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1
Yoshiyasu, Yusuke, and Nobutoshi Yamazaki. "Pose Space Surface Manipulation." International Journal of Computer Games Technology 2012 (2012): 1–13. http://dx.doi.org/10.1155/2012/596953.
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Example-based mesh deformation techniques produce natural and realistic shapes by learning the space of deformations from examples. However, skeleton-based methods cannot manipulate a global mesh structure naturally, whereas the mesh-based approaches based on a translational control do not allow the user to edit a local mesh structure intuitively. This paper presents an example-driven mesh editing framework that achieves both global and local pose manipulations. The proposed system is built with a surface deformation method based on a two-step linear optimization technique and achieves direct manipulations of a model surface using translational and rotational controls. With the translational control, the user can create a model in natural poses easily. The rotational control can adjust the local pose intuitively by bending and twisting. We encode example deformations with a rotation-invariant mesh representation which handles large rotations in examples. To incorporate example deformations, we infer a pose from the handle translations/rotations and perform pose space interpolation, thereby avoiding involved nonlinear optimization. With the two-step linear approach combined with the proposed multiresolution deformation method, we can edit models at interactive rates without losing important deformation effects such as muscle bulging.
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Sieger, Daniel, Sergius Gaulik, Jascha Achenbach, Stefan Menzel, and Mario Botsch. "Constrained space deformation techniques for design optimization." Computer-Aided Design 72 (March 2016): 40–51. http://dx.doi.org/10.1016/j.cad.2015.07.004.
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Aschieri, Paolo. "Deformation quantization of principal bundles." International Journal of Geometric Methods in Modern Physics 13, no. 08 (September 2016): 1630010. http://dx.doi.org/10.1142/s0219887816300105.
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We outline how Drinfeld twist deformation techniques can be applied to the deformation quantization of principal bundles into noncommutative principal bundles and, more in general, to the deformation of Hopf–Galois extensions. First, we twist deform the structure group in a quantum group, and this leads to a deformation of the fibers of the principal bundle. Next, we twist deform a subgroup of the group of automorphisms of the principal bundle, and this leads to a noncommutative base space. Considering both deformations, we obtain noncommutative principal bundles with noncommutative fiber and base space as well.
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Gasbarri, Paolo, Giovanni B. Palmerini, Giuliano Coppotelli, and Chiara Toglia. "Validation of attitude/deformation sensing techniques for space flexible manipulators." Acta Astronautica 64, no. 2-3 (January 2009): 212–21. http://dx.doi.org/10.1016/j.actaastro.2008.07.020.
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Robbins, J. W. "Geophysics 1990: Regional deformation and global tectonics from space geodetic techniques." Eos, Transactions American Geophysical Union 72, no. 14 (1991): 162. http://dx.doi.org/10.1029/90eo00125.
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Ilia, I., C. Loupasakis, and P. Tsangaratos. "ASSESSING GROUND SUBSIDENCE PHENOMENA WITH PERSISTENT SCATTERER INTERFEROMETRY DATA IN WESTERN THESSALY, GREECE." Bulletin of the Geological Society of Greece 50, no. 3 (July 27, 2017): 1693. http://dx.doi.org/10.12681/bgsg.11892.
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The main objective of the present study was to investigate ground subsidence in the wider area of Farsala, western Thessaly basin, by means of remote sensing techniques and to identify potential geo environmental mechanisms that contribute to the development of the observed surface fractures affecting the site. In this context, a set of Synthetic Aperture Radar (SAR) images, acquired in 1995-2003 by the European Space Agency (ESA) satellites ERS1 and ERS2 and processed with the Persistent Scatterer Interferometry (PSI) technique by the German Space Agency (DLR) during the Terrafirma project, were evaluated in order to investigate spatial and temporal patterns of deformation. Groundwater table levels of three water boreholes within the research area were processed providing the mean piezometric level drawdown and the mean annual drawdown rate. In addition, a quantitative comparison between the deformation subsidence rate and the thickness of the compressible sediments was also performed. The outcomes of the present study indicated a clear relationship in the subsidence deformation rate and the groundwater fluctuation and also a correlation between the depth of the bedrock and the deformation subsidence rate. Overall, the multitemporal SAR interferometry (DInSAR) data are proved as a valuable and suitable technique for increasing knowledge about the extent and the rate of the deformations in the current study area, proved to be affected with an increasing intensity.
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Li, Runguang, Youkang Wang, Xiaojing Liu, Shilei Li, Qing Tan, Wenjun Liu, Xing Fang, and Yan-Dong Wang. "Micromechanical behaviors related to confined deformation in pure titanium." MATEC Web of Conferences 321 (2020): 12018. http://dx.doi.org/10.1051/matecconf/202032112018.
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Confined deformation, e.g. mechanical twinning, shear banding, and Lüders banding, etc. was extensively observed in metals and alloys with low stacking-fault energies, especially under complex loadings, governing the mechanical properties. It is often accompanied with gradient microstructures to accommodate the stress concentrations. Understanding the micromechanical behaviors of structural materials having confined deformation is important for evaluating the structural stabilities of engineering components. Synchrotron-based techniques provide powerful tools for multiscale microstructural characterization owing to their good resolution in real/reciprocal space, fast data collection/processing and flexible application scenarios. In this paper, the synchrotron-based high-energy X-ray diffraction (HE-XRD) and microdiffraction (μXRD) techniques in combination with traditional characterization methods are used to reveal the deformational gradient structures/stresses under different loading modes in multiscale. The structure/stress gradients induced by laser shot peening treatment and the deformation twins generated during uniaxial tensile loading in pure titanium were systematically studied by HE-XRD and μXRD, in order to elucidate the accommodating role of the deformational structures subjected to various confined scenarios. The new finding regarding the micromechanical behaviors related to confined deformation contributes to the in-depth understanding of related complex deformation behaviors.
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Visentin, Silvia, Chiara Palermo, Martina Camerin, Luciano Daliento, Denisa Muraru, Erich Cosmi, and Luigi P. Badano. "Echocardiographic Techniques of Deformation Imaging in the Evaluation of Maternal Cardiovascular System in Patients with Complicated Pregnancies." BioMed Research International 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/4139635.
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Cardiovascular diseases (CVD) represent the leading cause of maternal mortality and morbidity. Knowledge of CVD in women is constantly evolving and data are emerging that female-specific risk factors as complications of pregnancy are conditions associated with an increased risk for the long-term development of CVD. Echocardiography is a safe and effective imaging technique indicated in symptomatic or asymptomatic pregnant women with congenital heart diseases who require close monitoring of cardiac function. Deformation imaging is an echocardiographic technique used to assess myocardial function by measuring the actual deformation of the myocardium through the cardiac cycle. Speckle-tracking echocardiography (STE) is a two-dimensional (2D) technique which has been found to be more accurate than tissue Doppler to assess both left ventricular (LV) and right ventricular (RV) myocardial function. The use of 2D STE however might present some technical issues due to the tomographic nature of the technique and the motion in the three-dimensional space of the myocardial speckles. This has promoted the use of 3D STE to track the motion of the speckles in the 3D space. This review will focus on the clinical value of the new echocardiographic techniques of deformation imaging used to assess the maternal cardiovascular system in complicated pregnancies.
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Nurdin, A., N. W. Bressloff, A. J. Keane, and C. M. E. Holden. "Shape optimisation using CAD linked free-form deformation." Aeronautical Journal 116, no. 1183 (September 2012): 915–39. http://dx.doi.org/10.1017/s0001924000007351.
