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Littérature scientifique sur le sujet « Collapse model »

Auteur : Grafiati
Publié le 1 avril 2023

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Articles de revues sur le sujet "Collapse model"

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Mohamadi, Bahaa, Timo Balz et Ali Younes. « Towards a PS-InSAR Based Prediction Model for Building Collapse : Spatiotemporal Patterns of Vertical Surface Motion in Collapsed Building Areas—Case Study of Alexandria, Egypt ». Remote Sensing 12, no 20 (12 octobre 2020) : 3307. http://dx.doi.org/10.3390/rs12203307.

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Buildings are vulnerable to collapse incidents. We adopt a workflow to detect unusual vertical surface motions before building collapses based on PS-InSAR time series analysis and spatiotemporal data mining techniques. Sentinel-1 ascending and descending data are integrated to decompose vertical deformation in the city of Alexandria, Egypt. Collapsed building data were collected from official sources, and overlayed on PS-InSAR vertical deformation results. Time series deformation residuals are used to create a space–time cube in the ArcGIS software environment and analyzed by emerging hot spot analysis to extract spatiotemporal patterns for vertical deformation around collapsed buildings. Our results show two spatiotemporal patterns of new cold spot or new hot spot before the incidents in 66 out of 68 collapsed buildings between May 2015 and December 2018. The method was validated in detail on four collapsed buildings between January and May 2019, proving the applicability of this workflow to create a temporal vulnerability map for building collapse monitoring. This study is a step forward to create a PS-InSAR based model for building collapse prediction in the city.
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Tan, Fei, Wufeiyu Tan, Feifei Yan, Xin Qi, Qinghua Li et Zhikai Hong. « Model Test Analysis of Subsurface Cavity and Ground Collapse Due to Broken Pipe Leakage ». Applied Sciences 12, no 24 (19 décembre 2022) : 13017. http://dx.doi.org/10.3390/app122413017.

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Urban ground collapse is a common geological disaster characterized by its invisible nature, particularly in China, and results in significant socioeconomic losses and even loss of life. Underground pipeline breakage is the most common factor leading to urban ground collapses. Hence, it is essential to study how different types of pipeline breakages initiate the collapse mechanism. In this study, an indoor model test was conducted to directly observe the process of collapse due to broken pipe leakage. A broken pipe was put into a model box and tested by an experimental device. The results showed that among the different pipeline breakage types, vertical damage had the greatest influence on the degree of cavity development and ground collapse. Similarities were observed in the patterns of cavity evolution development and the extent of ground collapse as well, further revealing the significance of the cavity evolution process in predicting ground collapses.
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Kella, Offer, et Andreas Löpker. « A MARKOV-MODULATED GROWTH COLLAPSE MODEL ». Probability in the Engineering and Informational Sciences 24, no 1 (21 décembre 2009) : 99–107. http://dx.doi.org/10.1017/s0269964809990155.

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We consider a growth collapse model in a random environment for which the input rates might depend on the state of an underlying irreducible Markov chain and at state change epochs there is a possible downward jump to a level that is a random fraction of the level just before the jump. The distributions of these jumps are allowed to depend on both the originating and target states. Under a very weak assumption we develop an explicit formula for the conditional moments (of all orders) of the time stationary distribution. We then consider special cases and show how to use this result to study a growth collapse process in which the times between collapses have a phase-type distribution.
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Thorson, James T., Trevor A. Branch et Olaf P. Jensen. « Using model-based inference to evaluate global fisheries status from landings, location, and life history data ». Canadian Journal of Fisheries and Aquatic Sciences 69, no 4 (avril 2012) : 645–55. http://dx.doi.org/10.1139/f2012-016.

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Assessing fishery collapses worldwide is hindered by the lack of biomass data for most stocks, leading to the use of landings-based proxies or the assumption that existing stock assessments are globally representative. We argue that the use of sparse assessments to evaluate fishery status requires model-based inference because assessment availability varies spatially and temporally, and we derive a model that extrapolates from assessment results to available landings, life history, and location data. This model uses logistic regression to classify stocks into different prediction bins and estimates the probability of collapse in each using cross-validation. Results show that landings, life history, and location are informative to discriminate among different probabilities of collapse. We find little evidence that regions with fewer assessments have a greater proportion of collapsed stocks, while acknowledging weak inferential support regarding regions with one or fewer assessments. Our extrapolation suggests that 4.5%–6.5% of stocks defined by landings data are collapsed, but that this proportion is increasing. Finally, we propose a research agenda that combines stock assessment and landings databases while overcoming limitations in each.
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Wang, Yi Xuan, et Lei Huang. « Research on Numerical Model for Earthquake Induced Progressive Collapse of High-Rise Buildings ». Applied Mechanics and Materials 716-717 (décembre 2014) : 223–26. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.223.

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Progressive collapse is defined as the collapse of the whole building due to local weak stories or weak zones. In this paper, collapse should theoretically be avoided for any building under any earthquake, it is necessary to study the collapse behavior of buildings to acquire a better understanding of the collapse mechanism and to find efficient methods to prevent it. The collapse process highly depends on the feature of the whole structural system, so numerical simulation becomes a major method to study it. Based on the finite element method, by selecting the appropriate cell death and cell contact algorithm criterion can better simulate the structure collapsed in an earthquake under the continuity of the whole process of destruction, to help understand the causes and mechanism of structural damage. The real buildings are analyzed to study the failure mechanism of the structure. The models proposed are reasonable to study the seismic collapse mechanism of high-rise buildings.
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DEL POPOLO, ANTONINO. « IMPROVEMENTS TO THE SPHERICAL COLLAPSE MODEL ». International Journal of Modern Physics D 15, no 07 (juillet 2006) : 1067–88. http://dx.doi.org/10.1142/s0218271806008553.

