Academic literature on the topic 'Multi-scale experimental approach'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Multi-scale experimental approach.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Multi-scale experimental approach"
1
Trélat, Sophie, and Michel-Olivier Sturtzer. "Predicting explosion and blast effects: A multi-scale experimental approach." International Journal of Safety and Security Engineering 9, no. 3 (November 30, 2019): 356–70. http://dx.doi.org/10.2495/safe-v9-n4-356-370.
Full text
2
Rots, Jan G., Francesco Messali, Rita Esposito, Valentina Mariani, and Samira Jafari. "Multi-Scale Approach towards Groningen Masonry and Induced Seismicity." Key Engineering Materials 747 (July 2017): 653–61. http://dx.doi.org/10.4028/www.scientific.net/kem.747.653.
Full textAbstract:
In the last years, the induced seismicity in the northern part of the Netherlands has considerably increased. The existing building stock was not designed for seismic loading, and it is characterised by very slender walls, limited cooperation between walls and floors, and use of cavity walls. As a consequence, the validation of analytical and numerical models for the assessment of unreinforced masonry buildings and the characterisation of the masonry at both material and structural level have become of great importance. An extensive large-scale testing program was performed at the Delft University of Technology in 2015 to create benchmarks for the validation of the numerical and analytical models. The attention was mainly devoted to a terraced house typology, which was widely adopted for housing in the period 1960-1980, and focused on the characterisation of the typology at various levels: material, connection, component and assemblage level. The experimental tests at component and assemblage levels were also reproduced by nonlinear finite element analysis, validated and calibrated against the data available from the testing campaign at material level. In this paper, an overview description of performed experiments and numerical analyses is provided; specific devotion is given to the main outcomes of the campaign and to the lessons learned by the experimental evidences for improving the numerical models.
3
Jia, Yonghong, Mingting Zhou, and Ye Jinshan. "OBJECT-ORIENTED CHANGE DETECTION BASED ON MULTI-SCALE APPROACH." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B7 (June 21, 2016): 517–22. http://dx.doi.org/10.5194/isprsarchives-xli-b7-517-2016.
Full textAbstract:
The change detection of remote sensing images means analysing the change information quantitatively and recognizing the change types of the surface coverage data in different time phases. With the appearance of high resolution remote sensing image, object-oriented change detection method arises at this historic moment. In this paper, we research multi-scale approach for high resolution images, which includes multi-scale segmentation, multi-scale feature selection and multi-scale classification. Experimental results show that this method has a stronger advantage than the traditional single-scale method of high resolution remote sensing image change detection.
4
Jia, Yonghong, Mingting Zhou, and Ye Jinshan. "OBJECT-ORIENTED CHANGE DETECTION BASED ON MULTI-SCALE APPROACH." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B7 (June 21, 2016): 517–22. http://dx.doi.org/10.5194/isprs-archives-xli-b7-517-2016.
Full textAbstract:
The change detection of remote sensing images means analysing the change information quantitatively and recognizing the change types of the surface coverage data in different time phases. With the appearance of high resolution remote sensing image, object-oriented change detection method arises at this historic moment. In this paper, we research multi-scale approach for high resolution images, which includes multi-scale segmentation, multi-scale feature selection and multi-scale classification. Experimental results show that this method has a stronger advantage than the traditional single-scale method of high resolution remote sensing image change detection.
5
Cai, Lei, and Shuiwang Ji. "A Multi-Scale Approach for Graph Link Prediction." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 04 (April 3, 2020): 3308–15. http://dx.doi.org/10.1609/aaai.v34i04.5731.
Full textAbstract:
Deep models can be made scale-invariant when trained with multi-scale information. Images can be easily made multi-scale, given their grid-like structures. Extending this to generic graphs poses major challenges. For example, in link prediction tasks, inputs are represented as graphs consisting of nodes and edges. Currently, the state-of-the-art model for link prediction uses supervised heuristic learning, which learns graph structure features centered on two target nodes. It then learns graph neural networks to predict the existence of links based on graph structure features. Thus, the performance of link prediction models highly depends on graph structure features. In this work, we propose a novel node aggregation method that can transform the enclosing subgraph into different scales and preserve the relationship between two target nodes for link prediction. A theory for analyzing the information loss during the re-scaling procedure is also provided. Graphs in different scales can provide scale-invariant information, which enables graph neural networks to learn invariant features and improve link prediction performance. Our experimental results on 14 datasets from different areas demonstrate that our proposed method outperforms the state-of-the-art methods by employing multi-scale graphs without additional parameters.
6
Mastropasqua, Luca, Alessandro Donazzi, and Stefano Campanari. "A Multi-Scale Modelling Approach and Experimental Calibration Applied to Commercial SOFCs." ECS Transactions 78, no. 1 (May 30, 2017): 2645–58. http://dx.doi.org/10.1149/07801.2645ecst.
Full text
7
Lo Monte, Francesco, Roberto Felicetti, Alberto Meda, and Anna Bortolussi. "Assessment of concrete sensitivity to fire spalling: A multi-scale experimental approach." Construction and Building Materials 212 (July 2019): 476–85. http://dx.doi.org/10.1016/j.conbuildmat.2019.03.332.
Full text
8
Leighton, M., T. Nicholls, M. De la Cruz, R. Rahmani, and H. Rahnejat. "Combined lubricant–surface system perspective: Multi-scale numerical–experimental investigation." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 231, no. 7 (December 12, 2016): 910–24. http://dx.doi.org/10.1177/1350650116683784.
Full textAbstract:
Frictional losses are one of the main causes of reduced energy efficiency in all machines and mechanisms. In particular, there is mounting pressure upon manufacturers of all forms of vehicle to comply with increasingly stringent legislation and directives with regard to harmful emissions. Therefore, reduction of friction has become an imperative issue. The traditional approach of dealing with surface material and lubricant formulation in isolation has been replaced by a lubricant–surface system approach. This paper presents multi-scale experimentation from nano/meso-scale lateral force microscopy of ultra-thin surface adsorbed films through to micro-scale precision sliding tribometry to investigate lubricant–surface friction optimisation within the mixed regime of lubrication, using lubricants with different organic and inorganic friction modifying species. These affect the parameters of the system, commonly used as input to models for mixed and boundary regimes of lubrication. Therefore, the precise measurement of these parameters at different physical scales is important. The study also makes use of detailed numerical predictions at micro-scale through combined solution of the average Reynolds equation as well as interaction of wetted asperities in mixed and boundary regimes of lubrication. Good agreement is found between the predictions and measurements at micro-scale tribometric interactions. Furthermore, the same trends are observed in testing across the physical scales.