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AbstractFree-form deformation (FFD) is a method first introduced within the graphics industry to enable flexible deformation of geometric models. FFD uses an R3 to R3 mapping of a deformable space to the global Cartesian space to produce the geometry deformation. This method has been extensively used within the design optimisation field as a shape parameterisation technique. Typically it has been used to parameterise analysis meshes, where new design geometries are produced by deforming the original mesh. This method allows a concise set of design variables to be used while maintaining a flexible shape representation. However, if a computer aided design (CAD) model of the resulting geometry is required, reverse engineering techniques would need to be utilised to recreate the model from the deformed mesh. This paper extends the use of FFD within an optimisation routine by using FFD to directly parameterise a CAD geometry. Two methods of linking the FFD methods with the CATIA V5 CAD package are presented. Each CAD integration technique is then critiqued with respect to shape optimisation. Finally the set-up and initialisation of a case study is illustrated. The case study chosen is the aerodynamic optimisation of the wing-fuselage junction of a typical passenger aircraft.
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Govil, H., R. S. Chatterjee, K. Malik, P. Diwan, M. K. Tripathi, and S. Guha. "IDENTIFICATION AND MEASUREMENT OF DEFORMATION USING SENTINEL DATA AND PSINSAR TECHNIQUE IN COALMINES OF KORBA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-5 (November 19, 2018): 427–31. http://dx.doi.org/10.5194/isprs-archives-xlii-5-427-2018.
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<p><strong>Abstract.</strong> Natural Resources extraction for production of goods increases the stress on land and on the environment. Coal Mines are the primary source for energy production. This process increases the continuous deformation on land by disturbing equilibrium beneath the surface. Interferometry techniques have a capability to detect the minute deformation with millimetre precision on the ground using microwave SAR data. The study area covers the largest open cast coal mines of Asia. In this study for minute deformation identification, Persistent Scatterer Interferometry Synthetic Aperture Radar (PSInSAR) technique has been used. Research focuses on the application of PSInSAR technique for terrain deformation detection using 17 SAR scene of Korba, Chhattisgarh, India acquired by the Sentinel-1 satellite of European Space Agency. This technique is capable to monitor the minute deformation in the coal mines of Korba, Chhattisgarh, India. The results predicted that the area is deformed with the velocity up to 30 mm/year in the coal mines and surroundings areas. The PSInSAR technique with the Sentinel-1 data provides the proficient tool for deformation monitoring in coal mines of Korba.</p>
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HO TONG MINH, Dinh, Ramon Hanssen, and Fabio Rocca. "Radar Interferometry: 20 Years of Development in Time Series Techniques and Future Perspectives." Remote Sensing 12, no. 9 (April 26, 2020): 1364. http://dx.doi.org/10.3390/rs12091364.
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The research and improvement of methods to be used for deformation measurements from space is a challenge. From the previous 20 years, time series Synthetic Aperture Radar (SAR) interferometry techniques have proved for their ability to provide millimeter-scale deformation measurements over time. This paper aims to provide a review of such techniques developed in the last twenty years. We first recall the background of interferometric SAR (InSAR). We then provide an overview of the InSAR time series methods developed in the literature, describing their principles and advancements. Finally, we highlight challenges and future perspectives of the InSAR in the Big Data era.
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Reilinger, Robert. "Geodetic Evidence for Tectonic Deformation in the Eastern United States." Seismological Research Letters 59, no. 4 (October 1, 1988): 314. http://dx.doi.org/10.1785/gssrl.59.4.314.
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Abstract The historic geodetic data base in the eastern United States dates back over 100 years. Although instrumentation and hence measurement precision has improved since the initial observations, the basic techniques [leveling, triangulation, water level gauging] remained unchanged until the recent introduction of space geodesy [Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Positioning System (GPS)]. Because of this, it has been possible to compare repeated observations to identify apparent changes in relative positions. Such “changes” can reflect observational errors, non-tectonic movements (water level effects, monument instability, loading, etc.) or tectonic/isostatic deformation. A number of possible deformation features in the eastern U. S. have been reported in the literature, including uplift of the southern Appalachian and Adirondack mountains, doming of the Gulf coast inland of the Mississippi delta, subsidence of Chesapeak Bay and along the coast of Maine, horizontal deformation in New York and Connecticut, and possible fault related deformation near Charleston and in the New Madrid area. Unfortunately, it is not dear to what extent any of these features represent tectonic deformations and hence what their significance may be for the earthquake problem. An important recent development in monitoring regional deformation has been the establishment of the eastern U. S. GPS strain network by the National Geodetic Survey. The network consists of roughly 45 sites uniformly distributed east of the Rocky Mountains. The network was established in 1987 and will be reobserved in 1989. Subsequent reobservations will be made at 2 to 5 year intervals depending on analysis of the early measurements. Given the precision of the GPS measurements (few cm in 3-D relative positions), a considerable time period will be required to detect the subtle deformations expected for this intraplate region. Perhaps more immediate information will result from recent progress in recognizing and correcting systematic errors in the historic geodetic data base. This, together with the newly automated historic data base, and improved techniques for integrating and analyzing these extensive observations, provide the necessary basis for effectively evaluating the deformational features listed above. Given the potential importance of these data for understanding tectonic processes (and the huge expense of collecting these measurements over the pst century), such studies should be an integral part of future earthquake studies in the eastern U. S.
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Bonarski, Jan T., Igor V. Alexandrov, Vil D. Sitdikov, Leszek Tarkowski, J. Grzonka, and M. Bieda-Niemiec. "Texture/Stress Characteristics of Microstructure Used in Interpreting Deformation Effects of Ti Subjected to ECAP Process." Solid State Phenomena 160 (February 2010): 103–8. http://dx.doi.org/10.4028/www.scientific.net/ssp.160.103.
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The common feature of the technologies, such as the equal channel angular pressing (ECAP) is the use of a changeable deformation path, which changes the configuration (value and direction) of the acting forces that impose various directions of plastic flow. The changes destabilize a temporary dislocation structure as well as the spatial distribution of the areas with elevated elastic energy cumulated in deformed lattice. The application of that technique results in a potentially large deformation (up to several hundred percent) and plasticity of materials considered to be brittle at ambient temperature. The microstructure effects accompanied with intensive and large deformation are reflected in the space orientation of grains (crystallographic texture) as well as in the configuration of the residual stresses existing in deformed material. The presented results based on experimental data registered by X-ray diffraction and TEM techniques are helpful in interpreting deformation mechanisms operating in the bend-zone of the ECAP tool during processing Ti-ingot by the mentioned method of severe plastic deformation.
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LIZASOAIN, INMACULADA, and CRISTINA MORENO. "FUZZY SIMILARITIES TO COMPARE DEFORMED IMAGES." International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems 19, no. 05 (October 2011): 863–77. http://dx.doi.org/10.1142/s0218488511007271.
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We use the concept of fuzzy similarity to compare the objects of a free image algebra (a set of objects which a group is acting on). In particular, we study those fuzzy similarities that are preserved by the action of the group. Later we consider a deformation mechanism of the image algebra and trackle the problem of comparing deformed images. For that purpose, we characterize those deformation mechanisms that are equivalent to the induced action from a subgroup of the group of deformations. In that case, by using techniques from group representation theory, we extend any fuzzy similarity defined on the image algebra to a fuzzy similarity defined on the whole space of deformed images. Moreover, we prove that the invariance of the similarity with respect to the group action is preserved by this extension.