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We study the joint effect of dynamical friction, tidal torques and cosmological constant on clusters of galaxy formation. We show that within high-density environments, such as rich clusters of galaxies, both dynamical friction and tidal torques slow down the collapse of low-ν peaks producing an observable variation in the time of collapse of the perturbation and, as a consequence, a reduction in the mass bound to the collapsed perturbation. Moreover, the delay of the collapse produces a tendency for less dense regions to accrete less mass, with respect to a classical spherical model, inducing a biasing of over-dense regions toward higher mass. We show how the threshold of collapse is modified if dynamical friction, tidal torques and a non-zero cosmological constant are taken into account and we use the Extended Press–Schecter (EPS) approach to calculate the effects on the mass function. Then, we compare the numerical mass function given in D. Reed, Mon. Not. R. Astron. Soc.346, 565 (2003) with the theoretical mass function obtained in the present paper. We show that the barrier obtained in the present paper gives rise to a better description of the mass function evolution with respect to other previous models, R. K. Sheth and G. Tormen, Mon. Not. R. Astron. Soc.308, 119 (1999) and R. K. Sheth and G. Tormen, Mon. Not. R. Astron. Soc.329, 61 (2002).
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Xu, Qinghu, Xuezhi Zhen, Yu Zhang, Mengjun Han et Wenkang Zhang. « Numerical Simulation Study of Progressive Collapse of Reinforced Concrete Frames with Masonry Infill Walls under Blast Loading ». Modelling and Simulation in Engineering 2022 (11 novembre 2022) : 1–16. http://dx.doi.org/10.1155/2022/1781415.

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The influence of masonry infill walls on the progressive collapse performance of reinforced concrete (RC) frame structures was investigated in this paper, using a nonlinear dynamic analysis approach. Based on ANSYS/LS-DYNA finite element software, two finite element models of RC frame structures with and without masonry infilled walls were established. Then, the collapse modes of the two RC frame structure models were analyzed for different scaled distance blast loads, different locations of column damage, and different span numbers. The results show that with the increase of explosive amount, the collapse degree of the structure is more serious in the same time. Under the condition of destroying the outermost central column, the degree of progressive collapse of the RC frame model with infilled walls in the same time is lower than that of the RC frame model without infilled walls. The RC frame model with infilled walls is more resistant to collapse when the outermost side columns are damaged. With the increase of span number, the structure is more likely to be damaged and collapsed.
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Xie, Kai Zhong, Guang Qiang Chen et Li Lin Wei. « A Damage Model for Collapse-Mechanism of Long-Span and High-Pier Continuous Rigid Frame Bridges ». Advanced Materials Research 219-220 (mars 2011) : 1431–35. http://dx.doi.org/10.4028/www.scientific.net/amr.219-220.1431.

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Collapse-mechanism analysis can simulate that bridges enter strong elasto-plastic and large displacement response and collapses phase, so that it is very important for the seismic design of bridges. In this paper, a damage model of reinforced concrete is introduced, and dynamic response and collapse of long span and high-pier continuous rigid frame bridge during strong earthquake is studied with damage model of reinforced concrete by the explicit dynamic analysis code (LS-DYNA). The simulation results indicate the development of the concrete elements from cracking to failure and the bridge from part collapse to the whole collapse of the bridge are studied. The damage and collapse mechanisms during strong earthquake are given of Long Span and High-pier Continuous Rigid Frame Bridges. References are provided for seismic analysis of this kind of bridges.
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Akbari, Amir, Reghan J. Hill et Theo G. M. van de Ven. « An elastocapillary model of wood-fibre collapse ». Proceedings of the Royal Society A : Mathematical, Physical and Engineering Sciences 471, no 2179 (juillet 2015) : 20150184. http://dx.doi.org/10.1098/rspa.2015.0184.

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An elastocapillary model for drying-induced collapse is proposed. We consider a circular elastic membrane with a hole at the centre that is deformed by the capillary pressure of simply and doubly connected menisci. The membrane overlays a cylindrical cavity with rigid walls, trapping a prescribed volume of water. This geometry may be suitable for studying structural failures and stiction in micro-electromechanical systems during wet etching, where capillary surfaces experience catastrophic transitions. The dry state is determined using the dihedral-angle and volume-turning-point stability criteria. Open and collapsed conformations are predicted from the scaled hole radius, cavity aspect ratio, meniscus contact angle with the membrane and cavity walls, and an elastocapillary number measuring the membrane stretching rigidity relative to the water surface tension. For a given scaled hole radius and cavity aspect ratio, there is a critical elastocapillary number above which the system does not collapse upon drying. The critical elastocapillary number is weakly influenced by the contact angle over a wide range of the scaled hole radius, thus indicating a limitation of surface hydrophobization for controlling the dry-state conformation. The model is applied to the drying of wood fibres above the fibre saturation point, determining the conditions leading to collapse.
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Huang, Sheng Nan, Xin Zheng Lu et Lie Ping Ye. « A Hysteretic Model of Conventional Steel Braces and an Analysis of the Collapse Prevention Effect of Brace Strengthening ». Applied Mechanics and Materials 174-177 (mai 2012) : 3–10. http://dx.doi.org/10.4028/www.scientific.net/amm.174-177.3.