9
Castro-Triguero, Rafael, Enrique Garcia-Macias, Erick Saavedra Flores, M. I. Friswell, and Rafael Gallego. "Multi-scale model updating of a timber footbridge using experimental vibration data." Engineering Computations 34, no. 3 (May 2, 2017): 754–80. http://dx.doi.org/10.1108/ec-09-2015-0284.
Full textAbstract:
Purpose The purpose of this paper is to capture the actual structural behavior of the longest timber footbridge in Spain by means of a multi-scale model updating approach in conjunction with ambient vibration tests. Design/methodology/approach In a first stage, a numerical pre-test analysis of the full bridge is performed, using standard beam-type finite elements with isotropic material properties. This approach offers a first structural model in which optimal sensor placement (OSP) methodologies are applied to improve the system identification process. In particular, the effective independence (EFI) method is used to determine the optimal locations of a set of sensors. Ambient vibration tests are conducted to determine experimentally the modal characteristics of the structure. The identified modal parameters are compared with those values obtained from this preliminary model. To improve the accuracy of the numerical predictions, the material response is modeled by means of a homogenization-based multi-scale computational approach. In a second stage, the structure is modeled by means of three-dimensional solid elements with the above material definition, capturing realistically the full orthotropic mechanical properties of wood. A genetic algorithm (GA) technique is adopted to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally. Findings An overall good agreement is found between the results of the updated numerical simulations and the corresponding experimental measurements. The longitudinal and transverse Young's moduli, sliding and rolling shear moduli, density and natural frequencies are computed by the present approach. The obtained results reveal the potential predictive capabilities of the present GA/multi-scale/experimental approach to capture accurately the actual behavior of complex materials and structures. Originality/value The uniqueness and importance of this structure leads to an intensive study of its structural behavior. Ambient vibration tests are carried out under environmental excitation. Extraction of modal parameters is obtained from output-only experimental data. The EFI methodology is applied for the OSP on a large-scale structure. Information coming from several length scales, from sub-micrometer dimensions to macroscopic scales, is included in the material definition. The strong differences found between the stiffness along the longitudinal and transverse directions of wood lumbers are incorporated in the structural model. A multi-scale model updating approach is carried out by means of a GA technique to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally.
10
Tian, Yan, Xun Wang, Jiachen Wu, Ruili Wang, and Bailin Yang. "Multi-scale Hierarchical Residual Network for Dense Captioning." Journal of Artificial Intelligence Research 64 (January 30, 2019): 181–96. http://dx.doi.org/10.1613/jair.1.11338.
Full textAbstract:
Recent research on dense captioning based on the recurrent neural network and the convolutional neural network has made a great progress. However, mapping from an image feature space to a description space is a nonlinear and multimodel task, which makes it difficult for the current methods to get accurate results. In this paper, we put forward a novel approach for dense captioning based on hourglass-structured residual learning. Discriminant feature maps are obtained by incorporating dense connected networks and residual learning in our model. Finally, the performance of the approach on the Visual Genome V1.0 dataset and the region labelled MS-COCO (Microsoft Common Objects in Context) dataset are demonstrated. The experimental results have shown that our approach outperforms most current methods.
Dissertations / Theses on the topic "Multi-scale experimental approach"
1
Bütehorn, Steffen [Verfasser]. "Experimental and Numerical Investigation of the Hydrodynamics of Microfiltration Processes Using a Multi-Scale Approach / Steffen Bütehorn." Aachen : Shaker, 2011. http://d-nb.info/1072592649/34.
Full text
2
Tecle, Amanuel Sebhatu. "Evaluation of Wind-Induced Internal Pressure In Low-Rise Buildings: A Multi Scale Experimental and Numerical Approach." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/529.
Full textAbstract:
Hurricane is one of the most destructive and costly natural hazard to the built environment and its impact on low-rise buildings, particularity, is beyond acceptable. The major objective of this research was to perform a parametric evaluation of internal pressure (IP) for wind-resistant design of low-rise buildings and wind-driven natural ventilation applications. For this purpose, a multi-scale experimental, i.e. full-scale at Wall of Wind (WoW) and small-scale at Boundary Layer Wind Tunnel (BLWT), and a Computational Fluid Dynamics (CFD) approach was adopted. This provided new capability to assess wind pressures realistically on internal volumes ranging from small spaces formed between roof tiles and its deck to attic to room partitions. Effects of sudden breaching, existing dominant openings on building envelopes as well as compartmentalization of building interior on the IP were systematically investigated.
Results of this research indicated: (i) for sudden breaching of dominant openings, the transient overshooting response was lower than the subsequent steady state peak IP and internal volume correction for low-wind-speed testing facilities was necessary. For example a building without volume correction experienced a response four times faster and exhibited 30-40% lower mean and peak IP; (ii) for existing openings, vent openings uniformly distributed along the roof alleviated, whereas one sided openings aggravated the IP; (iii) larger dominant openings exhibited a higher IP on the building envelope, and an off-center opening on the wall exhibited (30-40%) higher IP than center located openings; (iv) compartmentalization amplified the intensity of IP and; (v) significant underneath pressure was measured for field tiles, warranting its consideration during net pressure evaluations. The study aimed at wind driven natural ventilation indicated: (i) the IP due to cross ventilation was 1.5 to 2.5 times higher for Ainlet/Aoutlet>1 compared to cases where Ainlet/AoutletCFD based IP responses. Comparisons with ASCE 7-10 consistently demonstrated that the code underestimated peak positive and suction IP.
3
Syerko, Oléna. "Tensile and bending behavior of dry fibrous materials : experimental study and modeling by multi-scale asymptotic homogenization approach." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10154.