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Jordan, Thomas H., and J. Bernard Minster. "Beyond Plate Tectonics: Looking at Plate Deformation with Space Geodesy." Symposium - International Astronomical Union 129 (1988): 341–50. http://dx.doi.org/10.1017/s0074180900134941.
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We address the requirements that must be met by space-geodetic systems to place useful, new constraints on horizontal secular motions associated with the geological deformation of the earth's surface. Plate motions with characteristic speeds of about 50 mm/yr give rise to displacements that are easily observed by space geodesy. However, in order to improve the existing plate-motion models, the tangential components of relative velocities on interplate baselines must be resolved to an accuracy of < 3 mm/yr. Because motions considered small from a geodetic point of view have rather dramatic geological effects, especially when taken up as compression or extension of continental crust, detecting plate deformation by space-geodetic methods at a level that is geologically unresolvable places rather stringent requirements on the precision of the measurement systems: the tangential components on intraplate baselines must be observed with an accuracy of < 1 mm/yr. Among the measurements of horizontal secular motions that can be made by space geodesy, those pertaining to the rates within the broad zones of deformation characterizing the active continental plate boundaries are the most difficult to obtain by conventional ground-based geodetic and geological techniques. Measuring the velocities between crustal blocks to ± 5 mm/yr on 100-km to 1000-km length scales can yield geologically significant constraints on the integrated deformation rates across continental plate-boundary zones such as the western United States. However, baseline measurements in geologically complicated zones of deformation are useful only to the extent that the endpoints can be fixed in a local kinematical frame that includes major crustal blocks. For this purpose, the establishment of local geodetic networks around major VLBI and SLR sites in active areas should receive high priority.
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Yeh, T. P., and J. M. Vance. "Applying Virtual Reality Techniques to Sensitivity-Based Structural Shape Design." Journal of Mechanical Design 120, no. 4 (December 1, 1998): 612–19. http://dx.doi.org/10.1115/1.2829323.
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Virtual reality (VR) provides a design space consisting of three-dimensional computer images where participants can interact with these images using natural human motions in real time. In the field of engineering design, prototyping and design verification have provided the initial application areas for VR. The research presented in this paper takes the scenario one step further by incorporating free-form deformation techniques and sensitivity analysis into the virtual world such that the designer can easily implement analysis-based shape design of a structural system where stress considerations are important. NURBS-based free-form deformation (NFFD) methods and direct manipulation techniques are used as the interface between the VR interaction and the finite element model. Sensitivity analysis is used to allow the designer to change the design model and immediately view the effects without performing a re-analysis. An engine connecting rod is analyzed to demonstrate how virtual reality techniques can be applied to structural shape design.
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Richter, B., S. Zerbini, F. Matonti, and D. Simon. "Long-term crustal deformation monitored by gravity and space techniques at Medicina, Italy and Wettzell, Germany." Journal of Geodynamics 38, no. 3-5 (October 2004): 281–92. http://dx.doi.org/10.1016/j.jog.2004.07.013.
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Zecevic, Megan, Thomas S. Eyre, and David W. Eaton. "Static Ground Displacement for an Induced Earthquake Recorded on Broadband Seismometers." Bulletin of the Seismological Society of America 110, no. 5 (August 4, 2020): 2216–24. http://dx.doi.org/10.1785/0120200074.
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ABSTRACT Using geodetic methods, significant static ground deformation has been observed for many large natural earthquakes. Some of the largest earthquakes induced by hydraulic-fracturing operations have been observed in the Western Canada Sedimentary Basin; however, because of the size and depths of these events, the associated static ground deformations have not yet been observed using traditional geodetic techniques. A seismic processing technique, developed for small volcano-seismic events, has the potential to resolve micrometer-scale static displacements using broadband seismic data. In this study, we test this processing method using vertical component broadband recordings of an Mw 4.1 event acquired at four nearby broadband seismometers. Estimated static displacements at the four stations are compared with the theoretical surface displacement field for a dislocation on a finite rectangular source within a homogeneous, elastic half-space. The theoretical displacements have the same polarities as the measured displacements across the seismic network and have similar amplitudes for three of the four stations. However, one station yielded unstable results, which shows that care must be taken when using this method. These results suggest that this processing method has potential for obtaining surface deformation for small to moderate-sized earthquakes using broadband data.
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Zhao, Bao Yun, and Ke Shan Zhu. "Brief Comments on “Unloading Rock Mechanics” and Engineering Applications." Applied Mechanics and Materials 256-259 (December 2012): 211–14. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.211.
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Since rock masses are not a true continuous, homogeneous, isotropic and linear-elastic (CHILE) continuum, the loading and unloading behaviors differ greatly from each other. Professor Ha Qiulin and his co-workers have demonstrated that strength and deformational characteristics, initial rock stresses, scale effects, creep, deformation and fracture patterns are quite different and stress path dependence is particularly emphasized. As engineering unloading of the rock mass is essentially of a dynamic nature by excavation, we will first discuss the excavation process and related stabilization techniques. For the complex stress and deformation conditions around the excavated boundaries, it seems rational to define an excavation disturbed zone (EDZ) as in the last decades. In tunnel excavation, temperature and ventilation effects should be also taken into account. Space-and-time dependence on tunnel behaviors is important. Finally, further research topics are discussed.
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Nefeslioglu, Hakan A., Beste Tavus, Melahat Er, Gamze Ertugrul, Aybuke Ozdemir, Alperen Kaya, and Sultan Kocaman. "Integration of an InSAR and ANN for Sinkhole Susceptibility Mapping: A Case Study from Kirikkale-Delice (Turkey)." ISPRS International Journal of Geo-Information 10, no. 3 (February 27, 2021): 119. http://dx.doi.org/10.3390/ijgi10030119.
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Suitable route determination for linear engineering structures is a fundamental problem in engineering geology. Rapid evaluation of alternative routes is essential, and novel approaches are indispensable. This study aims to integrate various InSAR (Interferometric Synthetic Aperture Radar) techniques for sinkhole susceptibility mapping in the Kirikkale-Delice Region of Turkey, in which sinkhole formations have been observed in evaporitic units and a high-speed train railway route has been planned. Nine months (2019–2020) of ground deformations were determined using data from the European Space Agency’s (ESA) Sentinel-1A/1B satellites. A sinkhole inventory was prepared manually using satellite optical imagery and employed in an ANN (Artificial Neural Network) model with topographic conditioning factors derived from InSAR digital elevation models (DEMs) and morphological lineaments. The results indicate that high deformation areas on the vertical displacement map and sinkhole-prone areas on the sinkhole susceptibility map (SSM) almost coincide. InSAR techniques are useful for long-term deformation monitoring and can be successfully associated in sinkhole susceptibility mapping using an ANN. Continuous monitoring is recommended for existing sinkholes and highly susceptible areas, and SSMs should be updated with new results. Up-to-date SSMs are crucial for the route selection, planning, and construction of important transportation elements, as well as settlement site selection, in such regions.
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Motreanu, V. V. "Minimax Results with Respect to Different Altitudes in the Situation of Linking." Abstract and Applied Analysis 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/781746.
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Consider a continuous function on a metric space. In the presence of linking between a compact pair and a closed set, depending on the different behaviors of the function on the linking sets, we establish minimax results guaranteeing existence of Palais-Smale sequences or providing gradient estimates. Our approach relies on deformation techniques.