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A hysteretic model of conventional steel braces consisting of 18 parameters is proposed. This model is able to simulate the hysteretic behavior of conventional steel braces accurately. The collapse-prevention strengthening effect with steel braces for a typical reinforced concrete (RC) frame that was close to the epicenter and collapsed during the Great Wenchuan Earthquake is discussed via push-over analysis and collapse fragility analysis based on incremental dynamic analysis. The result could be referred to for the seismic collapse prevention design of RC frames.
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Thèses sur le sujet "Collapse model"

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Herbauts, Isabelle Manon. « Causal wave function collapse model ». Thesis, Queen Mary, University of London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427988.

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Plunkett, J. William (James William Jr ). « The Roman Pantheon : scale-model collapse analyses ». Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107867.

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Thesis: S.M. in Building Technology, Massachusetts Institute of Technology, Department of Architecture, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 27-31).
The Roman Pantheon is among the largest unreinforced masonry dome ever built and is an unparalleled example of the construction capabilities of the ancient Romans. As one of the most well-known buildings in the world, its preservation remains important because of its cultural and societal significance, and the methods used to assess the safety of historic masonry structures continue to be developed, particularly for three-dimensional vaulted forms. Through a study of the Roman Pantheon, this thesis compares analytical and experimental results on a 1:100 scale model of the variable thickness, hemispherical dome. The model is created using additive manufacturing for accuracy. This thesis, using a physical scale model, quantifies the safety of the Roman Pantheon against the two most probable causes of collapse (i) deformation of the building geometry and (2) seismic activity. The structural behavior of the model is compared to analytical predictions of (1) spreading supports, simulating leaning walls that result from the dome thrust or settling of the foundations, and (2) tilting, a first-order approximation of horizontal ground acceleration. The experimental tests lead to the formation of a mechanism and collapse due to instability. High-speed imagery captures the observed collapse mechanisms and failure limits. Experimental results are compared to analytical predictions for hemispherical masonry domes. The results of the physical experiment demonstrate the potential for digitally fabricated scale models in approximating the behavior of three-dimensional structures with complex geometries. The low cost and rapid approach provides a useful method for validating analytical predictions of the limit states and collapse mechanisms of unreinforced masonry structures.
by J. William Plunkett.
S.M. in Building Technology
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Morone, Daniel Justin Reese. « Progressive Collapse : Simplified Analysis Using Experimental Data ». The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354602937.

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Wang, Joseph Chen-yu. « A one dimensional model of convection in iron core collapse supernovae / ». Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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Monasterios, Perez Karin. « Structural adjustment and the collapse of the Bolivian model of accumulation ». Ottawa, 1994.

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Christenson, Michael P. « Black Spaghetti : A Numerical Model of Gravitational Collapse in 4 + 1 Spacetime ». Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd907.pdf.

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Akah, Ebiji Anthony. « Experimental and Analytical Collapse Evaluation of an Existing Building ». The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437620552.

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Vandamme, Johan Richard. « Novel particle model for the prediction of stability and episodic collapse of coastal cliffs and levees ». Thesis, University of Plymouth, 2012. http://hdl.handle.net/10026.1/1027.

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This thesis investigates the WCSPH model by considering fluid entry and exit, and integrates the WCSPH method into a new, novel, particle-based Bluff Morphology Model (BMM). Using the BMM, this thesis investigates the stability, collapse and equilibrium position of soft coastal bluffs (cliffs). Fluid and floating object interaction using a novel adaptation of the WCSPH method is investigated by incorporating a floating object model. In particular, this thesis examines the water impact, hydrodynamic forces, fluid motions, and movement of objects in the conventional case studies of object entry and exit from still water. A two-dimensional wedge drop analysis was examined, and the hydrodynamic forces show acceptable agreement with published experimental and numerical results. Simulations for water entry and exit of a buoyant and neutral density cylinder compares well with the previous experimental, numerical and empirical studies. These results provide a good foundation to evaluate the accuracy and stability of WCSPH for modelling complex flows, and therefore offers a platform for the use of WCSPH in a Bluff Morphology Model. The BMM combines a multiple wedge displacement method with an adapted Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) method. At first the wedge method is applied to compute the stability of the bluff. Once the critical failure mechanism of the bluff slope has been identified, if the Factor of Safety for the mechanism is less than 1, the adapted WCSPH method is used to predict the failure movement and residual shape of the slope. The model is validated against benchmark test cases of bluff stability for purely frictional, purely cohesive, and mixed strength bluff materials including 2D static water tables. The model predictions give a good correlation with the expected values, with medium resolution models producing errors of typically less than 2.0%. In addition, the prediction of lateral movement of a surveyed cliff and the dynamic collapse of a vertical bluff are computed, and compare well with published literature. This model is further extended to then investigate the effect of two dimensional seepage on the stability and collapse of soil slopes and levees. To incorporate the seepage in the model, Darcy’s Law is applied to the interactions among neighbouring soil particles and ghost particles are introduced along the enclosed soil boundary to ensure that no fluid crosses the boundary. The contribution of partially saturated soils and matric suction, as well as the change in hydraulic conductivity due to seepage, are predicted well by this model. The predicted time evolution of slope stability and seepage induced collapse are in reasonable agreement with the experimental results for homogeneous frictional sand and multiple layered cohesive soils. Rapid drawdown over a sand soil is also investigated, and the location and time of the levee collapse occurrence are captured well. A toe erosion model is incorporated within the numerical model, and the location and quantity of erosion caused by lateral seepage is well predicted. The interplay of erosion, seepage and slope instability is examined.
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Corral, Jofré Gonzalo Andrés. « Re-analysis of deep excavation collapse using a generalized effective stress soil model ». Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/60759.