Full textAbstract:
Les renforts fibreux secs utilisés dans les composites structuraux sont composés d'un arrangement de fils eux-même constitués de milliers de fibres. Etant données la complexe architecture multi-échelle et la faible cohésion entre leurs constituants, ils montrent des propriétés en traction de plusieurs ordres de grandeurs supérieurs à ceux en flexion. Dans ce contexte, ce travail porte sur l'étude de la traction et de la flexion de matériaux fibreux en tenant compte de leur réalité géométrique à l'échelle mésoscopique, à la fois expérimentalement et analytiquement. Les matériaux tissés, ayant une ondulation périodique, sont considérés. Une nouvelle méthodologie a été développée pour la modélisation du comportement de structures ondulées (avec une variable rapide) en re-projetant des forces, moments et déplacements sur l'axe neutre de la structure. Les solutions exactes des problèmes sur la traction et flexion d'une poutre sont obtenues. En parallèle, les tissus et fils extraits ont été testés en flexion et traction. Les rigidités des fils ont été extraites en couplant l'analyse d'image et une méthode inverse. En général les résultats expérimentaux ont démontré un lien entre l'ondulation de la structure et les propriétés résultantes. De plus, ils ont montré l'applicabilité de la méthode d'homogénéisation réalisée. Enfin, l'approche permet de poser et résoudre le problème d'optimisation de l'architecture fibreuse au travers de la géométrie des fils constitutifsDry fiber reinforcements used in structural composites consist of arrangements of yarns themselves consisting of alignments of thousands of fibers. Due to the complex multi-scale architecture and low cohesion between their constituents, they exhibit tensile properties several orders of magnitude higher than the bending ones. This work aims at studying the tensile and bending behaviors of fibrous materials, taking into account their meso-scale architecture, both experimentally and analytically. Woven fabrics, owing a periodic and corrugated geometry of their inter-weaved yarns, are under consideration. A new methodology has been developed for the modeling of the stress-strain state of corrugated structures (with fastly variable parameters) re-projecting applied forces, moments, and displacements on the neutral axis of the structure. The exact solutions for the problems about tension and bending of a beam have been obtained. In parallel, fabrics and constituting yarns have been tested on a bending set-up based on the cantilever principle. Tensile tests have also been performed on yarns extracted from the considered fabrics. Tensile and bending properties of yarns have been identified from tests coupling image analysis and inverse method. In general, the experimental results have demonstrated the link between the structure with corrugated constituents and its mechanical response to loadings. Also, they have justified the applicability of the multi-scale homogenization method for the prediction of effective properties. Finally, the approach permits to set and to efficiently solve the problem of the optimal design of fibrous materials from the crimped constituents geometry
4
Francis, Cathy, and n/a. "A multi-scale investigation into the effects of permanent inundation on the flood pulse, in ephemeral floodplain wetlands of the River Murray." University of Canberra. Health, Design & Science, 2005. http://erl.canberra.edu.au./public/adt-AUC20061128.153926.
Full textAbstract:
Using a multi-scale experimental approach, the research undertaken in this thesis investigated the role
of the flood pulse in ephemeral floodplain wetlands of the River Murray, in order to better understand
the impact of river regulation (and permanent inundation) on these wetlands.
An ecosystem-based experiment was conducted on the River Murray floodplain, to compare changes
in nutrient availability and phytoplankton productivity in three ephemeral wetlands (over a drying/reflooding
cycle) with three permanently inundated wetlands. In the ephemeral wetlands, both drying
and re-flooding phases were associated with significant increases in nutrient availability and, in some
cases, phytoplankton productivity. It was demonstrated that the ?flood pulse?, as described by the
Flood Pulse Concept (FPC), can occur in ephemeral wetlands in dryland river-floodplain systems,
although considerable variation in the nature of the pulse existed amongst these wetlands. Results of
this experiment suggest that factors such as the degree of drying and length of isolation during the dry
phase, the rate of re-filling, timing of re-flooding and the number of drying/re-flooding cycles may be
potentially important in producing the variation observed.
Permanent inundation of ephemeral wetlands effectively removed these periods of peak nutrient
availability and phytoplankton productivity, resulting in continuously low levels (of nutrient availability
and phytoplankton productivity). It was concluded that alteration of the natural hydrological cycle in
this way can significantly reduce nutrient availability, primary production and secondary production,
essentially changing the structure and function, the ecology, of these wetlands. Equally, the results of
this experiment indicate that some of the changes resulting from river regulation and permanent
inundation can be somewhat reversed, within a relatively short period of time, given re-instatement of
a more natural hydrological regime.
A mesocosm experiment was used to examine the influence of the dry phase, specifically the effect of
the degree of wetland drying, on patterns of nutrient availability and primary productivity comprising
the flood pulse. Compared to permanent inundation, re-flooding of completely desiccated sediments
increased carbon (C) and nitrogen (N) availability while partial drying generally decreased, or had little
effect on, C and N availability after re-flooding. However, degree of drying had little effect on
phosphorus availability or rates of primary production measured after re-flooding, and it is possible
that these two factors are related. Partial drying reduced rates of community respiration after reflooding,
possibly a reflection of the reduced carbon concentrations measured in these mesocosms in
this phase of the experiment. Degree of drying also influenced the macrophyte community (measured
after three months of flooding), with plant biomass generally decreasing and species diversity
increasing as the degree of drying increased (with the exception of complete sediment desiccation
which had lasting negative effects on both macrophyte biomass and species diversity).
The results of the ecosystem and mesocosm experiments were utilised, in addition to results collected
from the same experiment conducted at two smaller scales (minicosms and microcosms), to assess
whether the effects of hydrological regime on nutrient availability at the ?wetland? scale could be
replicated in smaller-scale experiments. None of the smaller-scaled experiments included in this
investigation were able to replicate the specific response to hydrological regime recorded at the
ecosystem scale, however the mesocosm experiment did produce results that were more similar to
those at the ecosystem scale than those produced by the mini and microcosm experiments. The
results of this study indicated that extrapolation of results from small-scale experiments should be
undertaken with caution, and confirmed that a multi-scale approach to ecological research is wise,
where large-scale field experimentation and/or monitoring provides a check on the accuracy, and
hence relevance, of conclusions reached via mesocosm experiments.
5
De, Souza Lima Roger Williams. "Drying droplets as a template for multi-component solid particles : experimental study and modeling at the droplet scale Drying droplet as a template for solid formation: a review In situ Raman composition profiling in drying droplets." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2020. http://www.theses.fr/2020EMAC0003.