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Krakow, Robert, Robbie J. Bennett, Duncan N. Johnstone, Zoja Vukmanovic, Wilberth Solano-Alvarez, Steven J. Lainé, Joshua F. Einsle, Paul A. Midgley, Catherine M. F. Rae, and Ralf Hielscher. "On three-dimensional misorientation spaces." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 473, no. 2206 (October 2017): 20170274. http://dx.doi.org/10.1098/rspa.2017.0274.
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Determining the local orientation of crystals in engineering and geological materials has become routine with the advent of modern crystallographic mapping techniques. These techniques enable many thousands of orientation measurements to be made, directing attention towards how such orientation data are best studied. Here, we provide a guide to the visualization of misorientation data in three-dimensional vector spaces, reduced by crystal symmetry, to reveal crystallographic orientation relationships. Domains for all point group symmetries are presented and an analysis methodology is developed and applied to identify crystallographic relationships, indicated by clusters in the misorientation space, in examples from materials science and geology. This analysis aids the determination of active deformation mechanisms and evaluation of cluster centres and spread enables more accurate description of transformation processes supporting arguments regarding provenance.
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Łach, Łukasz. "Modeling of Microstructure Evolution during Deformation Processes by Cellular Automata—Boundary Conditions and Space Reorganization Aspects." Materials 14, no. 6 (March 12, 2021): 1377. http://dx.doi.org/10.3390/ma14061377.
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Cellular automata (CA) are efficient and effective numerical tools for modeling various phenomena and processes, e.g., microstructure evolution in plastic working processes. In many cases, the analysis of phenomena can be carried out only in a limited space and on representative volume. This limitation determines the geometry of CA space hence boundary conditions are very important issues in modeling. The paper discusses different boundary conditions that can be applied to modeling. Taking into account the transformation of the modeling space, the model should allow the selection of boundary conditions. The modeling of certain phenomena and processes is directly related to changes in the geometry of a representative volume and therefore may require changes or reorganization of the modeled CA space. Four reorganization options are presented: halving, cutting and bonding, doubling, and straightening. A choice of boundary conditions may depend on particular space reorganization as used for the modeling of microstructure evolution. A set of decision rules for selecting space reorganization options taking into account the changes of CA shape and sizes is also presented. The modeling of flat and shape rolling processes utilizing some of the described techniques is shown.
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Wu, Xiaoping, Jürgen Kusche, and Felix W. Landerer. "A new unified approach to determine geocentre motion using space geodetic and GRACE gravity data." Geophysical Journal International 209, no. 3 (March 3, 2017): 1398–402. http://dx.doi.org/10.1093/gji/ggx086.
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Abstract Geocentre motion between the centre-of-mass of the Earth system and the centre-of-figure of the solid Earth surface is a critical signature of degree-1 components of global surface mass transport process that includes sea level rise, ice mass imbalance and continental-scale hydrological change. To complement GRACE data for complete-spectrum mass transport monitoring, geocentre motion needs to be measured accurately. However, current methods of geodetic translational approach and global inversions of various combinations of geodetic deformation, simulated ocean bottom pressure and GRACE data contain substantial biases and systematic errors. Here, we demonstrate a new and more reliable unified approach to geocentre motion determination using a recently formed satellite laser ranging based geocentric displacement time-series of an expanded geodetic network of all four space geodetic techniques and GRACE gravity data. The unified approach exploits both translational and deformational signatures of the displacement data, while the addition of GRACE's near global coverage significantly reduces biases found in the translational approach and spectral aliasing errors in the inversion.
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Farolfi, Gregorio, Aldo Piombino, and Filippo Catani. "Fusion of GNSS and Satellite Radar Interferometry: Determination of 3D Fine-Scale Map of Present-Day Surface Displacements in Italy as Expressions of Geodynamic Processes." Remote Sensing 11, no. 4 (February 15, 2019): 394. http://dx.doi.org/10.3390/rs11040394.
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We present a detailed map of ground movement in Italy derived from the combination of the Global Navigation Satellite System (GNSS) and Satellite Synthetic Aperture Radar (SAR) interferometry. These techniques are two of the most used space geodetic techniques to study Earth surface deformation. The above techniques provide displacements with respect to different components of the ground point position; GNSSs use the geocentric International Terrestrial Reference System 1989 (ITRS89), whereas the satellite SAR interferometry components are identified by the Lines of Sight (LOSs) between a satellite and ground points. Moreover, SAR interferometry is a differential technique, and for that reason, displacements have no absolute reference datum. We performed datum alignment of InSAR products using precise velocity fields derived from GNSS permanent stations. The result is a coherent ground velocity field with detailed boundaries of velocity patterns that provide new information about the complex geodynamics involved on the Italian peninsula and about local movements.
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Ammirati, Lorenzo, Nicola Mondillo, Ricardo Adolfo Rodas, Chester Sellers, and Diego Di Martire. "Monitoring Land Surface Deformation Associated with Gold Artisanal Mining in the Zaruma City (Ecuador)." Remote Sensing 12, no. 13 (July 3, 2020): 2135. http://dx.doi.org/10.3390/rs12132135.
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Underground mining can produce subsidence phenomena, especially if orebodies are surficial or occur in soft rocks. In some countries, illegal mining is a big problem for environmental, social and economic reasons. However, when unauthorized excavation is conducted underground, it is even more dangerous because it can produce unexpected surficial collapses in areas not adequately monitored. For this reason, it is important to find quick and economic techniques able to give information about the spatial and temporal development of uncontrolled underground activities in order to improve the risk management. In this work, the differential interferometric synthetic aperture radar (DInSAR) technique, implemented in the SUBSOFT software, has been used to study terrain deformation related to illegal artisanal mining in Ecuador. The study area is located in Zaruma (southeast of El Oro province), a remarkable site for Ecuadorian cultural heritage where, at the beginning of the 2017, a local school collapsed, due to sinkhole phenomena that occurred around the historical center. The school, named “Inmaculada Fe y Alegria”, was located in an area where mining activity was forbidden. For this study, the surface deformations that occurred in the Zaruma area from 2015 to 2019 were detected by using the Sentinel-1 data derived from the Europe Space Agency of the Copernicus Program. Deformations of the order of five centimeters were revealed both in correspondence of known exploitation tunnels, but also in areas where the presence of tunnels had not been verified. In conclusion, this study allowed to detect land surface movements related to underground mining activity, confirming that the DInSAR technique can be applied for monitoring mining-related subsidence.
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Adak, Malabika, and N. R. Mandal. "Thermomechanical Analysis of Plates Undergoing Line Heating Using Pseudolinear Equivalent Constant Rigidity System." Journal of Ship Production 20, no. 02 (May 1, 2004): 84–89. http://dx.doi.org/10.5957/jsp.2004.20.2.84.
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Line-heating technique involves application of controlled thermal cycles. In developing the technique of line heating, which is nonlinear and involves plastic deformation of the medium at high temperature varying in both time and space, analytical solutions turned out to be inadequate. At the same time conventional numerical techniques proved to be highly time consuming and thereby prohibitively expensive in real life situations. In this investigation, the initial nonlinear problem with modulus varying with temperature was transformed into a pseudolinear equivalent system of constant rigidity that was solved by applying linear analysis. The analysis procedure presented in this work and the results thus obtained hold great promise for analyzing the complicated thermal elastic-plastic problems as encountered in line-heating process.
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Spear, Derek G., Anthony N. Palazotto, and Ryan A. Kemnitz. "Modeling and Simulation Techniques Used in High Strain Rate Projectile Impact." Mathematics 9, no. 3 (January 30, 2021): 274. http://dx.doi.org/10.3390/math9030274.
