Bounded Error Identification of Systems With Time-Varying Parameters

This note presents a new approach to guaranteed system identification for time-varying parameterized discrete-time systems. A bounded description of noise in the measurement is considered. The main result is an algorithm to compute a set that contains the parameters consistent with the measured output and the given bound of the noise. This set is represented by a zonotope, that is, an affine map of a unitary hypercube. A recursive procedure minimizes the size of the zonotope with each noise corrupted measurement. The zonotopes take into account the time-varying nature of the parameters in a nonconservative way. An example has been provided to clarify the algorithm

Robust MPC of constrained nonlinear systems based on interval arithmetic

A robust MPC for constrained discrete-time nonlinear systems with additive uncertainties is presented. The proposed controller is based on the concept of reachable sets, that is, the sets that contain the predicted evolution of the uncertain system for all possible uncertainties. If processes are nonlinear these sets are very difficult to compute. A conservative approximation based on interval arithmetic is proposed for the online computation of these sets. This technique provides good results with a computational effort only slightly greater than the one corresponding to the nominal prediction. These sets are incorporated into the MPC formulation to achieve robust stability. By choosing a robust positively invariant set as a terminal constraint, a robustly stabilising controller is obtained. Stability is guaranteed in the case of suboptimality of the computed solution. The proposed controller is applied to a continuous stirred tank reactor with an exothermic reaction.Ministerio de Ciencia y Tecnología DPI-2001-2380-03- 01Ministerio de Ciencia y Tecnología DPI-2002-4375-C02-0

Improved MPC Design based on Saturating Control Laws

This paper is concerned with the design of stabilizing model predictive control (MPC) laws for constrained linear systems. This is achieved by obtaining a suitable terminal cost and terminal constraint using a saturating control law as local controller. The system controlled by the saturating control law is modelled by a linear difference inclusion. Based on this, it is shown how to determine a Lyapunov function and a polyhedral invariant set which can be used as terminal cost and constraint. The obtained invariant set is potentially larger than the maximal invariant set for the unsaturated linear controller, O∞. Furthermore, considering these elements, a simple dual MPC strategy is proposed. This dual-mode controller guarantees the enlargement of the domain of attraction or, equivalently, the reduction of the prediction horizon for a given initial state. If the local control law is the saturating linear quadratic regulator (LQR) controller, then the proposed dual-mode MPC controller retains the local infinite-horizon optimality. Finally, an illustrative example is given

Aves acuáticas de la Mar Chica de Melilla, julio 1977, junio 1978 y verano 1979

Durante 1978 y 1979 se hizo una serie de observaciones sobre aves acuáticas en la Mar Chica (Melilla). En conjunto se contaron 32 especies diferentes, siendo la más abundante: Charadrius alexandrinus, Limosa limosa, Tringa totañus y T. hypoleucos. Algunas de ellas, así como Haematopus ostralegus y Arenaria interpres dejan algunos individuos en época invernal. La especie más abundante fue Fulica atra, con más de 2.000 individuos en enero.Some observations on waterfowl in the Mar Chica (Melilla) during 1978 and 1979, was made. 32 different species has been seen, being the four more abundant: Charadrius alexandrinus, Limosa limosa, Tringa totanus and T. hypoleucos. A few of them, as well as some Haematopus ostralegus and Arenaria interpres remain in winter season. The most abundant species was Fulica atra, with more than 2.000 specimens in January

Optimal Operation of Pipeline Transportation Systems

11th Triennial World Congress. Tallinn. Estonia. USSR. 1990This paper presents a simulator of an oil pipeline for scheduling purposes. The simulator includes an algorithm for optimizing the energy operating costs. The optimization algorithm works in two steps. The first one consists of the computation of a function that measures the estimated mininltun cost to the goal node. This computation involves the use of Bellman's optimality principle and of some heuristic rules in order to avoid the combinatorial explosion. During the second step the optinltmum trajectory is obtained with the help of the function mentioned above and using an accurate simulation of the transportation system. The simulation considers those aspects which are relevant t.o the optimization problem and takes into account the following factors: topology and topography of the network. non-linear characteristics of pumps and pipelines, variable demands of consumers, time changing prices of electrical energy and hydraulic equations throughout the system. The simulator is being used by CAMPSA (the major oil distribution company in Spain) Some results obtained with an oil pipeline system in Northern Spain are presented in the paper

Characterization of plant growth promoting bacteria (PGPR) isolated from the rhizosphere of Arthrocnemum macrostachyum.