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Thesis (Civ. E.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 137-138).
This thesis re-analyzes the well-documented failure of a 30m deep braced excavation underconsolidated marine clay. Prior analyses of the collapse of the Nicoll Highway have relied on simplified soil models with undrained strength parameters based on empirical correlations and piezocone penetration data. In contrast, the current research simulates the engineering properties of the key Upper and Lower Marine Clay units using a generalized effective stress soil model, MIT-E3, with input parameters calibrated using laboratory test data obtained as part of the post-failure site investigation. The model predictions are evaluated through comparisons with monitoring data and through comparisons with results of prior analyses using the Mohr-Coulomb (MC) model. The MIT-E3 analyses provide a modest improvement in predictions of the measured wall deflections compared to prior MC calculations and give a consistent explanation of the bending failure in the south diaphragm wall and the overloading of the strut-waler connection at the 9th level of strutting. The current analyses do not resolve uncertainties associated with performance of the JGP rafts, movements at the toe of the north-side diaphragm wall or discrepancies with the measured strut loads at level 9. However, they represent a significant advance in predicting excavation performance based directly on results of laboratory tests compared to prior analyses that used generic (i.e., non site-specific) design isotropic strength profiles.
by Gonzalo Andrés Corral Jofré.
Civ.E.
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Gambarotto, Pietro. « Formation of dark matter halos. Statistics and dynamics of the ellipsoidal collapse model ». Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3424900.

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In the standard cosmological model the formation of cosmic structures is described by the collapse of density perturbations. These perturbations have grown by the action of gravity from small Gaussian initial fluctuations. In a ΛCDM Universe cosmic structures formation is driven by the collapse of dark matter,leading to the creation of virialized systems,called dark matter halos. Baryonic matter follows the dark matter potential wells, where it cools transforming its kinetic energy into thermic energy, eventually forming visible systems, stars and galaxies (White and Rees 1978; Blumenthal et al. 1984). Structures then grow hierarchically, from smaller to larger ones. Therefore, halos containing large galaxies are formed through repeated merger of smaller halos. The collapse and subsequent formation of dark matter halos is due only to gravity, so it is simpler to explain compared to the formation of stars and galaxies themselves. However, the problem involves a high number offluid-like particles, and does not admit an analytical solution. Therefore it is better studied through use of N-body numerical simulations. This technique allows to evolve a large number of particles subject only to their mutual gravitational interaction. In this way we can simulate a region of Universe, analyse the motion of particles and the formation of bound structures. The present thesis has the following structure: • Chapter1:We present the standard cosmological model for the formation of cosmic structures, and briefly describe the statistical properties of linear perturbation fields and the growth of linear perturbation in the light of Jeans’ theory. • Chapter 2: We describe the analytical approaches to the study of perturbations in the non linear regime. First of all we present the Zel’dovich approximation in case of a quasi-linear regime, and two main dynamical models: spherical and ellipsoidal collapse. Later we describe two analytic approaches to determine halo statistics starting from the initial fluctuation field: the excursion sets approach and the peaks formalism. We also briefly describe some attempts to merge the two approaches together. • Chapter 3: We describe the main approach to the study of non linear and bound structures: N-body simulations. We also describe the main features of simulations employed in this work. Finally we describe the main properties of dark matter halos, focussing on the contributions of N-body simulation to the study of halo properties. • Chapter 4: Firstly we describe different halo identification methods and relaxation criteria and we explain the choice adopted in this work. Later we describe how we calculate the parameters of the ellipsoidal collapse model starting from the eigenvalues of the deformation tensor smoothed on different scales. At a later stage we present a method to describe the distribution of halo formation time separating the contribution of relaxed and non relaxed halos. • Chapter 5: We explain our peaks identification algorithm and present a statistic of peaks identified in our simulations. We study the correlation functions between protohalo centres of mass, and peaks of different quantities. At a later stage we present an alternative to the peaks model for halo formation. In fact, spherical and ellipsoidal collapse model are missing a dipole term which is present in perturbation theory. We study the points where initial dipole vanishes and we correlate them to the protohalo mass centres. • Chapter 6: In the first part we present a statistic of Lagrangian parameters, and compare it with results obtained by other authors. Afterwards we investigate the correlation between the Lagrangian parameters δL and qL and the halo formation redshift z50 as a function of rescaled mass ν and identification redshift zid. • Chapter 7: Whereas in the previous chapter we described Lagrangian parameters, here we present profiles. Firstly we build Lagrangian profiles around the protohalo mass centres, and show how they correlate with Lagrangian shear and halo formation times. Later we study the relation between Lagrangian and (Eulerian) profile, and show how Lagrangian shear and formation times affect the final halo profiles. Finally we study the evolution of halo particle profiles with time.
Nel quadro del modello cosmologico standard, la formazione delle strutture è descritta attraverso il collasso di perturbazioni di densità con una distribuzione iniziale generalmente assunta come gaussiana. Queste fluttuazioni erano inizialmente piccole e sono cresciute successivamente per effetto della gravità. In un universo ΛCDM la formazione delle strutture cosmiche è guidata dal collasso della materia oscura che porta alla formazione di aloni virializzati. La materia barionica cade dentro alle buche di potenziale create da questi aloni, si raffredda e conduce alla formazione di stelle e galassie, trasformando la sua energia cinetica in energia termica (White and Rees 1978; Blumenthal et al. 1984). Successivamente, le strutture crescono in modo gerarchico, dalle più piccole alle più grandi. Quindi, aloni contenenti galassie massicce si formano tramite l’accrescimento di aloni più piccoli da parte dell’alone principale. Il collasso e la successiva formazione di aloni di materia oscura è dovuto unicamente alla gravità; per questo motivo la sua descrizione è semplice in linea di principio e coinvolge un alto numero di particelle. Un modo efficace di analizzare la formazione di questi aloni passa per l’utilizzo di simulazioni a N corpi. Con questo approccio non si ricerca una soluzione analitica, bensì viene fatto evolvere un gran numero di particelle soggette alla sola interazione gravitazionale. È così possibile simulare una regione di universo e analizzare il moto delle particelle e la formazione di strutture collassate. La struttura di questo lavoro è la seguente: • Capitolo 1: Presentiamo il modello cosmologico standard per la formazione delle strutture cosmiche e descriviamo brevemente le proprietà statistiche dei campi di fluttuazionelinearielacrescitadiperturbazionilineariallalucedellateoriadiJeans. • Capitolo 2: Descriviamo i principali approcci analitici allo studio delle perturbazioni in regime non lineare. Prima di tutto presentiamo l’approssimazione di Zel’dovich applicabile al caso di un regime quasi lineare. e descriviamo i due principali modelli dinamici per lo studio del collasso delle strutture: il modello di collasso sferico e il modello di collasso ellissoidale. Più avanti descriviamo due approcci analitici per la determinazione la statistica degli aloni a partire dal campo di fluttuazioni iniziale: il modello degli excursion sets e il formalismo dei picchi. Descriviamo anche brevemente alcuni tentativi di fondere assieme questi due approcci. • Capitolo 3: Descriviamo il metodo principale utilizzato per lo studio di strutture fortemente non lineari: le simulazioni a N corpi. Descriviamo inoltre le caratteristiche principali delle simulazioni numeriche utilizzate in questo lavoro. Infine, descriviamo le proprietà principali degli aloni di materia oscura, concentrandoci sul contributo dato a questo campo dalle simulazioni numeriche. • Capitolo 4: Inizialmente descriviamo i diversi metodi per l’identificazione di aloni e i criteri di rilassamento usati in questo lavoro. Successivamente descriviamo come sono stati calcolati i parametri del collasso ellissoidale a partire dagli autovalori del tensore di deformazione smussati su diverse scale. L'ultima sezione del capitolo è infine dedicata allo studio di una descrizione della distribuzione dei tempi di formazione dei soli aloni rilassati. • Capitolo 5: Descriviamo il metodo usato per l’identificazione dei picchi nei campi iniziali e presentiamo una descrizione statistica dei picchi suddetti. Successivamente analizziamo la funzione di correlazione tra i centri di massa dei protoaloni e i picchi e le valli nella distribuzione dei parametri di interesse. L'ultima parte del capitolo è dedicata all'analisi di un’alternativa al formalismo dei picchi per l’identificazione della formazione degli aloni. Infatti, il collasso sferico e quello ellissoidale mancano di un termine di dipolo presente invece nella teoria delle perturbazioni. Studiamo dunque i punti dove il dipolo iniziale svanisce e li relazioniamo ai centri di massa dei protoaloni. • Capitolo 6: Nella prima parte presentiamo una descrizione statistica dei parametri Lagrangiani, svolgendo un opportuno confronto coi risultati di altri autori. Successivamente indaghiamo la correlazione tra i parametri lagrangiani δL e qL e i redshift di formazione degli aloni z50 in funzione della massa universale ν e del redshift di identificazione. • Capitolo 7:Mentre nel precedente capitolo abbiamo descritto parametri smussati su una sola scala, la scala lagrangiana degli aloni, passiamo ora all’analisi dei profili. Primariamente costruiamo i profili lagrangiani attorno al centro di massa dei protoaloni e mostriamo come correlano con il parametro di shear e il redshift di formazione. Successivamente studiamo la relazione tra i profili lagrangiani e i profili euleriani e mostriamo che l’effetto dello shear lagrangiano e del tempo di formazione ancora presente nei profili finali. Infine studiamo l’evoluzione dei profili delle particelle dell’alone a diversi tempi cosmici.
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Livres sur le sujet "Collapse model"

