im, Jae-Won Kim und Dae-Gwan Kang. „The Simulation of the Dynamic Characteristics of Friction Stir Welding and the Structural Deflection of Base Materials“. Applied Sciences 12, Nr. 19 (30.09.2022): 9847. http://dx.doi.org/10.3390/app12199847.
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Friction stir welding requires an optimized process because the quality of the weld can vary depending on the dynamic characteristics of the welding tool. In addition, controlling the structural deflection of the base material according to the load of the welding tool is important. In this study, the structural deflection of thin base material according to the dynamic characteristics of the welding tool was confirmed using dynamic simulation. The generated deflection was controlled through the fixing clamp, and the results according to the rotation and progress speed of the welding tool were compared and analyzed through finite volume analysis. Thus, factors of the welding tools were obtained based on computational data without accompanying experimental data, and a process guide for efficient friction stir welding for thin base materials was presented.
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Wang, Qiang, Qi Shu, Alexandra Bozec, Eric P. Chassignet, Pier Giuseppe Fogli, Baylor Fox-Kemper, Andy McC Hogg et al. „Impact of increased resolution on Arctic Ocean simulations in Ocean Model Intercomparison Project phase 2 (OMIP-2)“. Geoscientific Model Development 17, Nr. 1 (15.01.2024): 347–79. http://dx.doi.org/10.5194/gmd-17-347-2024.
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Abstract. This study evaluates the impact of increasing resolution on Arctic Ocean simulations using five pairs of matched low- and high-resolution models within the OMIP-2 (Ocean Model Intercomparison Project phase 2) framework. The primary objective is to assess whether a higher resolution can mitigate typical biases in low-resolution models and improve the representation of key climate-relevant variables. We reveal that increasing the horizontal resolution contributes to a reduction in biases in mean temperature and salinity and improves the simulation of the Atlantic water layer and its decadal warming events. A higher resolution also leads to better agreement with observed surface mixed-layer depth, cold halocline base depth and Arctic gateway transports in the Fram and Davis straits. However, the simulation of the mean state and temporal changes in Arctic freshwater content does not show improvement with increased resolution. Not all models achieve improvements for all analyzed ocean variables when spatial resolution is increased so it is crucial to recognize that model numerics and parameterizations also play an important role in faithful simulations. Overall, a higher resolution shows promise in improving the simulation of key Arctic Ocean features and processes, but efforts in model development are required to achieve more accurate representations across all climate-relevant variables.
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Ridout, James A., Yi Jin und Chi-Sann Liou. „A Cloud-Base Quasi-Balance Constraint for Parameterized Convection: Application to the Kain–Fritsch Cumulus Scheme“. Monthly Weather Review 133, Nr. 11 (01.11.2005): 3315–34. http://dx.doi.org/10.1175/mwr3034.1.
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Abstract A quasi balance with respect to parcel buoyancy at cloud base between destabilizing processes and convection is imposed as a constraint on convective cloud-base mass flux in a modified version of the Kain–Fritsch cumulus parameterization. Supporting evidence is presented for this treatment, showing a cloud-base quasi balance (CBQ) on a time scale of approximately 1–3 h in explicit simulations of deep convection over the U.S. Great Plains and over the tropical Pacific Ocean with the Naval Research Laboratory’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS).1 With the exception of the smaller of two convective events in the Great Plains simulation, a CBQ is still observed upon restriction of the data analysis to instances where the available buoyant energy (ABE) exceeds a threshold value of 1000 J kg−1. This observation is consistent with the view that feedbacks between convection and cloud-base parcel buoyancy can control the rate of convection on shorter time scales than those associated with the elimination of buoyant energy and supports the addition of a CBQ constraint to the Kain–Fritsch mass-flux closure. Tests of the modified Kain–Fritsch scheme in single-column-model simulations based on the explicit three-dimensional simulations show a significant improvement in the representation of the main convective episodes, with a greater amount of convective rainfall. The performance of the scheme in COAMPS precipitation forecast experiments over the continental United States is also investigated. Improvements are obtained with the modified scheme in skill scores for middle to high rainfall rates.