Motivation: The recent boom in organic agriculture has awakened the need to find alternative methods to chemical products. PGPRs (plant growth-promoting rhizobacteria) are rhizospheric bacteria that contribute in a favourable way for the plant development through different mechanisms like exudates production (that enhance plant rooting), nutrient solubilization or resistance to pathogenic agents (1). The study of these microorganisms and its subsequent use for different agriculture requirements is a viable option in order to get good results in a more sustainable way. In addition, it is an interesting approach to promote the soil regenerative abilities of some plants, like the halophyte Arthrocnemum macrostachyum (2).Methods: Bacteria from the rhizosphere of A. macrostachyum were isolated from plants grown in different areas at the Lebrija marshes. 5 µl of exponentially bacterial cultures were dropped onto Petri dishes containing different media: CAS to test siderophores production (3), PVK for phosphate solubilization (3), nutrient broth supplemented with NaCl for testing tolerance to sodium chloride and nutrient broth with 0,5mM and 1mM Zn concentrations to test heavy metal resistance. All of them were incubated at 28ºC for 72h. Acyl-homoserine lactone and indolacetic acid (IAA) production tests (3) were also performed. In addition, 5 µl droplets of each bacterial suspension were spotted on Petri dishes together with a disk of active Macrophomina phaseolina culture to test antifungal activity.Results: A total of 203 strains were isolated from the rhizosphere of A.macrostachyum plants. In CAS medium, 40% of them formed an orange-yellowish halo, denoting siderophore production. In PVK medium, 7% shown a transparent halo, indicating phosphate solubilization ability. 30% of the strains were auxin producers, while only a 13% exhibited the quorum sensing mechanism. 3% of all the strains displayed high halotolerance, showed positive growth in 24 % (p/v) NaCl. 5% and 3% of the strains were able to grow in the presence of 0,5 and 1 mM Zn, respectively. Taking into account fungicide activity, 11% of the bacterial isolates are able to inhibit the growth of the pathogenic fungus M. phaseolina.Conclusions: An earlier conclusion of this incipient study is that the rhizosphere of halophyte plants living in natural stressing areas is a good source for isolating bacteria with desirable properties to be used as PGPR and also for the control of pathogenic fungus

Determining astrophysical three-body radiative capture reaction rates from inclusive Coulomb break-up measurements

A relationship between the Coulomb inclusive break-up probability and the radiative capture reaction rate for weakly bound three-body systems is established. This direct link provides a robust procedure to estimate the reaction rate for nuclei of astrophysical interest by measuring inclusive break-up processes at different energies and angles. This might be an advantageous alternative to the determination of reaction rates from the measurement of B(E1) distributions through exclusive Coulomb break-up experiments. In addition, it provides a reference to assess the validity of different theoretical approaches that have been used to calculate reaction rates. The procedure is applied to Li11 (Li9+n+n) and He6 (He4+n+n) three-body systems for which some data exist.This work has been partially supported by the Spanish Ministerio de Economía y Competitividad and the European Regional Development Fund (FEDER) under Projects No. FIS2011-28738-c02-01, No. FIS2013-41994-P, No. FPA2013-47327- C2-1-R, No. FIS2014-53448-c2-1-P, and FIS2014-51941-P and by Junta de Andalucía under Group No. FQM-160 and Project No. P11-FQM-7632. J. Casal acknowledges support from the Ministerio de Educacion, Cultura y Deporte, FPU Research Grant No. AP2010-3124. M. Rodríguez-Gallardo acknowledges postdoctoral support from the Universidad de Sevilla under the V Plan Propio de Investigacion, Contract No. USE-11206-M.Peer Reviewe

Biocontrol characterization of a bacterial collection by means of enzymatic activities and confrontation assays

Currently, there is an increasing agriculture demand, not only for human consumption, but also for feeding the cattle. This provokes an overuse of fertilizers and fungicides to maintain the standards of market and production which in turns causes serious environmental problems. Stimulated by these facts, we think that a possible solution could be the use of bacteria with PGPR activities (plant growth-promoting rhizobacteria) as well as biocontrol activities against pathogenic fungi, in order to reduce or to eliminate, in the future, the use of these harmful products.Bacteria used in this work belong to the bacterial collection of the IFAPA the Torres-Tomejil Center, and have been previously characterized by their PGP activities and for their aptitude to inhibit the in vitro growth of the phytopathogenic fungus Macrophomina phaseolina. In this study, the bacterial isolated were screened for their biocontrol enzymatic activities (catalase, oxidase, protease, amylase, chitinase and β-glucanase), as well as for hydrocyanic acid production. After that, an in vitro confrontation assay was carried out against F. oxysporum and F. proliferatum, with the bacterial strains that gave good results in biocontrol activities.From a total of 40 strains possessing enzymatic activities, the following strains have shown the higher values: strain Hr4b (nd) exhibited high cellulose, protease and amylase activities; strain B1-2a (Bacillus erophilus) possessed protease and amylase activities; C11 (non determined -nd-) and AdB1 (nd) enhanced in cellulase and protease activities; strain Hvs2 (Bacillus licheniformis) highlighted for its cellulose activity and CT197 (nd) for its chitinase one. In addition, all of them exhibited other enzymatic activities in a lesser extent. Regarding the in vitro confrontation experiment against F. oxysporum and F. proliferatum, the strains CT3 (Pseudomonas fluorecens), CT19 (Pseudomonas fluorecens), CT131 (Pseudomonas fluorecens), Hvs2, Hvs 6 (Streptomices fradiae) and Hvs 8 (Brevibacterium frigoritolerans), were found to be highly inhibitory of both fungal strains growth.As conclusion, strains CT3, CT19, CT131, Hvs2, Hvs6 and Hvs8 could be candidates to be used as biocontrol agents against phytopathogen fungi. Futures studies will be focused on investigating a commercial product able to be used under field conditions

