World Library  


 
  • Cover Image

An Extension of Conditional Nonlinear Optimal Perturbation Approac...

By: Q. Wang; W. Duan; M. Mu; R. Zhang

Description: Key Laboratory of Ocean Circulation and Wave, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. The approach of conditional nonlinear optimal perturbation (CNOP) was previously proposed to find the optimal initial perturbation (CNOP-I) in a given constraint. In this paper, we extend the CNOP approach to search for the optimal combined mode of initial perturbations and model parameter perturbations. This optimal combined mode, ...

Aanonsen, S. I.: Efficient history matching using a multiscale technique, SPE Reservoir Evaluation and Engineering, 154–164, February 2008.; Birgin, E. G., Martinez, J. M., and Raydan, M.: Nonmonotone spectral projected gradient methods on convex sets, SIAM J. Optimiz., 10, 1196–1211, 2000.; Chu, P. C., Lu, S. H., and Chen, Y. C.: Two kinds of predictability problems in Lorenz system and climate models, Second Hayes Symposium on Seasonal to Interannual Climate Variabilit...

Read More
  • Cover Image

Beyond Multifractional Brownian Motion: New Stochastic Models for ...

By: J. Lévy Véhel

Description: Regularity Team, Inria and MAS Laboratory, Ecole Centrale Paris, Grande Voie des Vignes, Chatenay Malabry, France. Multifractional Brownian motion (mBm) has proved to be a useful tool in various areas of geophysical modelling. Although a versatile model, mBm is of course not always an adequate one. We present in this work several other stochastic processes which could potentially be useful in geophysics. The first alternative type is that of self-reg...

Echelard, A. and Lévy Véhel, J.: Self-regulating processes-based modelling for arrhythmia characterization, in: ISPHT 2012, International Conference on Imaging and Signal Processing in Health Care and Technology, 14–16 May, Baltimore, 2012.; Echelard, A., Barrière, O., and Lévy Véhel, J.: Terrain modelling with multifractional Brownian motion and self-regulating processes, Springer, Lect. Notes Comput. Sc., 6374, 342–351, 2010.; Echelard, A., Lévy Véhel, J., and Philippe...

Read More
  • Cover Image

Avalanches in Bi-directional Sandpile and Burning Models: a Compar...

By: M. Bregman; D. Coca; M. Balikhin; R. A. Treumann; G. Consolini; M. Gedalin

Description: Ben-Gurion University, Beer-Sheva, Israel. We perform a statistical analysis of two one-dimensional avalanching models: the bi-directional sandpile and the burning model (described in detail in the companion paper by Gedalin et al. (2005) Dynamics of the burning model). Such a comparison helps understand whether very limited measurements done by a remote observer may provide sufficient information to distinguish between the two physically different aval...

Read More
  • Cover Image

Scale Free Properties in a Network-based Integrated Approach to Ea...

By: M. Suteanu

Description: Department of Mathematics & Computing Science, Saint Mary's University, Halifax, Canada. This paper proposes a network-based method for the assessment of earthquake relationships in space–time–magnitude patterns. It is shown that networks with high values for the minimum edge weight Wmin enjoy strong scaling properties, as opposed to networks with low values for Wmin, which exhibit no such properties. The scaling behav...

Albert, R. and Barabási, A.-L.: Statistical mechanics of complex networks, Rev. Mod. Phys., 74, 47–97, 2002.; Baiesi, M. and Paczuski, M.: Scale-free networks for earthquakes and aftershocks, Phys. Rev. E, 69, 066106-1–8, 2004.; Baiesi, M. and Paczuski, M.: Complex networks of earthquakes and aftershocks, Nonlin. Processes Geophys., 12, 1–11, doi:10.5194/npg-12-1-2005, 2005.; Bak, P., Christensen, K., Danon, L., and Sca...

Read More
  • Cover Image

Wavelet Analysis in a Structured Clay Soil Using 2-d Images : Volu...

By: A. M. Tarquis; K. J. McInnes; D. Andina; J. A. Piñuela

Description: Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, 28040, Spain. The spatial variability of preferential pathways for water and chemical transport in a field soil, as visualized through dye infiltration experiments, was studied by applying multifractal and wavelet transform analysis (WTA). After dye infiltration into a 4 m² plot located on a Vertisol soil near College Station, Texas, horizontal planes in the subsoil were exposed at 5 cm interv...

