On the dynamics of the Furuta pendulum

The Furuta pendulum, or rotational inverted pendulum, is a system found in many control labs. It provides a compact yet impressive platform for control demonstrations and draws the attention of the control community as a platform for the development of nonlinear control laws. Despite the popularity of the platform, there are very few papers which employ the correct dynamics and only one that derives the full system dynamics. In this paper, the full dynamics of the Furuta pendulum are derived using two methods: a Lagrangian formulation and an iterative Newton-Euler formulation. Approximations are made to the full dynamics which converge to the more commonly presented expressions. The system dynamics are then linearised using a Jacobian. To illustrate the influence the commonly neglected inertia terms have on the system dynamics, a brief example is offered.Benjamin Seth Cazzolato and Zebb Prim

Quality of Service for Information Access

Information is available in many forms from different sources, in distributed locations; access to information is supported by networks of varying performance; the cost of accessing and transporting the information varies for both the source and the transport route. Users who vary in their preferences, background knowledge required to interpret the information and motivation for accessing it, gather information to perform many different tasks. This position paper outlines some of these variations in information provision and access, and explores the impact these variations have on the user’s task performance, and the possibilities they make available to adapt the user interface for the presentation of information

The equilibrium melting of polymers

Equilibrium melting of polymer

Quantification of Residual Stresses in Electron Beam Welded Fracture Mechanics Specimens

Residual stress measurements have been made in a range of electron beam welded samples to study how the weld induced residual stresses redistributed during fabrication of compact tension, C(T), specimens. The samples were manufactured from Type 316H stainless steel in the ex-service material condition and in material which had been preconditioned by inducing 8% plastic strain. Measurements made using neutron diffraction, slitting and the contour method were generally in good agreement and showed residual stress components of up to three times the base material's yield strength existed in the samples. When sectioning a sample to perform the contour method, large elastic deformations occurred at the cut tip due to the large residual stresses present. A correction was applied to the measured surface displacements to account for this deformation. Neutron diffraction measurements were made at various stages of the fabrication process, which showed significant stress redistribution occurred as the welded samples were machined into C(T) specimens. However the tensile stresses near the crack tip of the C(T) specimens remained large and could significantly influence subsequent crack growth tests

Rainwater harvesting, alternative to the water supply in Indian urban areas : The case of Ahmedabad in Gujarat

Water scarcity is a characteristic of north-western states of India, such as Gujarat. Over time, the continuous increase of the population as well as the financial, administrative and technical deficiencies of the new supply system have lead to the deterioration of the water service in the city. In the meantime, the water demand has considerably increased due to the improvement of standards of living. This has resulted in an increasing pressure on underground water resources, which has lead to an alarming depletion of aquifers. From this overall situation arises the question of the use of complementary alternative sources of water in Ahmedabad and more particularly of the rehabilitation of the rainwater harvesting structures still existing in its old city area. The objective of the research is to evaluate to what extent this traditional system may constitute an additional source of water within the Old city of Ahmedabad and may locally reduce the pressure on water demand, assuming that the existing supply system does not fulfil the needs of the users. The results of an exploratory field study conducted in the Old city in 2001-02, which combined quantitative and qualitative aspects, give an outlook on people's opinions and behaviors regarding both systems. Finally, the rehabilitation of rainwater harvesting structures in the Old city of Ahmedabad suggests the necessity of empowering local structures of water management (households, non governmental association) in semi-arid urban areas to create the conditions for a sustainable implementation.rainwater harvesting ; water supply ; water scarcity ; water management ; Ahmedabad Old City ; Pol ; Gujarat ; India

NOEMI, a collaborative management for ICT process improvement in SME: experience report

This paper relates to an R&D project – called NOEMI – aiming to propose to SME’s a collaborative management of their respective information systems in terms of quality, reliability and cost. The targeted SME are those without IT dedicated internal staff. The model developed in the project focuses on the usual IT activities of the SME’s, which are classified in five domains: infrastructure, support, management, security, and documentation. The NOEMI model has been successfully experimented with PME partners for validation pur-pose. This paper insists on the experimentation of the NOEMI model. The results are discussed and compared with other classical solutions usually encountered within IT practices of SME’s. The last part of the paper draws the perspectives opened with the model according to the results of its experimentation.IT Service Management, collaborative management, SME, process assessment, process improvement.

Rainwater Harvesting, Alternative to the Water supply in Indian Urban Areas : the Case of Ahmedabad in Gujarat.

NAgestion de l'eau;développement;récupération de l'eau de pluie;Inde

Soutenabilité de l'agriculture maraîchère dans les hautes vallées de Puebla (Mexique): enjeux au fil de l'eau. (Axe III, Symposium 10)

Las tierras altas tropicales han experimentado en las últimas décadas transformaciones importantes en sus sistemas de producción agrícolas, a través del desarrollo de la horticultura con riego campesino. La región de Puebla (México) ofrece un buen ejemplo de estas reconfiguraciones. No obstante, esas dinámicas hortícolas tienen varias limitaciones tanto en el ámbito socio-económico como ambiental, de las cuales habría que medir el alcance, poniendo en tela de juicio su sostenibilidad. El propósito de este artículo es, tomando los recursos hídricos y su acceso como objeto central y gracias a los primeros resultados de nuestras investigaciones en la zona (2009-2010), aportar unos elementos para el entendimiento de esta problemática.Dans le monde et particulièrement en Amérique latine, les hautes terres tropicales font l'objet de profondes transformations de leur système de production agricole, à travers l'apparition ou le développement d'une agriculture intensive de type maraîchère, elle-même liée à une extension de l'irrigation. La région de Puebla, au Mexique, offre un exemple caractéristique de ces mutations agricoles. L'accès aux ressources en eau, tant en quantité qu'en qualité, constitue une condition indispensable à l'existence comme à la poursuite de ces activités. Mesurer la disponibilité de l'eau permet donc de questionner la soutenabilité de ce type d'agriculture. Quels sont les facteurs socio-économiques ou environnementaux limitant l'accès à l'eau ? Ces limites peuvent elles aller jusqu'à remettre en cause cette agriculture maraîchère ? Les travaux de terrain effectués dans cette région en 2009 et 2010 nous permettent d'apporter quelques éléments de réponse