Search results for "TRANSFORMATION"

Bifurcations of Reachable Sets Near an Abnormal Direction and Consequences

2007

We describe precisely, under generic conditions, the contact and the bifurcations of the reachable set at time T along an abnormal direction, first for a single-input affine control system with constraint on the control, and then as an application for a sub-Riemannian system of rank 2. As a consequence we obtain in sub-Riemannian geometry a new splitting-up of the sphere near an abnormal minimizer γ into two sectors, bordered by the first Pontryagin’s cone along γ, called the L ∞-sector and the L 2-sector. Moreover we find again necessary and sufficient conditions of optimality of an abnormal trajectory for such systems, for any optimization problem.

Relativistic Positioning Systems in Flat Space-Time: The Location Problem

2013

The location problem in relativistic positioning is considered in flat space-time. When two formal solutions are possible for a user (receiver) of the system, its true location may be obtained from a standard set of emission data extended with an observational rule. The covariant expression giving the location of the user in inertial coordinates is decomposed with respect to an inertial observer.

Fully programmable display parameters in integral imaging by smart pseudoscopic-to-orthoscopic conversion

2011

Previously, we reported a digital technique for formation of real, non-distorted, orthoscopic integral images by direct pickup. However the technique was constrained to the case of symmetric image capture and display systems. Here, we report a more general algorithm which allows the pseudoscopic to orthoscopic transformation with full control over the display parameters so that one can generates a set of synthetic elemental images that suits the characteristics of the Integral-Imaging monitor and permits control over the depth and size of the reconstructed 3D scene.

Discrete-time static output-feedback semi-decentralized H<inf>∞</inf> controller design: An application to structural vibratio…

2012

In this work, we present a new and effective method to design discrete-time static output-feedback H ∞ controllers. This new method, based on a Linear Matrix Inequality (LMI) formulation, introduces a suitable transformation of the LMI variables that allows to obtain an explicit expression for the output-feedback gain matrix. Moreover, for problems involving a set of subsystems with information exchange constraints, a convenient structure on the LMI variables can be imposed in order to design semi-decentralized controllers, where the corresponding output-feedback gain matrix has a prescribed zero-nonzero structure. To illustrate the proposed methodology, discrete-time static velocity-feedba…

Induced ℓ<inf>2</inf> control of discrete-time Takagi-Sugeno fuzzy systems with time-varying delays via dynamic output feedback

2012

This paper is concerned with analyzing a novel model transformation of discrete-time Takagi-Sugeno (T-S) fuzzy systems with time-varying delays and applying it to dynamic output feedback (DOF) controller design. A new auxiliary model is proposed by employing a new approximation for time-varying delay state, and then delay partitioning method is used to analyze the scaled small gain of this auxiliary model. A sufficient condition on discrete-time T-S fuzzy systems with time-varying delays, which guarantees the corresponding closed-loop system to be asymptotically stable and has an induced l 2 disturbance attenuation performance, is derived by employing the scaled small gain theorem. Then the…

Citrus biotechnology

2020

Agricultural crops that can better withstand the changing climatic and pathogen landscape have been produced through natural selection throughout the millennia and, in recent years, through the process of human-assisted plant breeding and selection. However, a lack of genetic diversity in many commercially cultivated crops (due to monoculture) has made them more vulnerable to biotic and abiotic stresses (Esquinas-Alcazar, 2005; Keneni et al., 2012). Citrus, belonging to the Rutaceae family, is one of the most important commercial woody fruit crops in the tropical and subtropical areas of the world. The origin of citrus is traced back to parts of tropical and subtropical Southeast Asia (Wu e…

Genotoxicity of Terpenes Present in Wastewater of a Citrus Transformation Factory in Bacterial and Mammalian Cells and Effectiveness of Photocatalyti…

2010

The aim of this work was to compare the genotoxic responses of mixtures of terpenes present in wastewaters of a citrus transformation factory with the genotoxicity of the individual compounds. Samplings of wastewater collected before (untreated sample) and past water purification by biological method (treated sample) were analyzed using Solid Phase Micro-extraction (SPME) followed by GC analyses. The chromatograms showed in all effluents the presence of four terpenes: pinene, -pinene, 3-carene, D-limonene. The concentrations of terpenes in the untreated sample were 1–3 orders of magnitude higher than in the treated sample. Genotoxicity was evaluated in the Salmonella reversion assay (Ames t…

Stardust*

2010

Sistemi cibernetici per la ri-definizione dello spazio architettonico. Cedric Price e i laboratori del cambiamento

2020

This paper investigates the introduction of the cybernetic approach in architecture, through the key-role of N. Wiener, G. Pask and their influence on the projects of Cedric Price in the Sixties. The analysis of two of his most representative projects, such as the Fun Palace and the Generator, aims to individuate the informatics influence brought to the spatial composition. Furthermore, the article will clarify the visionary though of the British architect concerning the impact of digital infrastructures on the prefiguration of the most recent responsive and interactive approaches in architecture.

Las grandes Exposiciones en Europa: 1992-2002. Efectos duraderos sobre la ciudad y apropiación por parte de la ciudadanía.

2012

This paper studies the influence of great contemporary Expositions on the transformation of cities and of territories, developing some aspects we consider relevant of these events: their growing relevance in urban contemporary politics and the urban and architectural project as creator of the regeneration of abandoned or obsolete areas. Against the short duration of these events, the positive and negative effects, like the definition of new urban and territorial domains, the modernization of infrastructures and services, the impulse of private stakeholders toward building lands and the consolidation of City-Brand in tourism nets among others, have a much longer duration, and depend on the u…