Arneodo, A., Grasseau, G., and Holshneider, M.: Wavelet transform of multifractals, Phys. Rev. Lett., 61, 2281–2284, 1988.; Arneodo, A., Bacry, E., and Muzy, J.: Solving the inverse fractal problem from wavelet analysis, Europhysics Lett., 25(7), 479–484, 1994.; Daubechies, I.: Ten lectures on wavelets, volume 61, CBMS conference on wavelets, 1992.; Folorunso, O A., Puente, D E., Rolston, D E., and Pinzon, J E.: Statistical and fractal evaluation of the spatial character...

Read More
  • Cover Image

Searching for Determinism in Observed Data: a Review of the Issues...

By: G. N. Triantafyllou; J. B. Elsner; A. A. Tsonis

Description: Dept. of Geosciences, University of Wisconsin-Milwaukee, WI 53201, USA. In this paper we present a review of advances made and problems still existing in the application of the theory of chaos and dynamical systems to time series. In particular we discuss issues pertaining the estimation of dimensions, Lyapunov exponents and nonlinear prediction from an observable. We analyze the problems and discuss proper ways to deal with them.

Read More
  • Cover Image

Fractal Dimensions of Wildfire Spreading : Volume 21, Issue 4 (07/...

By: S.-p. Li; H.-i. Lee; S.-l. Wang

Description: Institute of Physics, Academia Sinica 128 Sec. 2, Academia Rd., Nankang, Taipei, 11529, Taiwan (ROC). The time series data of 31 wildfires in 2012 in the US were analyzed. The fractal dimensions (FD) of the wildfires during spreading were studied and their geological features were identified. A growth model based on the cellular automata method is proposed here. Numerical study was performed and is shown to give good agreement with the fractal dimensions...

Alexandridis, A., Vakalis, D., Siettos, C. I., and Bafas, G. V.: A cellular automata model for forest fire spread prediction: The case of the wildfire that swept through Spetses Island in 1990, Appl. Math. Comput., 204, 191–201, 2008.; Anderson, D. G., Catchpole, E. A., DeMestre, N. J., and Parkes, E.: Modeling the spread of grass fires, J. Austral. Math. Soc., Series B, 23, 451–466, 1982.; Bak, P., Chen, K., and Tang, C.: A forest-fire model and some thoughts on turbule...

Read More
  • Cover Image

An Intercomparison of Burnt Area Estimates Derived from Key Operat...

By: G. P. Petropoulos; I. M. Athanasiou; V. J. Kollias; D. P. Kalivas

Description: Department of Natural Resources Development and Agricultural Engineering, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece. With the support of new technologies such as of remote sensing, today's societies have been able to map and analyse wildland fires at large observational scales. With regards to burnt area mapping in particular, two of the most widely used operational products are offered today by the United States National Aer...

ASTER GDEM: ASTER GDEM Version, 1. Readme File available at: http://www.gdem.aster.ersdac.or.jp (last access: 24 July 2011), 2009.; Barbosa, P., Kusera, J., Strobl, P., Vogt, P., Camia, A., and San-Miguel-Ayanz, J.: European Forest Fire information System (EFFIS) – rapid damage assessment: appraisal of burnt area maps in southern Europe using MODIS data (2003 to 2005), Forest Ecol. Manage., 232, Supp. 1, pS218, 2006.; Boboul...

Read More
  • Cover Image

Stochastic Formalism-based Seafloor Feature Discrimination Using M...

By: B. Chakraborty; K. Haris

Description: CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India. Dual-frequency echo-envelope data acquired using the normal-incidence single-beam echosounder system (SBES) have been examined to study its scale invariant properties. The scaling and multifractality of the SBES echo envelopes (at 33 and 210 kHz) were validated by applying a stochastic-based multifractal analysis technique. The analyses carried out substantiate the hierarchy of mult...

Amiri-Simkooei, A. R., Snellen, M., and Simons, D. G.: Principal component analysis of single-beam echo-sounder signal features for seafloor classification, IEEE J. Ocean. Eng., 36, 259–271, 2011.; Bak, P., Tang, C., and Wiesenfeld, K.: Self-Organized Criticality: An Explanation of 1/f Noise, Phys. Rev. Lett., 59, 381–384, 1987.; Anderson, J. T., Holliday, D. V., Kloser, R., Reid, D. G., and Simard, Y.: Acoustic seabed classification: current practice and future d...

Read More
  • Cover Image

Models for Strongly-nonlinear Evolution of Long Internal Waves in ...

By: T. Sakai; L. G. Redekopp

Description: Department of Aerospace & Mechanical Engineering, University of Southern California, Los Angeles, CA 90089-1191, USA. Models describing the evolution of long internal waves are proposed that are based on different polynomial approximations of the exact expression for the phase speed of uni-directional, fully-nonlinear, infinitely-long waves in the two-layer model of a density stratified environment. It is argued that a quartic KdV model, one that employ...