Leather: a contribution to sustainable goat production

Brazilian Northeast is a potentially good skin producer region due to its livestock farming activities which include more than 90% national goat cense. This exceptional situation with plenty raw material at hand, enables the development of familiar exploitations of goat skin tannery, thus recovering an activity linked to ancestral culture. Misevaluation of leather both by producers and industry, added to unstructured production and lack of research aimed to improve the quality of the final product could be key factors to the poor development of goat leather manufacture up to now in Northeast Brazil. Nevertheless, once transformed this product is reaching high values in international and Brazilian national markets, thus permitting it to became an important income source in the disfavoured Brazilian northeastern arid regions. If producers become aware of the value of their leather and if they are duly remunerated, industry will be offered better products and society will improve employment and performance. The main objective of the present paper is to contribute to point out the possibilities of leather production in the development of goat farming communities form disfavoured regions as a tool to improve the dignity and the quality of life of the producers. Moreover, the development of tannery in rural regions could help to the conservation of animal genetic resources (AGR) of local goat breeds thus contributing to sustainable development in arid or degraded regions.O Nordeste brasileiro, pela sua condição de região agropecuária, é potencialmente bom produtor de peles, superando 90% da população caprina nacional. Esta situação privilegiada, com a matéria-prima ao alcance da indústria coureira, pode permitir o desenvolvimento do curtume de peles de caprino de exploração familiar. Isto representaria a recuperação dessa atividade vinculada a uma cultura tradicional e a garantia de empregos numa região carente. A desvalorização da pele, como produto, pelo produtor e pela indústria, associada à desestruturação da produção, inexistência de cadeia produtiva e carência de pesquisa que contribua para obtenção de um produto de qualidade, são pontos críticos do freio no desenvolvimento da indústria de transformação da pele caprina. Porém, esta matéria-prima alcança alto valor no mercado internacional e nacional brasileiro, como produto transformado, sendo importante fonte de renda. Por isso, enquanto não houver consciência por parte do produtor e não houver remuneração justa da sua atividade, perde a indústria, pela oferta de matéria-prima de menor qualidade e, indiretamente, perde a sociedade, pela falta de geração de emprego e renda. O objetivo principal deste trabalho é contribuir para discussão das possibilidades sobre a produção do couro no desenvolvimento das comunidades caprinocultoras de zonas desfavoráveis do semi-árido nordestino, como ferramenta na melhoria da dignidade e qualidade de vida dos produtores. Além de tudo, o desenvolvimento do curtume em zonas rurais permitiria a conservação dos recursos genéticos animais de caprinos autóctones, contribuindo na direção da pesquisa para o desenvolvimento sustentável

Biología y racionalidad. El carácter distintivo del cuerpo humano

¿Cuáles son los componentes distintivos del cuerpo humano que permiten identificarlo como un elemento material diferente del resto del mundo físico? ¿Son tales elementos algo meramente funcional, o remiten a otra dimensión que va más allá de la instrumentalidad? Estas son las preguntas que se plantean en el libro “Biología y racionalidad. El carácter distintivo del cuerpo humano” de José Ángel Lombo y José Manuel Giménez Amaya. Partiendo desde la perspectiva filosófica, los autores buscan clarificar estas cuestiones ofreciendo un marco conceptual interdisciplinar que remite en todo momento a la unidad de la persona humana.Which are the distinctive parts of the human body that help us to identify it as a physical element diverse from the rest of the world? Are they simply functional elements, or do they refer to another dimension that goes beyond instrumentality? These are the questions posed in the book “Biology and Rationality: The Distinctive Character of the Human Body” by José Ángel Lombo and José Manuel Giménez Amaya. From a philosophical point of view, the authors seek to clarify these issues by offering an interdisciplinary conceptual framework always referred to the unity of the human person