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Peadar, Kirby, dir. Celtic tiger in collapse : Explaining the weaknesses of the Irish model. 2e éd. New York : Palgrave Macmillan, 2010.

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Falzon, Brian G. An introduction to modelling buckling and collapse. Glasgow : NAFEMS, 2006.

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Garber, Peter M. The operation and collapse of fixed exchange rate regimes. Cambridge, MA : National Bureau of Economic Research, 1994.

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Garber, Peter M. The operation and collapse of fixed exchange rate regimes. Cambridge, Mass : National Bureau of Economic Research, 1994.

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Garber, Peter M. The operation and collapse of fixed exchange rate regimes. Stockholm : Stockholm University, Institute for International Economic Studies, 1995.

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Dolinskai︠a︡, Irina. Explaining Russia's output collapse : Aggregate sources and regional evidence. [Washington, D.C.] : International Monetary Fund, IMF Institute, 2001.

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Emergence and collapse of early villages : Models of central mesa verde archaeology. Berkeley : University of California Press, 2012.

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The dynamics of apocalypse : A systems simulation of the classic Maya collapse. Albuquerque : University of New Mexico Press, 1985.

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Fibich, Gadi. Backscattering and nonparaxiality arrest collapse of damped nonlinear waves. Hampton, VA : Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 2002.

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W, Cooper Russell. Financial collapse and active monetary policy : A lesson from the Great Depression. [Minneapolis, Minn.] : Federal Reserve Bank of Minneapolis, 2001.

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Chapitres de livres sur le sujet "Collapse model"

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Kirby, Peadar. « Introduction : The Collapse of the Irish Model ». Dans Celtic Tiger in Collapse, 1–10. London : Palgrave Macmillan UK, 2010. http://dx.doi.org/10.1057/9780230278035_1.