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A series of computational models and simulations were conducted for determining the dynamic responses of a solid metal projectile impacting a target under a prescribed high strain rate loading scenario in three-dimensional space. The focus of this study was placed on two different modeling techniques within finite element analysis available in the Abaqus software suite. The first analysis technique relied heavily on more traditional Lagrangian analysis methods utilizing a fixed mesh, while still taking advantage of the finite difference integration present under the explicit analysis approach. A symmetry reduced model using the Lagrangian coordinate system was also developed for comparison in physical and computational performance. The second analysis technique relied on a mixed model that still made use of some Lagrangian modeling, but included smoothed particle hydrodynamics techniques as well, which are mesh free. The inclusion of the smoothed particle hydrodynamics was intended to address some of the known issues in Lagrangian analysis under high displacement and deformation. A comparison of the models was first performed against experimental results as a validation of the models, then the models were compared against each other based on closeness to experimentation and computational performance.
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Dane, Thomas, Emanuela Di Cola, Lionel Lardiere, Cedric Montero, Michael Sztucki, Britta Weinhausen, and Manfred Burghammer. "Exploring fibrous materials with micro/nanobeam scanning diffraction techniques." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1071. http://dx.doi.org/10.1107/s2053273314089281.
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Fibrous materials play an important role in many fields of research spanning from industrial applications to life sciences. They are typically organized in hierarchical arrangements of structural features on multiple length scales. Employing focused monochromatic x-rays combined with scanning diffraction, such samples can be studied obtaining rich information in reciprocal space (molecular to mesoscale level) and direct space simultaneously [1][2]. The resolution of the latter is mainly limited by the focal spot size ranging from a few microns down to 100 nm and less. The arrival of fast, sensitive pixel array detectors during the past years and the availability of high performance focusing optics enable in-situ studies on weakly scattering specimen like single polymer fibers and bio-composite materials (e.g. wood, bone tissue, ...) controlling environmental parameters such as humidity, temperature, and mechanical deformation. In this contribution we will present in a first part the state of the art of instrumentation for such experiments at the ESRF Microfocus Beamline, illustrated with recent examples. The figure below shows an example of a single fiber diffraction pattern of a high performance polymer (KEVLAR®) obtained from a 20 ms exposure with a 1.5 micron beam (Frelon CCD detector, 2k x 2k pixels, 13 keV photon energy). In the second part, future opportunities for scanning diffraction experiments emerging from potential upgrades of 3rd generation synchrotron radiation sources, as currently explored at the ESRF and elsewhere, will be discussed.
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Demo, Nicola, Marco Tezzele, Andrea Mola, and Gianluigi Rozza. "Hull Shape Design Optimization with Parameter Space and Model Reductions, and Self-Learning Mesh Morphing." Journal of Marine Science and Engineering 9, no. 2 (February 11, 2021): 185. http://dx.doi.org/10.3390/jmse9020185.
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In the field of parametric partial differential equations, shape optimization represents a challenging problem due to the required computational resources. In this contribution, a data-driven framework involving multiple reduction techniques is proposed to reduce such computational burden. Proper orthogonal decomposition (POD) and active subspace genetic algorithm (ASGA) are applied for a dimensional reduction of the original (high fidelity) model and for an efficient genetic optimization based on active subspace property. The parameterization of the shape is applied directly to the computational mesh, propagating the generic deformation map applied to the surface (of the object to optimize) to the mesh nodes using a radial basis function (RBF) interpolation. Thus, topology and quality of the original mesh are preserved, enabling application of POD-based reduced order modeling techniques, and avoiding the necessity of additional meshing steps. Model order reduction is performed coupling POD and Gaussian process regression (GPR) in a data-driven fashion. The framework is validated on a benchmark ship.
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Mori, Susumu. "Two and Three-dimensional Analyses of Brain White Matter Architecture Using Diffusion Imaging." CNS Spectrums 7, no. 7 (July 2002): 529–34. http://dx.doi.org/10.1017/s1092852900018083.
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ABSTRACTThe raw diffusion tensor imaging data obtained after tensor calculations contain six tensor elements in each pixel. This unique data structure poses difficulties in visualizing and analyzing diffusion tensor imaging data. One of the most commonly used visualization techniques is the use of color-coded maps. This presents fiber orientation information as a mixture of three principal colors. These maps can reveal white matter substructures that may not be visible in conventional magnetic resonance imaging. By extending the fiber-orientation information into three-dimensional space, three-dimensional trajectories of white matter tracts can then be estimated. Once locations and trajectories of tracts of interest are identified, this technique allows for the utilization of tract-specific magnetic resonance analyses and/or macroscopic characterization of white matter anatomy. As an example, anatomical deformation of the white matter resultant of brain tumor is demonstrated. The potentials and limitations of the three-dimensional tract reconstruction techniques are also highlighted.
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Sansosti, E., F. Casu, M. Manzo, and R. Lanari. "Space-borne radar interferometry techniques for the generation of deformation time series: An advanced tool for Earth's surface displacement analysis." Geophysical Research Letters 37, no. 20 (October 2010): n/a. http://dx.doi.org/10.1029/2010gl044379.
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Río-López, Natalia A., Patricia Lázpita, Daniel Salazar, Viktor I. Petrenko, Fernando Plazaola, Volodymyr Chernenko, and Jose M. Porro. "Neutron Scattering as a Powerful Tool to Investigate Magnetic Shape Memory Alloys: A Review." Metals 11, no. 5 (May 18, 2021): 829. http://dx.doi.org/10.3390/met11050829.
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Magnetic shape memory alloys (MSMAs) are an interesting class of smart materials characterized by undergoing macroscopic deformations upon the application of a pertinent stimulus: temperature, stress and/or external magnetic fields. Since the deformation is rapid and contactless, these materials are being extensively investigated for a plethora of applications, such as sensors and actuators for the medical, automotive and space industries, energy harvesting and damping devices, among others. These materials also exhibit a giant magnetocaloric effect, whereby they are very promising for magnetic refrigeration. The applications in which they can be used are extremely dependent on the material properties, which are, in turn, greatly conditioned by the structure, atomic ordering and magnetism of a material. Particularly, exploring the material structure is essential in order to push forward the current application limitations of the MSMAs. Among the wide range of available characterization tools, neutron scattering techniques stand out in acquiring advanced knowledge about the structure and magnetism of these alloys. Throughout this manuscript, a comprehensive review about the characterization of MSMAs using neutron techniques is presented. Several elastic neutron scattering techniques will be explained and exemplified, covering neutron imaging techniques—such as radiography, tomography and texture diffractometry; diffraction techniques—magnetic (polarized neutron) diffraction, powder neutron diffraction and single crystal neutron diffraction, reflectometry and small angle neutron scattering. This will be complemented with a few examples where inelastic neutron scattering has been employed to obtain information about the phonon dispersion in MSMAs.
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Mohamadi, Bahaa, Timo Balz, and 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 (October 12, 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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Camacho and Fernández. "Modeling 3D Free-geometry Volumetric Sources Associated to Geological and Anthropogenic Hazards from Space and Terrestrial Geodetic Data." Remote Sensing 11, no. 17 (August 29, 2019): 2042. http://dx.doi.org/10.3390/rs11172042.
