Honey-bee mating optimization (HBMO) algorithm for optimal reservoir operation

In recent years, evolutionary and meta-heuristic algorithms have been extensively used as search and optimization tools in various problem domains, including science, commerce, and engineering. Ease of use, broad applicability, and global perspective may be considered as the primary reason for their success. The honey-bee mating process has been considered as a typical swarm-based approach to optimization, in which the search algorithm is inspired by the process of real honey-bee mating. In this paper, the honey-bee mating optimization (HBMO) algorithm is presented and tested with a nonlinear, continuous constrained problem with continuous decision and state variables to demonstrate the efficiency of the algorithm in handling the single reservoir operation optimization problems. It is shown that the performance of the model is quite comparable with the results of the well-developed traditional linear programming (LP) solvers such as LINGO 8.0. Results obtained are quite promising and compare well with the final results of the other approach.     

Circles and Communities,Sharing Practices and Learning: Looking at New Extension Education Approaches

Abstract

Purpose

Information technology (IT) has tremendous potential for fostering grassroots development and the Indian government has created various capital-intensive computer networks to promote agricultural development. However, research studies have shown that information technology investments are not always translated into productivity gains due to poor computer use by employees. In this context, a research investigation was conducted to develop a Computer Utilization Model that explains how individual and organizational factors influence computer utilization in extension organizations in India.     

From the disjunction between passive and active instruction approaches towards their integration as an alternative for the significant learning of sustainable development / De la disyuntiva entre los enfoques de instrucción pasiva y activa hacia su integración como alternativa para un aprendizaje significativo del desarrollo sostenible

Abstract

This study aims to show how the integration of passive and active learning approaches contributes towards the significant understanding of problems associated with sustainable development. To do this, a case study from the municipality of San Miguel de Achiutla in Oaxaca, Mexico, is used as a general method, with the specific procedure including an instrument based on secondary sources representing the passive learning phase, as well as an instrument created on the basis of primary sources, designed in relation to the active learning component. The passive learning phase enabled us to identify variables pertaining to the highly vulnerable dimensions of sustainable development, and to also detect areas in which there is a deficit of information, since not all data are available, while the active learning phase revealed the causes of vulnerability from the perspective of different agents, including those who experienced the issues directly. In view of the above, we conclude that rather than being exclusive, these two different approaches should in fact be complementary.     

¿Usos cotidianos o usos enlatados? Enseñar y evaluar la lectoescritura a sujetos reales y mentes flexibles

En el campo del lenguaje y la lectoescritura, la renovación educativa parece estar situándose en la batalla por el diseño abierto y la evaluación informal. En este artículo se propone un modelo teórico para la lectoescritura flexible que pueda soportar las posibilidades que se abren y evitar los inconvenientes que amenazan a los actuales métodos informales de renovación a los que está dedicado el tema central de este número.     

Stability of switching linear systems with switching signals driven by stochastic processes

This paper presents conditions to assure the exponential stability in probability for autonomous switching linear systems. The switching signal acting on the autonomous system produces intervals that follow independent, identically distributed stochastic processes—the stability then follows by verifying simple-to-check linear matrix inequalities.     

Cytocompatible cellulose nanofibers from invasive plant species Agave americana L. and Ricinus communis L.: a renewable green source of highly crystalline nanocellulose

In this study, the fibers of invasive species Agave americana L. and Ricinus communis L. were successfully used for the first time as new sources to produce cytocompatible and highly crystalline cellulose nanofibers. Cellulose nanofibers were obtained by two methods, based on either alkaline or acid hydrolysis. The morphology, chemical composition, and crystallinity of the obtained materials were characterized by scanning electron microscopy(SEM) together with energy-dispersive X-ray spectroscopy(EDX), dynamic light scattering(DLS), X-ray diffraction(XRD), and Fourier transform infrared(FTIR)spectroscopy. The crystallinity indexes(CIs) of the cellulose nanofibers extracted from A. americana and R. communis were very high(94.1% and 92.7%, respectively). Biological studies evaluating the cytotoxic effects of the prepared cellulose nanofibers on human embryonic kidney 293 T(HEK293 T) cells were also performed. The nanofibers obtained using the two different extraction methods were all shown to be cytocompatible in the concentration range assayed(i.e., 0-500 μg/mL). Our results showed that the nanocellulose extracted from A. americana and R. communis fibers has high potential as a new renewable green source of highly crystalline cellulose-based cytocompatible nanomaterials for biomedical applications.     

Chebyshev polynomial solutions of systems of higher-order linear Fredholm-Volterra integro-differential equations

A Chebyshev collocation method, an expansion method, has been proposed in order to solve the systems of higher-order linear integro-differential equations. This method transforms the IDE system and the given conditions into the matrix equations via Chebyshev collocation points. By merging these results, a new system which corresponds to a system of linear algebraic equations is obtained. The solution of this system yields the Chebyshev coefficients of the solution function. Some numerical results are also given to illustrate the efficiency of the method. Moreover, this method is valid for the systems of differential and integral equations.     

Going to action? A literature review on educational proposals in formal Environmental Education

The current state of the planet’s environmental deterioration calls for formal educational contexts to implement effective environmental proposals which nurture action competence. The aim of this paper is to examine the educational proposals in formal contexts that have been published in the two research journals of greatest impact on Environmental Education during the period 2008–2013, and to analyse how they contribute to the development of action competence. Special attention is paid to research (i) based on real participation by students; (ii) promotes reflection on the complexity of environmental issues; (iii) facilitates critical thinking; (iv) encourages autonomous and responsible decision-making and (v) involves communities. Our results show that these approaches can help improve the development of action-focused environmental education and bring to light a series of challenges for future research.     

Some recent Unesco publications

Notes and Reviews

Some recent Unesco publications