An algebraic approach to the structural properties of positive state control systems

[EN] In this paper, we deal with discrete-time linear control systems in which the state is constrained to lie in the positive orthant R_+^n independently of the inputs involved, that is, the inputs can take negative values. Such (positive state) systems appear, for example, in ecology models where the removal of individuals from a population is described. Controllability and reachability are fundamental properties of a system that show its ability to move in space, which are analyzed from an algebraic point of view throughout the text, paying special attention to the single-input case.This work has been partially supported by Ministerio de Ciencia e Innovacion through Grants DPI-2013-46982-C2-1-R and MTM-2013-43678-P.Ricarte Benedito, B.; Romero Vivó, S. (2018). An algebraic approach to the structural properties of positive state control systems. Mathematical Methods in the Applied Sciences. 41(6):2370-2378. https://doi.org/10.1002/mma.4351S2370237841

Fourth Airborne Geoscience Workshop

The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection

Proceedings of the National Conference on Managing Irrigation for Environmentally Sustainable Agriculture in Pakistan, Islamabad, November 5-7, 1996. Volume I - Inauguration and deliberations

Irrigation managementSustainable agricultureEnvironmental effectsIrrigation canalsFarmer managed irrigation systemsWater distributionIrrigation efficiencyDrainageHydrologyWater reuseTube wellsSoil salinityWater tableWaterloggingGroundwater managementIrrigated farmingInstitution building

A first cubic upper bound on the local reachability index for some positive 2-D systems