Full textAbstract:
Les gouttes liquides se sont avérées l’un des principaux vecteurs pour la génération de particules solides à propriétés contrôlées. Ce type de vecteur est utilisé dans plusieurs domaines industriels, y compris le séchage par atomisation. Le développement de ces particules structurées est poussé par la demande pour des particules à propriétés contrôlées, comme la cinétique de dissolution, le relargage contrôlé ou la réactivité. Le principal verrou scientifique est la description détaillée de la distribution des constituants au sein de la goutte pendant le séchage, en plus de la prédiction de la morphologie de la particule finale. L'objectif de cette thèse est de comprendre, par une approche couplée modélisation/expérimentation, comment les conditions de séchage et les formulations liquides impactent la structure de la poudre. L'étude expérimentale a d'abord été réalisée dans un sécheur par atomisation à l'échelle laboratoire pour la création d'une cartographie représentant les morphologies obtenues pour les deux systèmes de séchage. Un dispositif expérimental a été conçu de manière à étudier la formation d'une particule solide à partir d'une goutte suspendue par un filament, ce qui permet d'appréhender des éléments fondamentaux relatifs au séchage de la goutte ainsi que des aspects sur la modification de la structure solide. Une nouveauté explorée à l'échelle de la goutte avec un lévitateur acoustique consistait à appliquer la spectroscopie Raman in situ afin d'évaluer l'évolution de la distribution spatiale de deux composants lors du séchage de la goutte. Enfin, un modèle de séchage de goutte en 2-D avec la Dynamique des Fluides Numérique est conçu, ce qui permet de quantifier la distribution spatiale des composants de la goutte sous un séchage convectif, jusqu’à la formation de la croûte. Une analyse de sensibilité est réalisée de manière à montrer l'influence des conditions expérimentales sur la cinétique de séchage et la distribution spatiale des solutésLiquid droplets are one of the major means of generation of solid particles with controlled. These templates are encountered with a variety of industrial processes, among them, spray drying. These tailored structures would meet the demand for particles with controlled properties, like improved kinetics, sustained release or controlled reactivity. The major scientific obstacle is the detailed description of the components distribution inside the droplet during drying, besides prediction of the final particle morphology. An experimental/modeling approach is undertaken in this thesis to understand how the drying conditions and the liquid formulation impact the final structure of the powders. The drying systems studied were sucrose-dextran and lactose-whey protein isolate aqueous solutions. The experimental work was firstly carried out at the lab-scale spray-dryer giving a reference picture of the possible particle morphologies for the drying systems. An experimental set-up was designed and developed to suspend a liquid droplet by a filament, from which the droplet mass variation over time could be accurately measured, giving fundamental insight into the drying process and allowing the analysis of the modification of the solid structures. A novelty explored at the droplet scale with an acoustic levitator was to apply an in situ Raman spectroscopy to assess the evolution of the spatial distribution of two components in drying droplets. Finally, a 2-D droplet drying model using Computational Fluid Dynamics was developed for allowing the assessment of the spatial distribution of the droplet components under a convective drying, until the formation of a crust. A sensitivity analysis was performed in order to show the influence of the experimental conditions on the drying kinetics and the component spatial distribution
6
Mallangi, Siva Sai Reddy. "Low-Power Policies Based on DVFS for the MUSEIC v2 System-on-Chip." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229443.
Full textAbstract:
Multi functional health monitoring wearable devices are quite prominent these days. Usually these devices are battery-operated and consequently are limited by their battery life (from few hours to a few weeks depending on the application). Of late, it was realized that these devices, which are currently being operated at fixed voltage and frequency, are capable of operating at multiple voltages and frequencies. By switching these voltages and frequencies to lower values based upon power requirements, these devices can achieve tremendous benefits in the form of energy savings. Dynamic Voltage and Frequency Scaling (DVFS) techniques have proven to be handy in this situation for an efficient trade-off between energy and timely behavior. Within imec, wearable devices make use of the indigenously developed MUSEIC v2 (Multi Sensor Integrated circuit version 2.0). This system is optimized for efficient and accurate collection, processing, and transfer of data from multiple (health) sensors. MUSEIC v2 has limited means in controlling the voltage and frequency dynamically. In this thesis we explore how traditional DVFS techniques can be applied to the MUSEIC v2. Experiments were conducted to find out the optimum power modes to efficiently operate and also to scale up-down the supply voltage and frequency. Considering the overhead caused when switching voltage and frequency, transition analysis was also done. Real-time and non real-time benchmarks were implemented based on these techniques and their performance results were obtained and analyzed. In this process, several state of the art scheduling algorithms and scaling techniques were reviewed in identifying a suitable technique. Using our proposed scaling technique implementation, we have achieved 86.95% power reduction in average, in contrast to the conventional way of the MUSEIC v2 chip’s processor operating at a fixed voltage and frequency. Techniques that include light sleep and deep sleep mode were also studied and implemented, which tested the system’s capability in accommodating Dynamic Power Management (DPM) techniques that can achieve greater benefits. A novel approach for implementing the deep sleep mechanism was also proposed and found that it can obtain up to 71.54% power savings, when compared to a traditional way of executing deep sleep mode.Nuförtiden så har multifunktionella bärbara hälsoenheter fått en betydande roll. Dessa enheter drivs vanligtvis av batterier och är därför begränsade av batteritiden (från ett par timmar till ett par veckor beroende på tillämpningen). På senaste tiden har det framkommit att dessa enheter som används vid en fast spänning och frekvens kan användas vid flera spänningar och frekvenser. Genom att byta till lägre spänning och frekvens på grund av effektbehov så kan enheterna få enorma fördelar när det kommer till energibesparing. Dynamisk skalning av spänning och frekvens-tekniker (såkallad Dynamic Voltage and Frequency Scaling, DVFS) har visat sig vara användbara i detta sammanhang för en effektiv avvägning mellan energi och beteende. Hos Imec så använder sig bärbara enheter av den internt utvecklade MUSEIC v2 (Multi Sensor Integrated circuit version 2.0). Systemet är optimerat för effektiv och korrekt insamling, bearbetning och överföring av data från flera (hälso) sensorer. MUSEIC v2 har begränsad möjlighet att styra spänningen och frekvensen dynamiskt. I detta examensarbete undersöker vi hur traditionella DVFS-tekniker kan appliceras på MUSEIC v2. Experiment utfördes för att ta reda på de optimala effektlägena och för att effektivt kunna styra och även skala upp matningsspänningen och frekvensen. Eftersom att ”overhead” skapades vid växling av spänning och frekvens gjordes också en övergångsanalys. Realtidsoch icke-realtidskalkyler genomfördes baserat på dessa tekniker och resultaten sammanställdes och analyserades. I denna process granskades flera toppmoderna schemaläggningsalgoritmer och skalningstekniker för att hitta en lämplig teknik. Genom att använda vår föreslagna skalningsteknikimplementering har vi uppnått 86,95% effektreduktion i jämförelse med det konventionella sättet att MUSEIC v2-chipets processor arbetar med en fast spänning och frekvens. Tekniker som inkluderar lätt sömn och djupt sömnläge studerades och implementerades, vilket testade systemets förmåga att tillgodose DPM-tekniker (Dynamic Power Management) som kan uppnå ännu större fördelar. En ny metod för att genomföra den djupa sömnmekanismen föreslogs också och enligt erhållna resultat så kan den ge upp till 71,54% lägre energiförbrukning jämfört med det traditionella sättet att implementera djupt sömnläge.