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Blakemore, Philip. « A Theoretical Model of Collapse Recovery ». Dans Delamination in Wood, Wood Products and Wood-Based Composites, 101–19. Dordrecht : Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-9550-3_5.

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Rodopoulos, C. A. « Collapse Stress and the Dugdale’s Model ». Dans Problems of Fracture Mechanics and Fatigue, 597–99. Dordrecht : Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_131.

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Jia, Menghao, Fanyi Zhang, Xinyi Lyu, Yuncheng Wen et Hua Xu. « Three-Dimensional Hydrodynamic Analysis and Early Warning of Ω-Collapse in the Lower Reaches of the Yangtze River Based on Experimental Study on Generalized Model ». Dans Lecture Notes in Civil Engineering, 1589–603. Singapore : Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6138-0_140.

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AbstractUnder the background of the construction of cascade reservoir group in the main stream of the Yangtze River, the lower reaches of the Yangtze River are faced with new water and sediment situation, which leads to the increased risk of bank collapse in the lower reaches of the Yangtze River. Therefore, the purpose of this study is to have a certain supporting significance for the prevention and control of riverbank collapse disasters. The study takes the Jiangsu section of the lower reaches of the Yangtze River as the research object. Firstly, according to the measured data over the years, the macroscopic characteristics of the collapsed bank in the Jiangsu section are analyzed, and the temporal and spatial distribution characteristics are mainly analyzed. The research results show that the collapse of the Jiangsu section of the Yangtze River is dominated by Ω-collapse, which mostly occurs in the flood season and the post-flood receding water period. The frequency of bank collapse in the Yangzhong Reach is relatively the highest among all river segments, and there are more bank collapses on the north bank than the south bank. According to statistics, the average collapse width of the collapse in the Jiangsu section can reach 130 m, the depth of the collapse can reach 60 m, and the ratio of the average bank collapse to the depth can reach 2.15. Then, aiming at the characteristics of the main bank collapse type in the Jiangsu section is the Ω-collapse, the experimental investigation and numerical calculation are used to conduct in-depth research, combined with the measured data, probability and statistical analysis and theoretical analysis. Three-dimensional hydrodynamic analysis is carried out on the mainstream area near the collapse area and outside the collapse area, focusing on the analysis of its nearshore velocity and shear stress and other factors. Combined with the water tank test, the water flow in the inner surface, middle and bottom layers of the Ω-type nest was studied under different flow levels, and it was concluded that the water flow in the nest had a counterclockwise backflow, and the backflow intensity gradually weakened from the side wall to the center. And the phenomenon that the surface layer and the bottom water flow are separated, and this phenomenon becomes more prominent with the increase of the flow rate.
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Masunaga, Hirohiko, S. Inutsuka et S. M. Miyama. « A Radiation Hydrodynamical Model for Protostellar Collapse ». Dans Numerical Astrophysics, 169–70. Dordrecht : Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-011-4780-4_52.

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Gorman, Michael E. « Cognition, Environment and the Collapse of Civilizations ». Dans Model-Based Reasoning in Science, Technology, and Medicine, 217–27. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71986-1_12.

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Zhu, Ruifang, et Wei Shen. « Edge Collapse Considering Triangular Mesh for Model Simplification ». Dans Proceedings of The Eighth International Conference on Bio-Inspired Computing : Theories and Applications (BIC-TA), 2013, 1175–81. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37502-6_137.

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Aschheim, Joseph, Costas Christou, P. A. V. B. Swamy et George S. Tavlas. « A Random Coefficient Model of Speculative Attacks : The Case of the Mexican Peso ». Dans The Collapse of Exchange Rate Regimes, 123–41. Boston, MA : Springer US, 1996. http://dx.doi.org/10.1007/978-1-4615-6289-4_8.

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Tomoaia-Cotişel, Maria, J. Zsako, E. Chifu, D. A. Cadenhead et H. E. Ries. « Collapse Mechanism of some Carotenoid Monomolecular Films - Membrane Model ». Dans Progress in Photosynthesis Research, 333–37. Dordrecht : Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3535-8_81.

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Zhang, Yan, Guoshao Su et Liubin Yan. « Gaussian Process Machine Learning Model for Forecasting of Karstic Collapse ». Dans Communications in Computer and Information Science, 365–72. Berlin, Heidelberg : Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-23214-5_48.

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Actes de conférences sur le sujet "Collapse model"

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Liu, Zhiqiang, et Qing Huang. « Market Competition and Stock Collapse Risk ». Dans 2019 International Conference on Economic Management and Model Engineering (ICEMME). IEEE, 2019. http://dx.doi.org/10.1109/icemme49371.2019.00016.

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STOITCHEVA, G., et D. J. DEAN. « SHELL MODEL OF NUCLEI FOR STELLAR CORE COLLAPSE : CURRENT STATUS, FUTURE PROSPECTS ». Dans Open Issues in Core Collapse Supernova Theory. WORLD SCIENTIFIC, 2005. http://dx.doi.org/10.1142/9789812703446_0012.

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Lundgren, T. S., et D. D. Joseph. « Symmetric Model of Capillary Collapse and Rupture (Keynote) ». Dans ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37262.

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The breakup of a liquid capillary filament is analyzed as a viscous potential flow near a stagnation point on the centerline of the filament towards which the surface collapses under the action of surface tension forces. The analysis given her is restricted to cases in which the neckdown is symmetric around the stagnation point. We find that the neck is of parabolic shape and its radius collapses to zero in a finite time; the curvature at the throat tends to zero much faster than the radius, leading ultimately to a microthread of nearly uniform radius. During the collapse the tensile stress due to viscosity increases in value until at a certain finite radius, which is about 1.5 microns for water in air, the stress in the throat passes into tension, presumably inducing cavitation there.
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Buscemi, Nanci, et Shalva Marjanishvili. « SDOF Model for Progressive Collapse Analysis ». Dans Structures Congress 2005. Reston, VA : American Society of Civil Engineers, 2005. http://dx.doi.org/10.1061/40753(171)221.

