Seismicity and regional tectonics of the Estremadura, Southwestern Portugal

The RESTE Project was an integrated geophysical-geological study of the Estremadura, southwestern Portugal. The core of the programme consisted of the acquisition and analysis of microearthquake data. This was complemented by an investigation of the structural evolution of the sedimentary basins of the Estremadura. The geological evolution of the Lusitanian Basin was strongly marked by the reactivation of Palaeozoic basement faults, in response to a sequence of tectonic events: opening of the Central Atlantic, opening of the North Atlantic and Alpine convergence between Africa and Eurasia. The current tectonics are regarded as a subdued continuation of the Miocene deformation (Betic Orogeny), and the "tectonic memory" revealed by the Lusitanian and Lower Tagus Basins is explored to characterize the current tectonic processes. Strike-slip tectonics are identified as a dominant feature of several stages of the evolution of the basins, with particular relevance during the Miocene. The technique of "backstripping" is applied to well data, to constrain the history of vertical movement in the basins. This analysis highlighted the pre mature truncation, in the Late Jurassic, of a normal passive-margin evolution. Tectonic unstability caused the structural inversion of areas within the basins, and seems to have inhibited the predictable thermal subsidence. The rifting process, initially taking place at the Lusitanian Basin, jumped westwards in the Late Jurassic. Crustal underplating and the activity of transfer faults are in-voked as possible explanations for the subsequent deformation of the aborted rift. An upper-plate margin configuration is in good agreement with several observations. The tendency for structural inversion continued throughout theCretaceous, and with the onset of the Alpine convergence in the Turonian the control of the tectonic activity seems to have switched from the Atlantic to the Mediterranean. This reinforced the tectonic unstability, marked by magmatic activity and by a regional upwarp that was to last until the Eocene. Of particular interest was the behaviour, during the Late Cretaceous, of the Setúbal Peninsula sub-basin, which seems to have tilted towards the NW as a block, with a hinge line along the present Lower Tagus Valley. When sedimentation was resumed in the Eocene, a pattern of differential vertical movement was established, with some areas continuing to undergo inversion while nearby areas subsided. This pattern characterized the Cainozoic evolution of the basins, and probably still applies to the neotectonic deformation. The activity of strike-slip basement faults, reactivated under the compressive regime caused by the Afro-Eurasian conver-gence, is proposed as the best explanation for the Miocene deformation, with particular relevance for the Lower Tagus Valley. The RESTE Microearthquake Survey is described, and the data acquired with the RESTE network are analysed. The local earthquakes are accurately located, and focal mechanism solutions are obtained for some of them. This information is used to discuss a neotectonic model for the Lower Tagus Valley. In view of their small magnitudes (l.1< M(_L) < 3.8), the focal mechanisms of these events cannot be interpreted directly in terms of the current tectonics. Such small events are usually local readjustments to previous episodes of deformation. However, such features as the along-strike reversal of the polarity of vertical motion or the coexistence at the same region of different types of source mechanism are diagnostic of strike-slip deformation. This model was supported by the occurrence of a macroearthquake (M(_D)=3.8) with an interpreted source mechanism of sinistral strike-slip. The alignment of four hypocentres along the direction of the Lower Tagus Valley, with a compatible orientation of the interpreted nodal planes, supports the existence of a crustal fracture associated with the Valley. The hypocentral depths of the recorded events reach 20 km, showing that the basement faults responsible for the seismicity affect at least the entire upper crust. Since the limited existing data suggest a high level of heat flow in the Lusitanian Basin, the depths reached by the microearthquakes may indicate an abnormally thick seismogenic layer. An investigation of the broad velocity structure of the lithosphere underneath the RESTE Network using the technique of teleseismic tomographic inversion suggested a correlation between Moho undulations and the inversion of areas of the Lusitanian Basin, and this may indicate that the controlling faults cut the entire crust. In order to provide a rationale for the intraplate seismicity of western Portugal, the neotectonics of Iberia are discussed, and a new kinematic model, centred on the idea of continental extrusion, is proposed. According to the model, a continental block formed by Iberia and northern Morocco is being pushed west wards by the convergence between Africa and Eurasia. The resistance offered by the oceanic parts of the plates varies across the East Azores Transform, leading to dextral shear in the Betic Range. The regional stress field induced by the continental convergence can explain the reactivation, in a simple-shear regime, of basement faults of Hercynian orientation, in particular that proposed for the Lower Tagus Valley