Book chapters on the topic "Multi-scale experimental approach"
1
Jiang, Ping, and Tao Gao. "A Novel Detection Method of Paper Defects Based on Visual Attention Mechanism." In Global Applications of Pervasive and Ubiquitous Computing, 159–65. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2645-4.ch018.
Full textAbstract:
In this paper, an improved paper defects detection method based on visual attention mechanism computation model is presented. First, multi-scale feature maps are extracted by linear filtering. Second, the comparative maps are obtained by carrying out center-surround difference operator. Third, the saliency map is obtained by combining conspicuity maps, which is gained by combining the multi-scale comparative maps. Last, the seed point of watershed segmentation is determined by competition among salient points in the saliency map and the defect regions are segmented from the background. Experimental results show the efficiency of the approach for paper defects detection.
2
Kushnure, Devidas Tulshiram, and Sanjay Nilkanth Talbar. "M2UNet++." In Advances in Healthcare Information Systems and Administration, 256–73. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-7709-7.ch015.
Full textAbstract:
Liver segmentation is instrumental for decision making in the medical realm for the diagnosis and treatment planning of hepatic diseases. However, the manual segmentation of the hundreds of CT images is tedious for medical experts. Thus, it hampers the segmentation accuracy and is reliant on opinion of the operator. This chapter presents the deep learning-based modified multi-scale UNet++ (M2UNet++) approach for automatic liver segmentation. The multi-scale features were modified channel-wise using adaptive feature recalibration to improve the representation of the high-level semantic information of the skip pathways and improved the segmentation performance with fewer computational overheads. The experimental results proved the model's efficacy on the publicly available 3DIRCADb dataset, which offers significant complexity and variations. The model's dice coefficient value is 97.28% that is 7.64%, and 2.24% improved from the UNet and UNet++ model. The quantitative result analysis shows that the M2UNet++ model outperforms the state-of-the-art methods proposed for liver segmentation.
3
Ghaderi, Abdolsalam. "Investigating of Hybrid Meta-Heuristics to Solve the Large-Scale Multi-Source Weber Problems and Performance Measuring of them with Statistical Tests." In Meta-Heuristics Optimization Algorithms in Engineering, Business, Economics, and Finance, 171–97. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2086-5.ch006.
Full textAbstract:
The location–allocation problems are a class of complicated optimization problems that requires finding sites for m facilities and to simultaneously allocate n customers to those facilities to minimize the total transportation costs. Indeed, these problems, belonging to the class NP-hard, have a lot of local optima solutions. In this chapter, three hybrid meta-heuristics: genetic algorithm, variable neighborhood search and particle swarm optimization, and a hybrid local search approach. These are investigated to solve the uncapacitated continuous location-allocation problem (multi-source Weber problem). In this regard, alternate location allocation and exchange heuristics are used to find the local optima of the problem within the framework of hybrid algorithms. In addition, some large-scale problems are employed to measure the effectiveness and efficiency of hybrid algorithms. Obtained results from these heuristics are compared with local search methods and with each other. The experimental results show that the hybrid meta-heuristics produce much better solutions to solve large-scale problems. Moreover, the results of two non-parametric statistical tests detected a significant difference in hybrid algorithms such that the hybrid variable neighborhood search and particle swarm optimization algorithm outperform the others.
4
Hayashi, Hidehiko, and Akinori Minazuki. "Study on Image Quality Assessment with Scale Space Approach Using Index of Visual Evoked Potentials." In E-Activity and Intelligent Web Construction, 165–76. IGI Global, 2011. http://dx.doi.org/10.4018/978-1-61520-871-5.ch014.
Full textAbstract:
This chapter presents an objective assessment method of image quality using visual evoked potentials (VEPs) to image engineer field based on multi-disciplinarily approach such as knowledge of neurobiology, image recognition theory, or computer vision. The multi-disciplinarily based objective assessment method applies Gaussian scale-space filtering in order to define a scalar parameter to depict blur image. In the experiment, visual stimuli are provided by the scalar parameter, and subjects are detected using VEPs. Their VEPs are recoded during observation of the checkerboard pattern reversal (PR) stimuli, and are analyzed with a latency of about Negative 145 msec (N145) component. The result of the experiment was that latency of N145 components were long about10-20 msec when parameters were large vale (more blur). This result shows one example of availableness for the multi-disciplinarily based objective assessment of image quality by integrating the pattern reversal visual evoked potential (PR-VEP) and the scale-space theory.
5
Tlili, Brahim, H. Guizani, K. Aouadi, and M. Nasser. "Multi-Scale Modeling of Mechanobiological Behavior of Bone." In BioMechanics and Functional Tissue Engineering [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95035.
Full textAbstract:
The simulation and theoretical or numerical predictive modeling of the development and growth of biological tissues mainly in the case of bone is a complicated task. As a result, many and various knowledge tools required (experimental, theoretical and numerical) are not yet mastered and even discovered. We will cite here some techniques and methods as well as results specific to the multi-scale numerical modeling methodology, and multiphysics using finite element coupling with neural network computation of biological tissues applied to the predictive behavior of cortical bone based of the microstructure of their local constituents and their reconstruction according to local mechanobiology. It follows that additional work is necessary to give more precision on the different models, the considered approaches show their potential utility to understand this behavior in terms of biological evolutions as well as the subsequent use in medical applications.
6
Chen, Zhengzheng, and Chao Wu. "Ab Initio-Based Stochastic Simulations of Kinetic Processes on Surfaces." In Advances in Chemical and Materials Engineering, 28–60. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-5225-0290-6.ch003.
Full textAbstract:
We briefly present the theoretical framework of a hierarchical multi-scale approach, which is an ab initio-based stochastic method, and its applications to several chemical/physical kinetic processes on metallic surfaces. We first introduce necessary theoretical basis of ab initio and Monte Carlo (MC) methods, and then illustrate different Monte Carlo algorithms for important ensembles, including canonical and grand canonical ensembles. In the following section, we describe two important protocols which are essential to integrate ab initio data and MC models. Two examples are presented in order to elucidate the power of this multi-scale approach. The first example focuses on the combination of kinetic Monte Carlo and transition state theory. We discuss the detailed processes of performing kinetic Monte Carlo simulation on atomic diffusion on alloyed surface, including some technical aspects. In the second example, we presents a different way to account for the local environment-sensitive metal-catalyzed O2 dissociation reactions using combinatory techniques including cluster expansion and grand canonical Monte Carlo methods. This approach provides steady-state rates and rate derivatives that are comparable with experiments. Moreover, the connection between the feasible mechanisms and the observed kinetic behaviors can now be built.
