Image-based localization and pose recovery using scale invariant features

In this paper, we propose a vision based mobile robot localization strategy. Local scale-invariant features are used as natural landmarks in unstructured and unmodified environment. The local characteristics of the features we use prove to be robust to occlusion and outliers. In addition, the invariance of the features to viewpoint change makes them suitable landmarks for mobile robot localization. Scale-invariant features detected in the first exploration are indexed into a location database. Indexing and voting allow efficient recognition of global localization. The localization result is verified by epipolar geometry between the representative view in database and the view to be localized, thus the probability of false localization will be decreased. The localization system can recover the pose of the camera mounted on the robot by essential matrix decomposition. Then the position of the robot can be computed easily. Both calibrated and un-calibrated cases are discussed and relative position estimation based on calibrated camera turns out to be the better choice. Experimental results show that our approach is effective and reliable in the case of illumination changes, similarity transformations and extraneous features. © 2004 IEEE.

Rotation Numbers Of Invariant Manifolds Around Unstable Periodic Orbits For The Diamagnetic Kepler Problem

In this paper, a method to construct topological template in terms of symbolic dynamics for the diamagnetic Kepler problem is proposed. To confirm the topological template, rotation numbers of invariant manifolds around unstable periodic orbits in a phase space are taken as an object of comparison. The rotation numbers are determined from the definition and connected with symbolic sequences encoding the periodic orbits in a reduced Poincare section. Only symbolic codes with inverse ordering in the forward mapping can contribute to the rotation of invariant manifolds around the periodic orbits. By using symbolic ordering, the reduced Poincare section is constricted along stable manifolds and a topological template, which preserves the ordering of forward sequences and can be used to extract the rotation numbers, is established. The rotation numbers computed from the topological template are the same as those computed from their original definition.

On the invariant representation of spin tensors with applications

The invariant representation of the spin tensor defined as the rotation rate of a principal triad for a symmetric and non-degenerate tensor is derived on the basis of the general solution of a linear tensorial equation. The result can be naturally specified to study the. spin of the stretch tensors and to investigate the relations between various rotation rate tensors encountered frequently in modern continuum mechanics. A remarkable formula which relates the generalized stress conjugate to the generalized strain in Hill's sense. to Cauchy stress, is obtained in invariant form through the work conjugate principle. Particularly, a detailed discussion on the time rate of logarithmic strain and its conjugate stress is made as the principal axes of strain arc not fixed during deformation.

Constant mean curvature hypersurfaces with constant δ-invariant

We completely classify constant mean curvature hypersurfaces (CMC) with constant δ-invariant in the unit 4-sphere S4 and in the Euclidean 4-space E4.

Benchmarking en responsabilidad social corporativa. El caso de las empresas gallegas

[ES] En el presente trabajo se realiza una revisión del concepto de responsabilidad social. Posteriormente se analizan las posibilidades y problemas de la utilización del benchmarking en RSE haciendo un análisis de las últimas investigaciones que desarrollaron algún método de benchmarking. A partir de ese análisis se propone un indicador homogéneo que evalúa 68 aspectos relacionados con los diferentes stakeholders implicados en RSE. También se recoge información sobre la importancia otorgada por las empresas encuestadas a estos aspectos.

El benchmarking aplicado a la gestión de la innovación

La gestión de la innovación es uno de los más importantes desafíos a los que se enfrentan los gestores empresariales. Numerosas instituciones y agentes del ámbito público, como privado (académicos,gobiernos, consultoras,agencias de desarrollo regional, centros tecnológicos, etc.) han propuesto y han elaborado modelos para ayudar a desenmarañar el reto de la innovación y para poder realizar una gestión eficaz de la misma. Este artículo sugiere el empleo de los modelos de gestión de la innovación para la realización de ejercicios de evaluación comparativa o benchmarking de diagnóstico que permitan mejorar la capacidad de gestión de la innovación de las organizaciones.