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Recent decades have shown an explosion in the quantity and quality of geodetic data, mainly space-based geodetic data, that are being applied to geological and anthropogenic hazards. This has produced the need for new approaches for analyzing, modeling and interpreting these geodetic data. Typically, modeling of deformation and gravity changes follows an inverse approach using analytical or numerical solutions, where normally regular geometries (point sources, disks, prolate or oblate spheroids, etc.) are assumed at the initial stages and the inversion is carried out in a linear context. Here we review an original methodology for the simultaneous, nonlinear inversion of gravity changes and/or surface deformation (measured with different techniques) to determine 3D (three-dimensional) bodies, without any a priori assumption about their geometries, embedded into an elastic or poroelastic medium. Such a fully nonlinear inversion has led to interesting results in volcanic environments and in the study of water tables variation due to its exploitation. This methodology can be used to invert geodetic remote sensing data or terrestrial data alone, or in combination.
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COLOMO, F., G. MUSSARDO, and A. KOUBEK. "ON THE S MATRIX OF THE SUBLEADING MAGNETIC DEFORMATION OF THE TRICRITICAL ISING MODEL IN TWO DIMENSIONS." International Journal of Modern Physics A 07, no. 21 (August 20, 1992): 5281–305. http://dx.doi.org/10.1142/s0217751x92002416.
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We compute the S matrix of the tricritical Ising model perturbed by the subleading magnetic operator using Smirnov’s RSOS reduction of the Izergin-Korepin model. The massive model contains kink excitations which interpolate between two degenerate asymmetric vacua. As a consequence of the different structure of the two vacua, the crossing symmetry is implemented in a nontrivial way. We use finite-size techniques to compare our results with the numerical data obtained by the truncated conformal space approach and find good agreement.
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Godet, Stéphane, You Liang He, John J. Jonas, and Pascal J. Jacques. "Multiscale Characterisation of the Transformation Texture in a High Performance Steel." Materials Science Forum 495-497 (September 2005): 381–86. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.381.
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The orientation relationships operating during the austenite (FCC) to BCC phase transformation were investigated in a high performance steel using X-ray and electron diffraction techniques and employing several length scales. These steels contain some retained austenite that permits the direct comparison of the textures of the parent (austenite) and product (ferrite, bainite, martensite) phases. X-ray diffraction allowed the global texture of the rolled parent austenite phase to be determined as well as that of its transformation product. EBSD techniques permitted study of the orientation relationships on a local scale. The observed correspondence relations are expressed in Rodrigues-Frank space. The exact Kurdjumov-Sachs relation was never found. The local spread of orientation in the parent austenite (due to deformation) is seen to be inherited by the bainite. This is attributed to the displacive mode of transformation to bainite. The influence of prior deformation of the austenite on the occurrence of variant selection was also studied. It appears that a critical strain is necessary to produce a significant amount of variant selection.
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Sundararaman, KA, KP Padmanaban, M. Sabareeswaran, and S. Guharaja. "An integrated finite element method, response surface methodology, and evolutionary techniques for modeling and optimization of machining fixture layout for 3D hollow workpiece geometry." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 23 (August 31, 2016): 4344–59. http://dx.doi.org/10.1177/0954406216668208.
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Machining fixtures play inevitable role in manufacturing to ensure the machining accuracy and workpiece quality. The layout of fixture elements, clamping forces, and machining forces significantly affect the workpiece elastic deformation during machining. The clamping and machining forces are necessary to immobilize and machine the workpiece, respectively. Finding the appropriate layout of fixture elements is the other possible way to reduce the workpiece deformation, which in turn improves the machining accuracy. The finite element method interfaced with evolutionary techniques is normally used for fixture layout optimization. In the finite element method, the workpiece is discretized into a number of small elements and fixture elements are placed only on the nodes. Hence, evolutionary techniques are capable of searching the optimal fixture layout from those discrete nodal points than from the entire area on the locating and clamping face. To overcome these limitations, in this research paper, response surface methodology is employed to establish a quadratic model between the position of fixture elements and maximum workpiece deformation. This enables the optimization techniques to search for the optimal solution in the continuous domain of the solution space. Then, the real-coded genetic algorithm based discrete optimization, continuous optimization based on binary-coded genetic algorithm and particle swarm optimization are employed to optimize the developed quadratic model and their performances are compared. The result clearly shows that the integration of finite element method, response surface methodology with particle swarm optimization is better than the integration with genetic algorithm to optimize the machining fixture layout and also reduces the computational complexity and time to a greater extent.
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Gojcic, Zan, Caifa Zhou, and Andreas Wieser. "F2S3: Robustified determination of 3D displacement vector fields using deep learning." Journal of Applied Geodesy 14, no. 2 (April 26, 2020): 177–89. http://dx.doi.org/10.1515/jag-2019-0044.
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AbstractAreal deformation monitoring based on point clouds can be a very valuable alternative to the established point-based monitoring techniques, especially for deformation monitoring of natural scenes. However, established deformation analysis approaches for point clouds do not necessarily expose the true 3D changes, because the correspondence between points is typically established naïvely. Recently, approaches to establish the correspondences in the feature space by using local feature descriptors that analyze the geometric peculiarities in the neighborhood of the interest points were proposed. However, the resulting correspondences are noisy and contain a large number of outliers. This impairs the direct applicability of these approaches for deformation monitoring. In this work, we propose Feature to Feature Supervoxel-based Spatial Smoothing (F2S3), a new deformation analysis method for point cloud data. In F2S3 we extend the recently proposed feature-based algorithms with a neural network based outlier detection, capable of classifying the putative pointwise correspondences into inliers and outliers based on the local context extracted from the supervoxels. We demonstrate the proposed method on two data sets, including a real case data set of a landslide located in the Swiss Alps. We show that while the traditional approaches, in this case, greatly underestimate the magnitude of the displacements, our method can correctly estimate the true 3D displacement vectors.
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Toda, Hiroyuki, Kentaro Uesugi, Yoshio Suzuki, and Masakazu Kobayashi. "3D/4D Strain Mapping Using In Situ X-Ray Microtomography." Applied Mechanics and Materials 70 (August 2011): 249–54. http://dx.doi.org/10.4028/www.scientific.net/amm.70.249.
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X-ray microtomography (XMT) has been utilized for the in-situ observation of various structural materials under external disturbance such as loading. In-situ XMT provides a unique possibility to access the three-dimensional (3D) character of internal microstructure and its time evolution behaviours non-destructively, thereby enabling advanced techniques for measuring local strain distribution. Local strain mapping is readily enabled by processing such high-resolution tomographic images either by the particle tracking technique or the digital image correlation technique. Procedures for tracking microstructural features which have been developed by the authors, have been applied to analyse localised deformation and damage evolution in a material. Typically several tens of thousands of microstructural features, such as particles and pores, are tracked in a tomographic specimen (0.2 - 0.3 mm3in volume). When a sufficient number of microstructural features is dispersed in 3D space, the Delaunay tessellation algorithm is used to obtain local strain distribution. With these techniques, 3D strain fields can be measured with reasonable accuracy. Even local crack driving forces, such as local variations in the stress intensity factor, crack tip opening displacement and J integral along a crack front line, can be measured from discrete crack tip displacement fields.
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Xiong, Shangmin, Seung-Yub Lee, and Ismail Cevdet Noyan. "Average and local strain fields in nanocrystals." Journal of Applied Crystallography 52, no. 2 (February 26, 2019): 262–73. http://dx.doi.org/10.1107/s1600576719000372.