7
Chen, Yini, Zuhua Jiang, and Baihe Li. "A Hybrid Heuristic Optimization Approach for Green Flatcar Transportation Scheduling in Shipbuilding." In Advances in Transdisciplinary Engineering. IOS Press, 2020. http://dx.doi.org/10.3233/atde200089.
Full textAbstract:
To increase efficiency and decrease energy in fierce competition, higher standard of transportation scheduling mode for shipbuilding is necessary and urgent. By analyzing the “one-vehicle and one-cargo” transportation scheduling problem in shipbuilding, this paper proposes a bi-objective mathematical model and design a Multi-Objective Tabu Search algorithm(MOTS) to minimize total carbon emission and transportation time cost. Further, to improve the computation performance of the solution method, we combined NSGA-âĚą and MOTS to design a hybrid heuristic algorithm. Computational experiments compare three optimizing approaches and reveal that MOTS and NSGAâĚą-MOTS have certain advantages in terms of solution effect and convergence speed in large-scale instances. The case shows the proposed optimization approach can reduce carbon emissions by 61.22% for daily transportation.
8
Samal, M. K. "Numerical Simulation of High Temperature Deformation Behavior of Nickel-Based Superalloys Using Crystal Plasticity Models and Finite Element Method." In Mathematical Concepts and Applications in Mechanical Engineering and Mechatronics, 414–46. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1639-2.ch020.
Full textAbstract:
Development of reliable computational models to predict the high temperature deformation behavior of nickel based super-alloys is in the forefront of materials research. These alloys find wide applications in manufacturing of turbine blades and discs of aircraft engines. The micro-structure of these alloys consists of the primary gamma-prime phase and the secondary and tertiary precipitates (of Ni3Al type) are dispersed as gamma-prime phases in the gamma-matrix. It is computationally expensive to incorporate the explicit finite element model of the micro-structure in a crystal plasticity based constitutive framework to simulate the response of the polycrystalline micro-structure. Existing models in literature do not account for these underlying micro-structural features which are important for simulation of polycrystalline response. The aim of this chapter is to present a physically-motivated multi-scale approach for simulation of high temperature response of Nickel-based super-alloys. At the lower length scale, a dislocation density based crystal plasticity model is developed which simulates the response of various types of micro-structures. The micro-structures are designed with various shapes and volume fractions of gamma-prime precipitates. A new model for simulation of the mechanism of anti-phase boundary shearing of the gamma-prime precipitates, by the matrix dislocations, is presented in this chapter. The lower scale model is homogenized as a function of various micro-structural parameters and the homogenized model is used in the next scale of multi-scale simulation. In addition, a new criterion for initiation of micro-twin and a constitutive model for twin strain accumulation are developed. This new micro-twin model along with the homogenized crystal plasticity model has been used to simulate the creep response of a single crystal nickel-based super-alloy and the results have been compared with those of experiment from literature. It was observed that the new model has been able to model the tension-compression asymmetry as observed in single crystal experiments.
9
Samal, M. K. "Numerical Simulation of High Temperature Deformation Behavior of Nickel-Based Superalloys Using Crystal Plasticity Models and Finite Element Method." In Materials Science and Engineering, 341–73. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1798-6.ch013.
Full textAbstract:
Development of reliable computational models to predict the high temperature deformation behavior of nickel based super-alloys is in the forefront of materials research. These alloys find wide applications in manufacturing of turbine blades and discs of aircraft engines. The micro-structure of these alloys consists of the primary gamma-prime phase and the secondary and tertiary precipitates (of Ni3Al type) are dispersed as gamma-prime phases in the gamma-matrix. It is computationally expensive to incorporate the explicit finite element model of the micro-structure in a crystal plasticity based constitutive framework to simulate the response of the polycrystalline micro-structure. Existing models in literature do not account for these underlying micro-structural features which are important for simulation of polycrystalline response. The aim of this chapter is to present a physically-motivated multi-scale approach for simulation of high temperature response of Nickel-based super-alloys. At the lower length scale, a dislocation density based crystal plasticity model is developed which simulates the response of various types of micro-structures. The micro-structures are designed with various shapes and volume fractions of gamma-prime precipitates. A new model for simulation of the mechanism of anti-phase boundary shearing of the gamma-prime precipitates, by the matrix dislocations, is presented in this chapter. The lower scale model is homogenized as a function of various micro-structural parameters and the homogenized model is used in the next scale of multi-scale simulation. In addition, a new criterion for initiation of micro-twin and a constitutive model for twin strain accumulation are developed. This new micro-twin model along with the homogenized crystal plasticity model has been used to simulate the creep response of a single crystal nickel-based super-alloy and the results have been compared with those of experiment from literature. It was observed that the new model has been able to model the tension-compression asymmetry as observed in single crystal experiments.
10
Steiner, T., Y. Jin, L. Schramm, and B. Sendhoff. "Dynamic Links and Evolutionary History in Simulated Gene Regulatory Networks." In Handbook of Research on Computational Methodologies in Gene Regulatory Networks, 498–522. IGI Global, 2010. http://dx.doi.org/10.4018/978-1-60566-685-3.ch021.
Full textAbstract:
In this chapter, we describe the use of evolutionary methods for the in silico generation of artificial gene regulatory networks (GRNs). These usually serve as models for biological networks and can be used for enhancing analysis methods in biology. We clarify our motivation in adopting this strategy by showing the importance of detailed knowledge of all processes, especially the regulatory dynamics of interactions undertaken during gene expression. To illustrate how such a methodology works, two different approaches to the evolution of small-scale GRNs with specified functions, are briefly reviewed and discussed. Thereafter, we present an approach to evolve medium sized GRNs with the ability to produce stable multi-cellular growth. The computational method employed allows for a detailed analysis of the dynamics of the GRNs as well as their evolution. We have observed the emergence of negative feedback during the evolutionary process, and we suggest its implication to the mutational robustness of the regulatory network which is further supported by evidence observed in additional experiments.
Conference papers on the topic "Multi-scale experimental approach"
1
Viswanathan, Hari, J. William Carey, Luke Frash, Satish Karra, Jeffrey Hyman, Qinjun Kang, Esteban Rougier, and Gowri Srinivasan. "A MULTI-SCALE EXPERIMENTAL AND SIMULATION APPROACH FOR IMPROVING HYDRAULIC FRACTURING." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-300988.