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Savoia, Alessandro S., Omid Farhanieh et Bruno Haider. « A Large-Signal Nonlinear Equivalent Circuit Model for CMUTs Operating in Collapse and Non-Collapse Modes ». Dans 2022 IEEE International Ultrasonics Symposium (IUS). IEEE, 2022. http://dx.doi.org/10.1109/ius54386.2022.9957850.

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Brechan, Bjorn, Even Kornberg, Sigbjorn Sangesland et Stein Inge Dale. « Well Integrity Model - Klever & ; Tamano Collapse ». Dans SPE/IADC Middle East Drilling Technology Conference and Exhibition. Society of Petroleum Engineers, 2018. http://dx.doi.org/10.2118/189395-ms.

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Tsukada, H., M. DeCamp, CR O'Donnell, D. Litmanovich, R. Garland et A. Ernst. « A Sheep Model for Hyperdynamic Central Airway Collapse. » Dans American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a5782.

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Alashker, Yasser, et Sherif El-Tawil. « Design Model for Collapse Capacity of Composite Floors ». Dans Structures Congress 2010. Reston, VA : American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41130(369)106.

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Zheng, Xin, Hairong Yan, Xiao Gao et Yubo Tu. « AWFMFNet image classification network model for concrete collapse ». Dans 2022 IEEE 5th Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC). IEEE, 2022. http://dx.doi.org/10.1109/imcec55388.2022.10020095.

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Babaei, M. H. « Collapse of Rectangular Granular Piles in Air and Water ». Dans ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-65012.

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Granular materials are processed in many industries including agricultural, pharmaceutical, mining, and oil-sand and several geophysical processes such as landslides and avalanches. There are few models capable of predicting the flow of granular materials and particularly their collapse. Theoretical studies of the topic usually encounter difficulties in accurately predicting the collapse dynamics and final stable heaps. The two-dimensional gravitational collapse of cohesionless rectangular granular piles is numerically investigated in this paper. Piles surrounded by either air (dry case) or an oil-water mixture (wet case) undergo a dam-break collapse onto a horizontal base. The granular material is modeled as a perfectly plastic substance based on the Mohr-Coulomb law. The constitutive relations represent the granular material as a fluid, with a shear viscosity as a function of solids pressure, the second invariant of the deviatoric strain-rate tensor, and the internal angle of friction of the granular material. This two-phase flow problem (grains and liquid or air) is then formulated accordingly and solved by the mixture model method for the wet collapse and the level-set method for the dry collapse using COMSOL finite-element software. In both air and the liquid, stable heaps are achieved. The results are compared with experimental measurements of Balmforth & Kerswell [1] and Rondon et al. [2]. The model can closely predict the final shape of the collapsed dry pile. The final shape of the collapsed wet pile is also well-predicted when its initial packing concentration is relatively low. Further developments are needed to model the wet collapse of high-initial-concentration piles.
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Rapports d'organisations sur le sujet "Collapse model"

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Woodson, Stanley C., et James T. Baylot. Structural Collapse : Quarter-Scale Model Experiments. Fort Belvoir, VA : Defense Technical Information Center, août 1999. http://dx.doi.org/10.21236/ada369355.

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G. Li et C. Tsang. Seepage Model for PA Including Dift Collapse. Office of Scientific and Technical Information (OSTI), décembre 2000. http://dx.doi.org/10.2172/840689.

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C. Tsang. SEEPAGE MODEL FOR PA INCLUDING DRIFT COLLAPSE. Office of Scientific and Technical Information (OSTI), septembre 2004. http://dx.doi.org/10.2172/841253.

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McHardy, James. Development of a Cavity Collapse Model of Cavitation Bubbles in Water in One and Two Dimensions using the Finite Volume FLAG Hydrocode at Atmospheric Pressure and 293K. Office of Scientific and Technical Information (OSTI), juin 2014. http://dx.doi.org/10.2172/1136106.

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Adler, R. Simple Analytic Models of Gravitational Collapse. Office of Scientific and Technical Information (OSTI), février 2005. http://dx.doi.org/10.2172/839752.

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Terzic, Vesna, et William Pasco. Novel Method for Probabilistic Evaluation of the Post-Earthquake Functionality of a Bridge. Mineta Transportation Institute, avril 2021. http://dx.doi.org/10.31979/mti.2021.1916.

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While modern overpass bridges are safe against collapse, their functionality will likely be compromised in case of design-level or beyond design-level earthquake, which may generate excessive residual displacements of the bridge deck. Presently, there is no validated, quantitative approach for estimating the operational level of the bridge after an earthquake due to the difficulty of accurately simulating residual displacements. This research develops a novel method for probabilistic evaluation of the post-earthquake functionality state of the bridge; the approach is founded on an explicit evaluation of bridge residual displacements and associated traffic capacity by considering realistic traffic load scenarios. This research proposes a high-fidelity finite-element model for bridge columns, developed and calibrated using existing experimental data from the shake table tests of a full-scale bridge column. This finite-element model of the bridge column is further expanded to enable evaluation of the axial load-carrying capacity of damaged columns, which is critical for an accurate evaluation of the traffic capacity of the bridge. Existing experimental data from the crushing tests on the columns with earthquake-induced damage support this phase of the finite-element model development. To properly evaluate the bridge's post-earthquake functionality state, realistic traffic loadings representative of different bridge conditions (e.g., immediate access, emergency traffic only, closed) are applied in the proposed model following an earthquake simulation. The traffic loadings in the finite-element model consider the distribution of the vehicles on the bridge causing the largest forces in the bridge columns.
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Baader, Franz, et Cesare Tinelli. Combining Equational Theories Sharing Non-Collapse-Free Constructors. Aachen University of Technology, 1999. http://dx.doi.org/10.25368/2022.103.