Amick, C. and Turner, R.: A global theory of internal waves in two-fluid systems., Trans. Am. Math. Soc., 298, 431–481, 1986.; Apel, J., Holbrook, J., Liu, A., and Tsai, J.: The Sulu Sea internal soliton experiment., J. Phys. Oceanogr., 15, 1625–1651, 1985.; Antenucci, J., Imberger, J., and Saggio, A.: Seasonal evolution of the basin-scale internal wave field in a large stratified lake., Limnol. Oceanogr., 45, 1621–1638, 2000.; Benjamin, T.: Internal waves of finite ampl...

Read More
  • Cover Image

Mfga-idt2 Workshop: Astrophysical and Geophysical Fluid Mechanics:...

By: D. Schertzer; E. Falgarone

Description: Laboratoire de Météorologie Dynamique, Université P. et M. Curie, case 99, 4 Pl. Jussieu, F-75252 Paris Cedex 05, France.

1 Facts about the Workshop

This workshop was convened on November 13-15 1995 by E. Falgarone and D. Schertzer within the framework of the Groupe de Recherche Mecanique des Fluides Geophysiques et Astrophysiques (GdR MFGA, Research Group of Geophysical and Astrophysical Fluid Mechanics) of Centre National de la Recherc...

Read More
  • Cover Image

Brief Communication: Weibel, Firehose and Mirror Mode Relations : ...

By: W. Baumjohann; R. A. Treumann

Description: Department of Geophysics and Environmental Sciences, Munich University, Munich, Germany. Excitation of Weibel magnetic fields in an initially non-magnetized though anisotropic plasma may trigger other low-frequency instabilities fed by pressure anisotropy. It is shown that under Weibel-like stable conditions the Weibel-like thermal fluctuation magnetic field allows for restricted Firehose-mode growth. In addition, low-frequency Whistlers can also propaga...

Landau, L. D. and Lifshitz, E. M.: Electrodynamics of Continuous Media, Pergamon Press, Oxford, 1960.; Achterberg, A. and Wiersma, J.: The Weibel instability in relativistic plasmas. I. Linear theory, II. Nonlinear theory and stabilization mechanism, Astron. Astrophys., 475, 1–18, doi:10.1051/0004-6361:20065365, 2007.; Akhiezer, A. I., Akhiezer, I. A., Sitenko, R. V., and Stepanov, K. N.: Nonlinear Theory and Fluct...

Read More
  • Cover Image

Using Modern Time Series Analysis Techniques to Predict Enso Event...

By: M. Wimbush; J. I. Salisbury

Description: Echo Technology, PO. Box 527, Chepachet, RI, USA. We analyze the monthly 1866-2000 Southern Oscillation Index (SOI) data to determine:

1) whether the SOI data are sufficiently noise-free that useful predictions can be made from them, and

2) in particular, whether future ENSO events can be predicted from the SOI data. 

The "Hilbert-EMD" technique is used to aid the analysis. This new frequency-time algorithm...

Read More
  • Cover Image

Conditional Nonlinear Optimal Perturbation and Its Applications : ...

By: B. Wang; W. S. Duan; M. Mu

Description: LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. Conditional nonlinear optimal perturbation (CNOP) is proposed to study the predictability of numerical weather and climate prediction. A simple coupled ocean-atmosphere model for ENSO is adopted as an example to show its applicability. In the case of climatological mean state being the basic state, it is shown that CNOP tends to evolve into El Niño...

Read More
  • Cover Image

The Karlsruhe Dynamo Experiment : Volume 9, Issue 3/4 (30/11/-0001)

By: U. Müller; R. Stieglitz

Description: It has been shown theoretically in the past that homogeneous dynamos may occur in electrically conducting fluids for various vortical velocity fields. Roberts (1972) investigated spatially periodic, infinitely extended fields of vortices which Busse (1978, 1992) confined to a finite cylindrical domain. Based on Busse's vortex arrangement a conceptual design for an experimental homogeneous dynamo has been developed and a test facility ...

Read More
  • Cover Image

Improving the Ensemble Transform Kalman Filter Using a Second-orde...

By: X. Zheng; G. Wu; X. Zhang; L. Wang; S. Zhang; X. Liang; X. Yi

Description: State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, China. The ensemble transform Kalman filter (ETKF) assimilation scheme has recently seen rapid development and wide application. As a specific implementation of the ensemble Kalman filter (EnKF), the ETKF is computationally more efficient than the conventional EnKF. However, the current implementation of the ETKF still ha...