Full text
2
Maxwell, James L., and Joseph Pegna. "Experimental Developments Toward Multi-Material Micron Scale Rapid Prototyping." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0030.
Full textAbstract:
Abstract Rapid prototyping of millimeter- to micron-scale mechanical parts was obtained by selective Laser Induced Chemical Vapor Deposition (LCVD) onto a computer controlled five degree of freedom substrate. A description of Rensselaer’s experimental apparatus for 3-dimensional rapid prototyping is given. Details of the (LCVD) system are presented as well as the experimental approach taken. We illustrate our purpose with sample carbon micro-structures obtained during system calibration. By virtue of the process selected, the range of material that can be deposited is as large as there are organometallic precursors for them. Many ceramics, intermetallics, metals, and possibly some polymers can be grown via this method.
3
K. Tsou, Benjamin, Derek F. Wong, and Ka Po Chow. "Towards the Generation of Bilingual Chinese-English Multi-word Expressions from Large Scale Parallel Corpora: An Experimental Approach." In EUROPHRAS 2017 - Computational and Corpus-based Phraseology: Recent Advances and Interdisciplinary Approaches. Editions Tradulex, Geneva, Switzerland, 2017. http://dx.doi.org/10.26615/978-2-9701095-2-5_022.
Full text
4
Mer, Samuel, Olivier Praud, Jacques Magnaudet, and Véronique Roig. "Simulating the Emptying of a Water Bottle With a Multi-Scale Two-Fluid Approach." In ASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/fedsm2018-83196.
Full textAbstract:
Multiple industrial processes involve gas-liquid flows characterized by a wide range of spatial and temporal scales. Simulating such flows remains a major challenge nowadays, as the computational cost associated with Direct Numerical Simulation still makes it unaffordable. For such configurations, an interesting alternative to DNS is the use of multi-scale approaches. In the latter, large enough bubbles are fully resolved and may deform over time, while smaller bubbles are modeled as a dispersed phase using subgrid scale models. The interfacial momentum transfer terms are then tailored to the local flow configuration. The closure models still involved in these approaches and the influence of the cut-off length separating the resolved and modeled bubbles definitely need to be validated against detailed experiments. In order to assess the validity of these models, we present a one-to-one comparison between experiments performed in a simple configuration, namely the emptying of a water bottle, and numerical simulations using the aforementioned approach. The results are found to reliably reproduce the genesis of the oscillation mechanism, which is governed by the bubble formation at the bottle neck. The multi-scale model also qualitatively reproduces the fragmentation process of large bubbles during their rise in the water column. However local experimental data are required to assess more quantitatively these results.
5
Dumouchel, Christophe. "Liquid Atomization and Spray: A Multi-Scale Description." In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69590.
Full textAbstract:
A multi-scale approach to investigate liquid atomization processes is introduced. It describes the liquid system by the scale distribution whose determination is inspired from the Euclidean Distance Mapping used to measure the fractal dimension of a contour. The scale distribution is introduced in 2D and in 3D and applications from previous investigations are presented. The 2D applications are performed on experimental images and the 3D applications are performed on results obtained from Direct Numerical Simulation. The multi-scale analysis allows identifying and quantifying the mechanisms responsible for the interface evolution according to the scale. Among other results, the analyses presented here demonstrate the improvement of the atomization process when an elongation mechanism contributes to the thinning of the small structures. The multi-scale tool also provides new metrics that may be used to validate simulation results. An example of this is presented and discussed. Finally, the paper evokes several approaches to implementing the scale-distribution concept to improve or build new models.
6
Zhao, Shanshan, Xi Li, and Omar El Farouk Bourahla. "Deep Optical Flow Estimation Via Multi-Scale Correspondence Structure Learning." In Twenty-Sixth International Joint Conference on Artificial Intelligence. California: International Joint Conferences on Artificial Intelligence Organization, 2017. http://dx.doi.org/10.24963/ijcai.2017/488.
Full textAbstract:
As an important and challenging problem in computer vision, learning based optical flow estimation aims to discover the intrinsic correspondence structure between two adjacent video frames through statistical learning. Therefore, a key issue to solve in this area is how to effectively model the multi-scale correspondence structure properties in an adaptive end-to-end learning fashion. Motivated by this observation, we propose an end-to-end multi-scale correspondence structure learning (MSCSL) approach for optical flow estimation. In principle, the proposed MSCSL approach is capable of effectively capturing the multi-scale inter-image-correlation correspondence structures within a multi-level feature space from deep learning. Moreover, the proposed MSCSL approach builds a spatial Conv-GRU neural network model to adaptively model the intrinsic dependency relationships among these multi-scale correspondence structures. Finally, the above procedures for correspondence structure learning and multi-scale dependency modeling are implemented in a unified end-to-end deep learning framework. Experimental results on several benchmark datasets demonstrate the effectiveness of the proposed approach.
7
Peng, Cheng-Lun, An Tao, and Xin Geng. "Label Embedding Based on Multi-Scale Locality Preservation." In Twenty-Seventh International Joint Conference on Artificial Intelligence {IJCAI-18}. California: International Joint Conferences on Artificial Intelligence Organization, 2018. http://dx.doi.org/10.24963/ijcai.2018/364.
Full textAbstract:
Label Distribution Learning (LDL) fits the situations well that focus on the overall distribution of the whole series of labels. The numerical labels of LDL satisfy the integrity probability constraint. Due to LDL's special label domain, existing label embedding algorithms that focus on embedding of binary labels are thus unfit for LDL. This paper proposes a specially designed approach MSLP that achieves label embedding for LDL by Multi-Scale Locality Preserving (MSLP). Specifically, MSLP takes the locality information of data in both the label space and the feature space into account with different locality granularity. By assuming an explicit mapping from the features to the embedded labels, MSLP does not need an additional learning process after completing embedding. Besides, MSLP is insensitive to the existing of data points violating the smoothness assumption, which is usually caused by noises. Experimental results demonstrate the effectiveness of MSLP in preserving the locality structure of label distributions in the embedding space and show its superiority over the state-of-the-art baseline methods.
8
Weisgraber, Todd H., Stuart D. C. Walsh, Kostas Karazis, and Dennis Gottuso. "Multi-Scale Fluid-Structure Interaction Simulations Based on Mesoscopic Approaches." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-38799.
