“A method for the optimal determination of the transmissivity function in a model of a horizontal two‐dimensional saturated aquifer, using time histories of the heads at a number of observation points, is developed. In this method the transmissivity function is assumed to be represented by a continuous spline surface over the entire domain of the aquifer and is given in terms of unknown nodal values disposed over a rectangular grid. These nodal values are then determined by requirements of optimality, i.e., by minimization of an error functional denoting the deviations of the observed and predicted heads at several strategically distributed observation wells. The method is complemented by using a hierarchical identification approach which consists of gradually increasing the number of nodal values employed in the analytical representation of the transmissivity function.”

“This paper deals with the development of efficient identification methods for the determination of parameters associated with the nonlinear response of structural systems subject to seismic conditions. The equation of motion of the system is given by M u ̈+ h (/. u, u, a)= p (t), where the external force vector p and the mass matrix M are assumed to be known. Also given is an observation vector w, consisting of some or all of the components of u, the vector of the nodal displacements. The vector function h, denoting the restoring forces of the mechanical system, is parametrically given in terms of a constant vector a. Three different methods are presented for the determination of the parameters governing the vector function h. The first one is a direct approach requiring the unknown coefficients to appear linearly in the model equation. ”

“Energy deeply influences people’s lives and is an engine for social development and economic growth. Over the centuries, energy has helped transform societies and has underpinned human development. Energy contributes to fulfilling the most basic human needs, including nutrition, warmth, and light. Furthermore, there is ample evidence that access to reliable, efficient, affordable, and safe energy carriers can directly affect productivity, income, and health, and can enhance gender equity, education, and access to other infrastructure services. However, energy use patterns, in terms of both quality and quantity, are highly inequitably distributed on all sides of the development divide–North and South, rich and poor, men and women, rural and urban. This inequity in energy access and use compromises human welfare and has adverse impacts on the environment.

“The uncertain quest: science, technology, and development Food and Agriculture Organization of the United Nations Discover About FAO News Multimedia Main topics Statistics Members Publications English العربية Español Français Русский 中文 AGRIS - International System for Agricultural Science and Technology About AGRIS Contribute Acceptable use policy facebook linkedin twitter weibo Close Advanced Search The uncertain quest: science, technology, and development 1994 Salomon, J.-J. (ed.) | Sagasti, FR (ed.) | Sachs-Jeantet, C. (ed.) Summary (En) Show more [+] Less [-] AGROVOC Keywords changement technologique development policies recherche research scientifique scientists technological changes technologie technology technology transfer tecnologia transfert de technologie Bibliographic information Publisher Tokyo (Japan) United Nations Univ. Press Other Subjects investigacion;”