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This article presents a rigorous and self-consistent comparison of lattice distortion and deformation fields existing in energy-optimized pseudo-spherical gold nanoparticles obtained from real-space and powder diffraction strain analysis techniques. The changes in atomic positions resulting from energy optimization (relaxation) of ideally perfect gold nanoparticles were obtained using molecular dynamics modeling. The relaxed atomic coordinates were then used to compute the displacement, rotation and strain components in all unit cells within the energy-optimized (relaxed) particles. It was seen that all of these terms were distributed heterogeneously along the radial and tangential directions within the nanospheroids. The heterogeneity was largest in the first few atomic shells adjacent to the nanoparticle surface, where the continuity of crystal lattice vectors originating from the interior layers was broken because of local lattice rotations. These layers also exhibited maximum shear and normal strains. These (real-space) strain values were then compared with the average lattice strains obtained by refining the computed diffraction patterns of such particles. The results show that (i) relying solely on full-pattern refinement techniques for lattice strain analysis might lead to erroneous conclusions about the dimensionality and symmetry of deformation within relaxed nanoparticles; (ii) the lattice strains within such relaxed particles should be considered `eigenstrains' (`inherent strains') as defined by Mura [Micromechanics of Defects in Solids, (1991), 2nd ed., Springer]; and (iii) the stress/strain state within relaxed nanoparticles cannot be analyzed rigorously using the constitutive equations of linear elasticity.
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Raspini, F., C. Loupasakis, D. Rozos, and S. Moretti. "Basin and local scale detection of ground subsidence through persistent scatterer interferometry: The Anthemountas Basin (Northern Greece) case study." Bulletin of the Geological Society of Greece 47, no. 3 (December 21, 2016): 1510. http://dx.doi.org/10.12681/bgsg.10989.
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In the framework of the Terrafirma Extension project, a study has been established for ground motion detection and mapping in the Anthemountas basin (Central Macedonia). Terrafirma promotes the exploitation of Persistent Scatterer Interferometry (PSI) techniques, a remote sensing technology based on multi-temporal satellite Synthetic Aperture Radar (SAR) imagery. The potential of SAR interferometry has been exploited through the innovative Wide Area Mapping approach, recently implemented by the German Space Agency (DLR) and aimed at measuring land deformation over large areas. Interferometric results from 1995-2001 by ERS1/2 satellites has been analyzed at a basin scale to investigate spatial patterns of land motion in the wider Anthemountas plain, where subsidence phenomena related to intense groundwater extraction is clearly manifested. The WAP results turned out to be a valuable tool for the characterization at local scale of the land subsidence in the runaways area of the Macedonia airport and in the village of Perea, affected in 2005-2006 by a series of tensile ground ruptures due to excessive groundwater withdrawal. Besides the study of the phenomenon, this work confirmed the suitability of PSI techniques to detect and measure surface displacements with millimetre accuracy and also to reconstruct the deformations history of the investigated areas through displacement time series analysis.
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Bazanowski, Maciej, Anna Szostak-Chrzanowski, and Adam Chrzanowski. "Determination of GPS Session Duration in Ground Deformation Surveys in Mining Areas." Sustainability 11, no. 21 (November 3, 2019): 6127. http://dx.doi.org/10.3390/su11216127.
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Extraction of underground minerals causes subsidence of the ground surface due to gravitational forces. The subsidence rate depends on the type of extracted ore, as well as its shape, thickness, and depth. Additionally, the embedding and overburden rock properties influence the time needed for the deformations to reach the surface. Using the results of geodetic deformation monitoring, which supply the information on pattern and magnitude of surface deformation, the performance of the mine may be evaluated. The monitoring can supply information on the actual rock mass behaviour during the operation and in many cases during the years after the mining operations have ceased. Geodetic methods of deformation monitoring supply information on the absolute and relative displacements (changes in position in a selected coordinate system) from which displacement and strain fields for the monitored object may be derived. Thus, geodetic measurements provide global information on absolute and relative displacements over large areas, either at discrete points or continuous in the space domain. The geodetic methods are affected by errors caused by atmospheric refraction and delay of electromagnetic signal. Since geodetic measurements allow for redundancy and statistical evaluation of the quality of the data, they generally provide reliable results. Usually, the designed accuracy of deformation measurements should allow for the detection of at least one third of the expected maximum deformations over the desired time span at the 95% probability level. In ground subsidence studies in mining areas, 10 mm accuracy at 95% level in both vertical and horizontal displacements is typically required. In the case of salt mines, the process of ground subsidence in viscous rock is slow; therefore, subsidence monitoring surveys may be performed once a year. In subsidence determination, two techniques are commonly used: leveling and satellite positioning. The satellite positioning technique is used to determine the 3D (horizontal coordinates and height) or 2D position of monitored points (only horizontal coordinates). When comparing the heights determined from satellite and leveling surveys, it has to be noted that the leveling heights are referred with respect to the geoid (orthometric heights), while heights determined from satellite surveys are referred with respect to the ellipsoid (ellipsoidal height). In the case of satellite surveys, the accuracy of horizontal position is typically 2–3 times better than vertical. The analysis of the optimal session duration lead to the conclusion that in order to achieve the sub-cm accuracy of horizontal coordinates at 95% confidence level, the satellite positioning session length using Global Positioning System (GPS) should be at least three hours long. In order to achieve the sub-cm accuracy of height coordinate at 95% confidence level in a single observation session, the GPS session length should be at least twelve hours long.
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Lotfy, Kh, and Wafaa Hassan. "Effect of Rotation for Two-Temperature Generalized Thermoelasticity of Two-Dimensional under Thermal Shock Problem." Mathematical Problems in Engineering 2013 (2013): 1–13. http://dx.doi.org/10.1155/2013/297274.
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The theory of two-temperature generalized thermoelasticity based on the theory of Youssef is used to solve boundary value problems of two-dimensional half-space. The governing equations are solved using normal mode method under the purview of the Lord-Şhulman (LS) and the classical dynamical coupled theory (CD). The general solution obtained is applied to a specific problem of a half-space subjected to one type of heating, the thermal shock type. We study the influence of rotation on the total deformation of thermoelastic half-space and the interaction with each other under the influence of two temperature theory. The material is homogeneous isotropic elastic half-space. The methodology applied here is use of the normal mode analysis techniques that are used to solve the resulting nondimensional coupled field equations for the two theories. Numerical results for the displacement components, force stresses, and temperature distribution are presented graphically and discussed. The conductive temperature, the dynamical temperature, the stress, and the strain distributions are shown graphically with some comparisons.
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Payàs, Blanca, Ryan Morris, Alain Arnaud, David Albiol, and Javier Duro. "Surface monitoring using radar satellite images to measure ground deformation: applied for coal seam gas production areas to comply with regulatory requirements." APPEA Journal 52, no. 2 (2012): 658. http://dx.doi.org/10.1071/aj11072.
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This extended abstract introduces radar satellite reservoir monitoring technology (InSAR) and its main applications for monitoring CSG production areas and its surroundings. InSAR technology detects ground motion with millimetric precision: measurements are taken remotely from space. It is a highly efficient tool for ground-motion measurement, even in large and remote areas, where land-based measurement techniques are inconvenient and costly. Altamira Information has developed an advanced differential interferometric chain (Stable Point Network SPN) that can process radar images, achieving millimetric measurements. Ground-motion monitoring with radar images is an efficient technology to comply with regulatory requirements, arising from CSG activities: regulatory requirements specify the obligation for CSG operators to monitor subsidence starting with a baseline then continue with ongoing monitoring to quantify deformation at the land surface within the proponent’s tenures. InSAR is the only technology able to measure ground deformation in the past since archive radar images are available. These measurements in the past allow establishing baselines to determine vulnerable zones affected by subsidence (before CSG production) or subsidence induced by CSG or other activities. Monitoring requirements for the present and future can be covered with high-resolution satellites—which can be programmed—with precise measurement results (up 1 mm). Case studies are presented from historical data processed from the Surat and southern Bowen Basin CSG developments; these cases include the investigation of both CSG and non-CSG induced surface deformations.