Journal of Telecommunications and Information Technology, 2009, nr 4

kwartalni

Large-Scale Linear Programming

During the week of June 2-6, 1980, the System and Decision Sciences Area of the International Institute for Applied Systems Analysis organized a workshop on large-scale linear programming in collaboration with the Systems Optimization Laboratory (SOL) of Stanford University, and co-sponsored by the Mathematical Programming Society (MPS). The participants in the meeting were invited from amongst those who actively contribute to research in large-scale linear programming methodology (including development of algorithms and software). The first volume of the Proceedings contains five chapters. The first is an historical review by George B. Dantzig of his own and related research in time-staged linear programming problems. Chapter 2 contains five papers which address various techniques for exploiting sparsity and degeneracy in the now standard LU decomposition of the basis used with the simplex algorithm for standard (unstructured) problems. The six papers of Chapter 3 concern aspects of variants of the simplex method which take into account through basis factorization the specific block-angular structure of constraint matrices generated by dynamic and/or stochastic linear programs. In Chapter 4, five papers address extensions of the original Dantzig-Wolfe procedure for utilizing the structure of planning problems by decomposing the original LP into LP subproblems coordinated by a relatively simple LP master problem of a certain type. Chapter 5 contains four papers which constitute a mini-symposium on the now famous Shor-Khachian ellipsoidal method applied to both real and integer linear programs. The first chapter of Volume 2 contains three papers on non-simplex methods for linear programming. The remaining chapters of Volume 2 concern topics of present interest in the field. A bibliography a large-scale linear programming research completes Volume 2

General Catalog 1986-1988

General Catalog of 1986-1988 Contains course descriptions, University college calendar, and college administration.https://digitalcommons.usu.edu/universitycatalogs/1141/thumbnail.jp

Manipulador aéreo con brazos antropomórficos de articulaciones flexibles

[Resumen] Este artículo presenta el primer robot manipulador aéreo con dos brazos antropomórficos diseñado para aplicarse en tareas de inspección y mantenimiento en entornos industriales de difícil acceso para operarios humanos. El robot consiste en una plataforma aérea multirrotor equipada con dos brazos antropomórficos ultraligeros, así como el sistema de control integrado de la plataforma y los brazos. Una de las principales características del manipulador es la flexibilidad mecánica proporcionada en todas las articulaciones, lo que aumenta la seguridad en las interacciones físicas con el entorno y la protección del propio robot. Para ello se ha introducido un compacto y simple mecanismo de transmisión por muelle entre el eje del servo y el enlace de salida. La estructura en aluminio de los brazos ha sido cuidadosamente diseñada de forma que los actuadores estén aislados frente a cargas radiales y axiales que los puedan dañar. El manipulador desarrollado ha sido validado a través de experimentos en base fija y en pruebas de vuelo en exteriores.Ministerio de Economía y Competitividad; DPI2014-5983-C2-1-

Towards Mobility-as-a-Service: a cross-case analysis of public authorities' roles in the development of ICT-supported integrated mobility schemes

Automobiles have become counter-productive. Negative externalities resulting from car use have overcome the social benefits automobiles brought when initially introduced. Having shaped most contemporary transportation systems, the automobility regime is known to be hard to revert from. However, as all path-dependent systems, automobility can be subject to tipping points. Among other elements, the Information and Communication Technologies (ICTs) have enabled the development of new solutions having the potential to support a paradigm shift. At the forefront of ICT-enabled developments, so-called ICT-supported integrated mobility schemes have emerged, encompassing smart transportation cards, Integrated Mobility Platforms and Mobility-as-a-Service, that bundle different transport offers together and aim at providing users with a mobility solution of a level of service competitive with the one provided by private cars, ultimately holding the promise of supporting a shift from vehicle ownership to mobility usership and potentially help unlatching transportation systems from the current automobility lock-in. However, most of those solutions are being proposed by the private sector, which often has different interests than the public sector. While the organization of transport usually falls under the responsibility of public actors, new governance structures are needed in order to make the most out of ICT-supported integrated mobility schemes. Hence, this thesis aims at shedding light on the role that public bodies are playing into the birth of smart cards, integrated mobility platforms and MaaS, and more specifically on the way they are governing their development. A case study strategy was employed in this thesis, where, building on grey literature and semi-structured interviews, the cases of smart cards development in London, integrated mobility platform unfolding in Vienna and Mobility-as-a-Service expansion in Helsinki served as empirical material. Based on a cross-case analysis conducted using governance and socio-technical transition literature, the main findings of this thesis are that (i) public transport authorities and state-owned railway undertakings are usually quite reluctant to ICT-supported integrated mobility schemes brought by external actors and prefer developing those by themselves and stay in control or avoid collaborating; (ii) central governments can act as true enablers by developing visions including strong quantitative targets, showing political support for those solutions, acting as matchmakers between public and private bodies, developing legislation, providing funding and steering, and using network governance to make incumbent regime actors change behaviors; (iii) city governments have a greater role to play by setting stronger quantitative-based visions and stop governing by laissez-faire; (iv) ICT-supported integrated mobility schemes should not be understood as magic bullets and must be combined with demand management policies to be truly effective. By providing thick-descriptions of the nuts and bolts of smart cards, IMP and MaaS development, this thesis contributes to the literature on transport integration, transport governance and socio-technical transitions, and contributes to practice by suggesting fourteen recommendations for public authorities interested in a sustainable and impactful development of ICT-supported integrated mobility schemes