Full textAbstract:
Many challenging fluid-structure interaction problems in nuclear engineering remain unresolved because current CFD methodologies are unable to manage the number of computational cells needed and/or the difficulties associated with meshing changing geometries. One of the most promising recent methodologies for fluid dynamics modeling is the lattice-Boltzmann method — an approach that offers significant advantages over classical CFD methodologies by 1) greatly reducing meshing requirements, 2) offering great scalability, and 3) through relative ease of code parallelization. While LBM often requires increased numerical effort compared to other methods, this can be dramatically reduced by combining LBM with Adaptive Mesh Refinement (LB-AMR). This study describes an ongoing collaboration investigating nuclear fuel-assembly spacer grid performance. The LB-AMR method, used to simulate the flow field around a specific spacer grid design, is capable of describing turbulent flows for high Reynolds numbers, revealing rich flow dynamics in good qualitative agreement with experimental results. Prepared by LLNL under Contract DE-AC52-07NA27344.
9
Ding, Qianggang, Sifan Wu, Hao Sun, Jiadong Guo, and Jian Guo. "Hierarchical Multi-Scale Gaussian Transformer for Stock Movement Prediction." In Twenty-Ninth International Joint Conference on Artificial Intelligence and Seventeenth Pacific Rim International Conference on Artificial Intelligence {IJCAI-PRICAI-20}. California: International Joint Conferences on Artificial Intelligence Organization, 2020. http://dx.doi.org/10.24963/ijcai.2020/640.
Full textAbstract:
Predicting the price movement of finance securities like stocks is an important but challenging task, due to the uncertainty of financial markets. In this paper, we propose a novel approach based on the Transformer to tackle the stock movement prediction task. Furthermore, we present several enhancements for the proposed basic Transformer. Firstly, we propose a Multi-Scale Gaussian Prior to enhance the locality of Transformer. Secondly, we develop an Orthogonal Regularization to avoid learning redundant heads in the multi-head self-attention mechanism. Thirdly, we design a Trading Gap Splitter for Transformer to learn hierarchical features of high-frequency finance data. Compared with other popular recurrent neural networks such as LSTM, the proposed method has the advantage to mine extremely long-term dependencies from financial time series. Experimental results show our proposed models outperform several competitive methods in stock price prediction tasks for the NASDAQ exchange market and the China A-shares market.
10
Metzger, Lukas, and Matthias Kind. "Compartment Method for Dynamic Multi-Scale Simulation of Precipitation Reactors." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21547.
Full textAbstract:
Precipitation crystallization is one possibility to produce nano-scaled solid particles from the liquid phase. High nucleation and growth rates are generated by mixing two well soluble reactants and their subsequent reaction to a sparingly soluble product. These primary processes can be very fast. Therefore experimental access to internal parameters is given insufficiently due to predominantly very short process times. Computational Fluid Dynamics (CFD) based methods are a promising tool to gain insight into those inaccessible processes. Unfortunately, 3D modeling of complex precipitation reactors poses enormous difficulties and computational costs to CFD especially in the production scale under the aspect of macroscopic flowfields down to microscale modeling of mixing, rheology and particle formation. Therefore, a new methodic approach is presented that is able to handle these complex interactions. Due to local and temporal multiscale complexity, it is not advisable to model the complete apparatus. One basic principle of the methodical consideration is the arrangement of cross-linked compartments to reduce the huge unsimulatable control volume in its complexity and dimensions. Thereby, population balance equations (PBE) are solved, using CFD measured, average state variables, with a discrete one-dimensional High Resolution Finite Volume (HRFV) algorithm. Nevertheless appropriate fundamental kinetics for primary and secondary processes have to be implemented. Besides the new methodic approach, this paper deals with the influence of temporal supersaturation buildup on the product particle distribution. It is shown that important conclusions about the mixing behavior of Confined Impinging Jet mixers (CIJMs) can be drawn by coupling CFD and external population balancing even without any micromixing model. The contribution provides an insight into the methodic approach and first derived results.
Reports on the topic "Multi-scale experimental approach"
1
Chapman, Ray, Phu Luong, Sung-Chan Kim, and Earl Hayter. Development of three-dimensional wetting and drying algorithm for the Geophysical Scale Transport Multi-Block Hydrodynamic Sediment and Water Quality Transport Modeling System (GSMB). Engineer Research and Development Center (U.S.), July 2021. http://dx.doi.org/10.21079/11681/41085.
Full textAbstract:
The Environmental Laboratory (EL) and the Coastal and Hydraulics Laboratory (CHL) have jointly completed a number of large-scale hydrodynamic, sediment and water quality transport studies. EL and CHL have successfully executed these studies utilizing the Geophysical Scale Transport Modeling System (GSMB). The model framework of GSMB is composed of multiple process models as shown in Figure 1. Figure 1 shows that the United States Army Corps of Engineers (USACE) accepted wave, hydrodynamic, sediment and water quality transport models are directly and indirectly linked within the GSMB framework. The components of GSMB are the two-dimensional (2D) deep-water wave action model (WAM) (Komen et al. 1994, Jensen et al. 2012), data from meteorological model (MET) (e.g., Saha et al. 2010 - http://journals.ametsoc.org/doi/pdf/10.1175/2010BAMS3001.1), shallow water wave models (STWAVE) (Smith et al. 1999), Coastal Modeling System wave (CMS-WAVE) (Lin et al. 2008), the large-scale, unstructured two-dimensional Advanced Circulation (2D ADCIRC) hydrodynamic model (http://www.adcirc.org), and the regional scale models, Curvilinear Hydrodynamics in three dimensions-Multi-Block (CH3D-MB) (Luong and Chapman 2009), which is the multi-block (MB) version of Curvilinear Hydrodynamics in three-dimensions-Waterways Experiments Station (CH3D-WES) (Chapman et al. 1996, Chapman et al. 2009), MB CH3D-SEDZLJ sediment transport model (Hayter et al. 2012), and CE-QUAL Management - ICM water quality model (Bunch et al. 2003, Cerco and Cole 1994). Task 1 of the DOER project, “Modeling Transport in Wetting/Drying and Vegetated Regions,” is to implement and test three-dimensional (3D) wetting and drying (W/D) within GSMB. This technical note describes the methods and results of Task 1. The original W/D routines were restricted to a single vertical layer or depth-averaged simulations. In order to retain the required 3D or multi-layer capability of MB-CH3D, a multi-block version with variable block layers was developed (Chapman and Luong 2009). This approach requires a combination of grid decomposition, MB, and Message Passing Interface (MPI) communication (Snir et al. 1998). The MB single layer W/D has demonstrated itself as an effective tool in hyper-tide environments, such as Cook Inlet, Alaska (Hayter et al. 2012). The code modifications, implementation, and testing of a fully 3D W/D are described in the following sections of this technical note.