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Ortega, Sebastián, Jochen Wendel, José Santana, Syed Murshed, Isaac Boates, Agustín Trujillo, Alexandru Nichersu, and José Suárez. "Making the Invisible Visible—Strategies for Visualizing Underground Infrastructures in Immersive Environments." ISPRS International Journal of Geo-Information 8, no. 3 (March 20, 2019): 152. http://dx.doi.org/10.3390/ijgi8030152.
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Visualization of underground infrastructure in an interactive 3D immersive environment is extremely important for efficient management of city’s infrastructure. This paper describes different geometric modelling approaches to illustrate appropriate visualization of such data. A multimodal prototype has been developed by exploiting different algorithms to render these invisible underground objects as part of an urban model. This prototype has been integrated in an immersive geographic information system (GIS), named MultiVis, for handheld iOS and Android devices. As a part of the study, three distinct strategies have been tested; the first is based on the use of transparencies to convey a sense of depth, the second relies on an image-space superposition of “ditches” on top of the rendered frame and the third is a world-space deformation of the elevation model that exposes the underground elements. Furthermore, a comparative user experience analysis of different techniques aimed to the geometrically accurate visualisation of utility networks and other underground facilities are performed and evaluated. It includes a set of user evaluations for different parameters of these techniques, which gives us an insight on how the proposed methods affect the experience and usability for technical and non-technical users.
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Qu, Feifei, Zhong Lu, Jin-Woo Kim, and Weiyu Zheng. "Identify and Monitor Growth Faulting Using InSAR over Northern Greater Houston, Texas, USA." Remote Sensing 11, no. 12 (June 25, 2019): 1498. http://dx.doi.org/10.3390/rs11121498.
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Growth faults are widely distributed in the Greater Houston (GH) region of Texas, USA, and the existence of faulting could interrupt groundwater flow and aggravate local deformation. Faulting-induced property damages have become more pronounced over the last few years, necessitating further investigation of these faults. Interferometric synthetic aperture radar (InSAR) has been proved to be an effective way for mapping deformations along and/or across fault traces. However, extracting short-wavelength small-amplitude creep signal (about 10–20 mm/yr) from long time span interferograms is extremely difficult, especially in agricultural or vegetated areas. This study aims to position, map and monitor the rate, extent, and temporal evolution of faulting over GH at the highest spatial density using Multi-temporal InSAR (MTI) technique. The MTI method, which maximizes usable signal and correlation, has the ability to identify and monitor faulting and provide accurate and detailed depiction of active faults. Two neighboring L-band Advanced Land Observing (ALOS) tracks (2007–2011) are utilized in this research. Numerous areas of sharp phase discontinuities have been discerned from MTI-derived velocity map. InSAR measurements allow us to position both previously known faults traces as well as nucleation of new fractures not previously revealed by other ground/space techniques. Faulting damages and surface scarps were evident at most InSAR-mapped fault locations through our site investigations. The newly discovered fault activation appears to be related to excessive groundwater exploitation from the Jasper aquifer in Montgomery County. The continuous mining of groundwater from the Jasper aquifer formed new water-level decline cones over Montgomery County, corroborating the intensity of new fractures. Finally, we elaborate the localized fault activities and evaluate the characteristics of faulting (locking depth and slip rate) through modeling MTI-derived deformation maps. The SW–NE-oriented faults pertain to normal faulting with an average slip rate of 7–13 mm/yr at a shallow locking depth of less than 4 km. Identifying and characterizing active faults through MTI and deformation modeling can provide insights into faulting, its causal mechanism and potential damages to infrastructure over the GH.
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Schneider, P. J., and U. Soergel. "SEGMENTATION OF BUILDINGS BASED ON HIGH RESOLUTION PERSISTENT SCATTERER POINT CLOUDS." ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences V-3-2021 (June 17, 2021): 65–71. http://dx.doi.org/10.5194/isprs-annals-v-3-2021-65-2021.
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Abstract. Integrating differential synthetic aperture radar measurements into building information modeling systems requires a mapping of these measurement points onto structural parts of the building. We use a reverse geocoding approach to project building footprints into slant-range geometry, which helps to accurately assign PS points to single building identities. By treating the deformation time series as points in a high dimensional feature space, we can use dimensional reduction and clustering techniques to extract clusters of points that show a similar movement behavior. We visualize these clusters by mapping them onto ground truth, using laser scanning point clouds. Our approach segments buildings into plausible parts.
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Gueninchault, N., H. Proudhon, and W. Ludwig. "Nanox: a miniature mechanical stress rig designed for near-field X-ray diffraction imaging techniques." Journal of Synchrotron Radiation 23, no. 6 (October 18, 2016): 1474–83. http://dx.doi.org/10.1107/s1600577516013850.
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Multi-modal characterization of polycrystalline materials by combined use of three-dimensional (3D) X-ray diffraction and imaging techniques may be considered as the 3D equivalent of surface studies in the electron microscope combining diffraction and other imaging modalities. Since acquisition times at synchrotron sources are nowadays compatible with four-dimensional (time lapse) studies, suitable mechanical testing devices are needed which enable switching between these different imaging modalities over the course of a mechanical test. Here a specifically designed tensile device, fulfilling severe space constraints and permitting to switch between X-ray (holo)tomography, diffraction contrast tomography and topotomography, is presented. As a proof of concept the 3D characterization of an Al–Li alloy multicrystal by means of diffraction contrast tomography is presented, followed by repeated topotomography characterization of one selected grain at increasing levels of deformation. Signatures of slip bands and sudden lattice rotations inside the grain have been shown by means ofin situtopography carried out during the load ramps, and diffraction spot peak broadening has been monitored throughout the experiment.
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Viganò, Nicola, Wolfgang Ludwig, and Kees Joost Batenburg. "Reconstruction of local orientation in grains using a discrete representation of orientation space." Journal of Applied Crystallography 47, no. 6 (October 17, 2014): 1826–40. http://dx.doi.org/10.1107/s1600576714020147.
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This work presents a mathematical framework for reconstruction of local orientations in grains based on near-field diffraction data acquired in X-ray diffraction contrast tomography or other variants of the monochromatic beam three-dimensional X-ray diffraction methodology. The problem of orientation reconstruction is formulated in terms of an optimization over a six-dimensional space {\bb X}^6 = {\bb R}^3 \otimes {\bb O}^{3}, constructed from the outer product of real and orientation space, and a strongly convergent first-order algorithm that makes use of modern l_1-minimization techniques is provided, to cope with the increasing number of unknowns introduced by the six-dimensional formulation of the reconstruction problem. The performance of the new reconstruction algorithm is then assessed on synthetic data, for varying degrees of deformation, both in a restricted line-beam illumination and in the more challenging full-beam illumination. Finally, the algorithm's behavior when dealing with different kinds of noise is shown. The proposed framework, along the reconstruction algorithm, looks promising for application to real experimental data from materials exhibiting intra-granular orientation spread of up to a few degrees.