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In a previous work, we describe a method to combine decision procedures for the word problem for theories sharing constructors. One of the requirements of our combination method is that constructors be collapse-free. This paper removes that requirement by modifying the method so that it applies to non-collapse-free constructors as well. This broadens the scope of our combi- nation results considerably, for example in the direction of equational theories corresponding to modal logics.
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Peters, C. Mechanical test results on Dipole model C-1 25 mm aluminum collars. Office of Scientific and Technical Information (OSTI), février 1985. http://dx.doi.org/10.2172/5224978.

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Wolfe, S. A., H. B. O'Neill, C. Duchesne, D. Froese, J M Young et S. V. Kokelj. Ground ice degradation and thermokarst terrain formation in Canada over the past 16 000 years. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329668.

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Thermokarst results from thawing of excess ground ice in permafrost sediments. Thermokarst processes and landforms are controlled by ground ice type, amount and distribution, as well as the patterns of ground ice loss over time. Recent acceleration of varied thermokarst processes across diverse Canadian permafrost terrains make for a challenging task in predicting landscape-scale thaw trajectories. Using existing ground ice models, we examined the modelled amounts and spatial extent of ground ice loss relative to ground ice maxima in the last ca. 16 ka BP for relict, segregated and wedge ice. We relate observed thermokarst features to the nature of ground ice development and loss in different environments (cold continuous permafrost, discontinuous permafrost, and no current permafrost). In cold, continuous permafrost areas where ground ice loss has been limited over the last 16 ka BP, thermokarst processes include active layer detachments and slumps in segregated and relict ice, gullying and ponding in ice wedge troughs, and the cyclical development of shallow thermokarst ponds in segregated ice. With ground ice loss in discontinuous permafrost, thermokarst processes are wide-ranging. Slumps, subsidence, and collapse of lithalsas, palsas and peat plateaus occur from thawing of segregated ice, thermokarst ponds from melting wedge and segregated ice, and involuted terrain from melting and creep of relict or segregated ice. In former permafrost terrain, evidence of thermokarst includes former ice wedge polygons, collapsed lithalsas, and irregular hummocky terrain. The relations between modelled ground ice loss and observed thermokarst landscapes assist in understanding present-day processes and in predicting future thermokarst landform evolution with a changing climate.
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Gunay, Selim, Fan Hu, Khalid Mosalam, Arpit Nema, Jose Restrepo, Adam Zsarnoczay et Jack Baker. Blind Prediction of Shaking Table Tests of a New Bridge Bent Design. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/svks9397.

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Considering the importance of the transportation network and bridge structures, the associated seismic design philosophy is shifting from the basic collapse prevention objective to maintaining functionality on the community scale in the aftermath of moderate to strong earthquakes (i.e., resiliency). In addition to performance, the associated construction philosophy is also being modernized, with the utilization of accelerated bridge construction (ABC) techniques to reduce impacts of construction work on traffic, society, economy, and on-site safety during construction. Recent years have seen several developments towards the design of low-damage bridges and ABC. According to the results of conducted tests, these systems have significant potential to achieve the intended community resiliency objectives. Taking advantage of such potential in the standard design and analysis processes requires proper modeling that adequately characterizes the behavior and response of these bridge systems. To evaluate the current practices and abilities of the structural engineering community to model this type of resiliency-oriented bridges, the Pacific Earthquake Engineering Research Center (PEER) organized a blind prediction contest of a two-column bridge bent consisting of columns with enhanced response characteristics achieved by a well-balanced contribution of self-centering, rocking, and energy dissipation. The parameters of this blind prediction competition are described in this report, and the predictions submitted by different teams are analyzed. In general, forces are predicted better than displacements. The post-tension bar forces and residual displacements are predicted with the best and least accuracy, respectively. Some of the predicted quantities are observed to have coefficient of variation (COV) values larger than 50%; however, in general, the scatter in the predictions amongst different teams is not significantly large. Applied ground motions (GM) in shaking table tests consisted of a series of naturally recorded earthquake acceleration signals, where GM1 is found to be the largest contributor to the displacement error for most of the teams, and GM7 is the largest contributor to the force (hence, the acceleration) error. The large contribution of GM1 to the displacement error is due to the elastic response in GM1 and the errors stemming from the incorrect estimation of the period and damping ratio. The contribution of GM7 to the force error is due to the errors in the estimation of the base-shear capacity. Several teams were able to predict forces and accelerations with only moderate bias. Displacements, however, were systematically underestimated by almost every team. This suggests that there is a general problem either in the assumptions made or the models used to simulate the response of this type of bridge bent with enhanced response characteristics. Predictions of the best-performing teams were consistently and substantially better than average in all response quantities. The engineering community would benefit from learning details of the approach of the best teams and the factors that caused the models of other teams to fail to produce similarly good results. Blind prediction contests provide: (1) very useful information regarding areas where current numerical models might be improved; and (2) quantitative data regarding the uncertainty of analytical models for use in performance-based earthquake engineering evaluations. Such blind prediction contests should be encouraged for other experimental research activities and are planned to be conducted annually by PEER.
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