Joint near-lossless compression and watermarking of still images for authentication and tamper localization

A system is presented to jointly achieve image watermarking and compression. The watermark is a fragile one being intended for authentication purposes. The watermarked and compressed images are fully compliant with the JPEG-LS standard, the only price to pay being a slight reduction of compression efficiency and an additional distortion that can be anyway tuned to grant a maximum preset error. Watermark detection is possible both in the compressed and in the pixel domain, thus increasing the flexibility and usability of the system. The system is expressly designed to be used in remote sensing and telemedicine applications, hence we designed it in such a way that the maximum compression and watermarking error can be strictly controlled (near-lossless compression and watermarking). Experimental results show the ability of the system to detect tampering and to limit the peak error between the original and the processed images.     

3D model of a sector of the South Scotia Ridge (Antarctica)

A three-dimensional geological model was built to show and analyse a northern sector of the Scotia–Antarctica transform plate boundary.The South Scotia Ridge is a 400 km long submerged continental structural high representing the eastern continuation of the Antarctic Peninsula. South Scotia Ridge runs approximately in the E–W direction, separating Scotia Sea Plate from Antarctica Plates. Structures, due to the transform plate margin, are considered to be concentrated inside this continental high. The three-dimensional model, built using seismic profiles and a digital elevation model, is a powerful tool to visualize and help to understand deep geological structures. Maps and profiles, on the contrary, only give a two-dimensional view, and do not show the structure of the continental–oceanic boundary at depth.The model shows that the deformation style of the continental–oceanic boundary, and of the oceanic crust nearby, is related to the left-lateral movement of the main transform fault system. Furthermore, it seems to be connected to the orientation and geometry of the South Scotia Ridge with respect to the homogeneous deformation regime, which affects the entire Scotia Plate. Moving from west to east, the NW-dipping main fault surface becomes almost vertical with a sinistral strike–slip movement in the central sector. To the east, a south-dipping plane decreases its inclination and changes orientation (from E–W to ESE–WNW): here shortening features are visible.The three-dimensional geological model presents a western and central province wherein the continental–oceanic boundary involves the fragmented continental blocks, the continental slope, the oceanic basement and sediments. The sedimentary cover and the oceanic basement are not deformed in the eastern province.     

Sol–Gel Processing and Characterization of Pure and Metal-Doped SnO2 Thin Films

A chloride-based inorganic sol–gel route was used for preparing pure and metal (osmium, nickel, palladium, platinum)-doped SnO₂ sol. SnCl₄ was first reacted with propanol, then the resulting compound was hydrolyzed and subsequently mixed with solutions of the metal dopants. The obtained sols were used for depositing thin films by spin coating or for preparing powders by solvent evaporation at 110°C. FTIR spectroscopy and thermal analysis of the powders revealed that chlorine still bound to tin stabilized the sol against gelation by hindering the condensation reactions. Film characterizations showed that platinum and palladium, unlike nickel and osmium, were likely to form nanoparticles in the SnO₂ lattice. This result was discussed with regard to the different ways that platinum and palladium, on one hand, and nickel and osmium, on the other, modified the growth of SnO₂ grains and the film roughness and morphology. Dopants that formed nanoparticles (platinum, palladium) resulted in the roughest film, while dopants that did not form particles (nickel, osmium) resulted in SnO₂ grain size very close to that of pure SnO₂.     

An infrastructure to support cooperation of knowledge-level agents on the semantic Grid

Can a Knowledge-Level layer be located in the Semantic Grid infrastructure? Is it possible to design an Agent Communication Language (ACL) which enables Knowledge-Level agents to cooperate in a geographically distributed Semantic Grid despite nodes’ failures or malfunctions? This paper tries to address the above Semantic Grid challenges presenting an agent-based Open Service Architecture which integrates geographically distributed agents in a Semantic Grid. The architecture is well integrated with standard Internet components and technologies and supports communication among Knowledge-Level agents. The role of agents is to retrieve, execute and compose available services providing more sophisticated instances of them. Inter-agent communication is realized by exploiting an advanced Agent Communication Language which supports a fault-tolerant anonymous interaction protocol and satisfies a set of well defined Knowledge-Level programming requirements. Here, we present the design of the architecture and of the Agent Communication Language as well as their implementation. The architecture is evaluated by means of several case studies which highlight the main feature of our proposal. The main advantage of our approach is to demonstrate that different issues, such as high level inter-agent communication and fault tolerance, can be successfully integrated in Grid infrastructures which provide Web Services maintaining a clean design of the architecture and a Knowledge-Level characterization.     

The general fault detection and isolation problem for 2D state-space models

In this paper, the fault detection and isolation problem for two-dimensional (2D) state-space models is investigated in a rather general setting, by assuming that disturbances may affect the system. In a recent contribution [M. Bisiacco, M.E. Valcher, Observer-based fault detection and isolation for 2D state-space models, Multidim. Systems Signal Process 17 (2006) 219–242], a complete theory of dead-beat (possibly unknown input) observer-based fault detectors and isolators (FDIs) has been developed. Here the wider class of 2D FDIs, which allow to detect and identify possible faults, without requiring a preliminary state estimation, is introduced, and necessary and sufficient conditions for the existence of a dead-beat FDI are derived. Constructive procedures for obtaining such FDIs, and comparisons with the results obtained in [M. Bisiacco, M.E. Valcher, Observer-based fault detection and isolation for 2D state-space models, Multidim. Systems Signal Process 17 (2006) 219–242], are also provided.