Anderson, J. L.: An adaptive covariance inflation error correction algorithm for ensemble filters, Tellus A, 59, 210–224, 2007.; Anderson, J. L.: Spatially and temporally varying adaptive covariance inflation for ensemble filters, Tellus A, 61, 72–83, 2009.; Anderson, J. L. and Anderson, S. L.: A Monte Carlo implementation of the non-linear filtering problem to produce ensemble assimilations and forecasts, Mon. Weather Rev., 127, 2741–2758, 1999.; Bishop, C. H. and Toth,...

Read More
  • Cover Image

Plankton Blooms in Vortices: the Role of Biological and Hydrodynam...

By: C. López; E. Hernández-garcía; U. Feudel; M. Sandulescu

Description: Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany. We study the interplay of hydrodynamic mesoscale structures and the growth of plankton in the wake of an island, and its interaction with a coastal upwelling. Our focus is on a mechanism for the emergence of localized plankton blooms in vortices. Using a coupled system of a kinematic flow mimicking the mesoscale structures b...

Abraham, E.: The generation of plankton patchiness by turbulent stirring, Nature, 391, 577–580, 1998.; Ar\'\istegui, J., Tett, P., Hernández-Guerra, A., Basterretxea, G., Montero, M. F., Wild, K., Sangrá, P., Hernández-Leon, S., Canton, M., Garc\'\ia-Braun, J. A., Pacheco, M., and Barton, E.: The influence of island-generated eddies on chlorophyll distribution: a study of mesoscale variation around Gran Canaria, Deep-Sea Res I, 44, 71–96, 1997.; Ar\'\istegui, J., Barton,...

Read More
  • Cover Image

Streamflow Disaggregation: a Nonlinear Deterministic Approach : Vo...

By: W. W. Wallender; B. Sivakumar; M. N. Islam; C. E. Puente

Description: Department of Land, Air and Water Resources, University of California, Davis, USA. This study introduces a nonlinear deterministic approach for streamflow disaggregation. According to this approach, the streamflow transformation process from one scale to another is treated as a nonlinear deterministic process, rather than a stochastic process as generally assumed. The approach follows two important steps: (1) reconstruction of the scalar (streamflow) se...

Read More
  • Cover Image

Spatial Analysis of Oil Reservoirs Using Detrended Fluctuation Ana...

By: L. S. Lucena; U. L. Fulco; M. V. M. Mata; G. Corso; R. A. Ribeiro

Description: Centro Universitário-FACEX-UNIFACEX, Rua Orlando Silva, 2897, Capim Macio, CEP 59080 020, Natal, RN, Brazil. We employ the detrended fluctuation analysis (DFA) technique to investigate spatial properties of an oil reservoir. This reservoir is situated at Bacia de Namorados, RJ, Brazil. The data correspond to well logs of the following geophysical quantities: sonic, gamma ray, density, porosity and electrical resistivity, measured in 56 wells. We tested t...

Andrade, R. F., Oliveira, O., Cardoso, A. L., Lucena, L. S., Leite, F. E. A., Porsani, M. J., and Maciel, R. C.: Exploring self-affine properties in seismograms, Comput. Geosci., 13, 155–163 2009.; Asquith, G. and Krygowski, D.: Basic Well Log Analysis, American Association of Petroleum Geologists, Tulsa, Oklahoma, 2004.; Chun-Feng, L. I. and Liner, C.: Singularity Exponent from Wavelet-Based Multiscale Analysis: A New Seismic Attribute, Chin. J. Geophys., 48, 953–959, 2...

Read More
  • Cover Image

Generation of Weakly Nonlinear Nonhydrostatic Internal Tides Ove...

By: T. Gerkema; R. Maugé

Description: Laboratoire de Physique des Océans, Université de Bretagne Occidentale, 6 avenue Le Gorgeu, 29238 Brest, France. A set of evolution equations is derived for the modal coefficients in a weakly nonlinear nonhydrostatic internal-tide generation problem. The equations allow for the presence of large-amplitude topography, e.g. a continental slope, which is formally assumed to have a length scale much larger than that of the internal tide. However, comparison ...

Akylas, T R., Grimshaw, R. H J., Clarke, S R., and Tabaei, A.: Reflecting tidal wave beams and local generation of solitary waves in the ocean thermocline, J. Fluid Mech., 593, 297–313, 2007.; Bender, C M. and Orszag, S A.: Advanced mathematical methods for scientists and engineers, McGraw-Hill, 1978.; Durran, D R.: Numerical methods for wave equations in geophysical fluid dynamics, Springer, 1999.; Garrett, C. and Gerkema, T.: On the body-force term in internal-tide gen...

Read More
 
1
|
2
|
3
Records: 1 - 20 of 45 - Pages: 



Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.