[EN] The calculation of the smallest number of steps needed to deterministically reach all local states of an nth-order positive 2-D system, which is called local reachability index (ILR) of that system, was recently tackled bymeans of the use of a suitable composition table. The greatest index ILR obtained in the previous literature was n+3 ([n/2]) 2 for some appropriated values of n. Taking as a basis both a combinatorial approach of such systems and the construction of suitable geometric sets in the plane, an upper bound on ILR depending on the dimension n for a new family of systems is characterized. The 2-D influence digraph of this family of order n = 6 consists of two subdigraphs corresponding to a unique source s. The first one is a cycle involving the first n(1) vertices and is connected to the another subdigraph through the 1-arc (2, n(1) +n(2)), being the natural numbers n(1) and n(2) such that n(1) > n(2) = 2 and n-n(1)-n(2) = 1. The second one has two main cycles, a cycle where only the remaining vertices n(1)+1,..., n appear and a cycle containing only the vertices n(1)+1, n(1)+n(2)-1. Moreover, the last vertices are connected through the 2-arc (n(1) +n(2)-1, n). Furthermore, if n > 12 and is a multiple of 3, for appropriate n(1) and n(2), the ILR of that family is at least cubic, exactly, it must be n(3)+9n(2)+45n+108/27, which shows that some local states can be deterministically reached much further than initially proposed in the literature.We are gratefully thankful to the reviewers for their valuable remarks. This work has been partially supported by the European Union [FEDER funds] and Ministerio de Ciencia e Innovacion through Grants MTM-2013-43678-P and DPI2016-78831-C2-1-R.Bailo Ballarín, E.; Gelonch, J.; Romero Vivó, S. (2019). A first cubic upper bound on the local reachability index for some positive 2-D systems. Revista de la Real Academia de Ciencias Exactas Físicas y Naturales Serie A Matemáticas. 113(4):3767-3784. https://doi.org/10.1007/s13398-019-00699-0S376737841134Bailo, E., Gelonch, J., Romero-Vivo, S.: An upper bound on the reachability index for a special class of positive 2-D systems. Electron. J. Linear Algebra 18, 1–12 (2009)Bailo, E., Gelonch, J., Romero-Vivo, S.: Advances on the reachability index of positive 2-D systems. IEEE Trans. Autom. Control 59(8), 2248–2251 (2014)Bartosiewicz, Z.: Reachability and observability graphs for linear positive systems on time scales. IFAC Proc. Vol. 47(3), 3803–3808 (2014)Benvenuti, L., De Santis, A., Farina, L. (eds.): Positive Systems: Theory and Applications. Lecture Notes in Control and Information Sciences, vol. 294. Springer, Berlin (2003)Benvenuti, L.: On the reachable set for third-order linear discrete-time systems with positive control. Syst. Control Lett. 60(9), 690–698 (2011)Benvenuti, L.: On the reachable set for third-order linear discrete-time systems with positive control: the case of complex eigenvalues. Syst. Control Lett. 60(9), 1000–1008 (2011)Benzaouia, A., Hmamed, A., Tadeo, F.: Two-dimensional systems: from introduction to state of the art. In: Studies in Systems, Decision and Control (Vol. 28). Springer, Switzerland, (2016). https://doi.org/10.1007/978-3-319-20116-0Bru, R., Romero-Vivo, S. (eds.): Positive Systems: Theory and Applications. Lecture Notes in Control and Information Sciences, vol. 389. Springer, Berlin (2009)Bru, R., Bailo, E., Gelonch, J., Romero, S.: On the reachability index of positive 2-d systems. IEEE Trans. Circ. Syst. II: Express Brief 53(10), 997–1001 (2006)Bru, R., Coll, C., Romero, S., Sánchez, E.: Reachability indices of positive linear systems. Electron. J. Linear Algebra 11, 88–102 (2004)Bru, R., Romero-Vivó, S., Sánchez, E.: Reachability indices of periodic positive systems via positive shift-similarity. Linear Algebra Appl. 429, 1288–1301 (2008)Bru, R., Cacceta, L., Rumchev, V.G.: Monomial subdigraphs of reachable and controllable positive discrete-time systems. Int. J. Appl. Math. Comput. Sci. 15(1), 159–166 (2005)Bru, R., Romero, S., Sánchez, E.: Canonical forms of reachability and controllability of positive discrete-time control systems. Linear Algebra Appl. 310, 49–71 (2000)Cacace, F., Farina, L., Setola, R., Germani, A. (eds.): Positive Systems: Theory and Applications. Lecture Notes in Control and Information Sciences, vol. 471. Springer, Berlin (2017)Cantó, B., Coll, C., Sánchez, E.: On stability and reachability of perturbed positive systems. Adv. Differ. Equ. 2014(1), 296 (2014). https://doi.org/10.1186/1687-1847-2014-296Coll, C., Fullana, M., Sánchez, E.: Reachability and observability indices of a discrete-time periodic descriptor system. Appl. Math. Comput. 153, 485–496 (2004)Commault, C.: A simple graph theoretic characterization of reachability for positive linear systems. Syst. Control Lett. 52(3–4), 275–282 (2004)Commault, C.: On the reachability in any fixed time for positive continuous-time linear systems. Syst. Control Lett. 56(4), 272–276 (2007)Commault, C., Marchand, N. (eds.): Positive Systems: Theory and Applications. Lecture Notes in Control and Information Sciences, vol. 341. Springer, Berlin (2006)Coxson, P.G., Shapiro, H.: Positive reachability and controllability of positive systems. Linear Algebra Appl. 94, 35–53 (1987)Coxson, P.G., Larson, L.C., Schneider, H.: Monomial patterns in the sequence $${A}^kb$$. Linear Algebra Appl. 94, 89–101 (1987)De la Sen, M.: On the reachability and controllability of positive linear time-invariant dynamic systems with internal and external incommensurate point delays. Rocky Mt J Math 40(1), 177–207 (2010)Fanti, M.P., Maione, B., Turchiano, B.: Controllability of linear single-input positive discrete time systems. Int J Control 50, 2523–2542 (1989)Fanti, M.P., Maione, B., Turchiano, B.: Controllability of multi-input positive discrete time systems. Int J Control 51, 1295–1308 (1990)Farina, L., Rinaldi, S.: Positive Linear Systems: Theory and Applications. Pure and Applied Mathematics. Wiley, New York (2000)Fornasini, E., Marchesini, G.: State-Space realization of two-dimensional filters. IEEE Trans. Autom. Control AC–21(4), 484–491 (1976)Fornasini, E., Marchesini, G.: Doubly indexed dynamical systems. Math. Syst. Theory 12, 59–72 (1978)Fornasini, E., Valcher, M.E.: On the positive reachability of 2D positive systems. In: Farina, L., Benvenuti, L., De Santis, A. (eds.) Positive Systems. Lecture Notes in Control and Information Sciences, pp. 297–304. Springer, Berlin (2003)Fornasini, E., Valcher, M.E.: Controllability and reachability of 2-d positive systems: a graph theoretic approach. IEEE Trans. Circuits Syst. I Regul. Pap. 52(3), 576–585 (2005)Hrynlów, K., Markowski, K.A.: Experimental evaluation of upper bounds of reachability index for set of solutions of 2-D positive system. In: 17th International Carpathian Control Conference (ICCC), Tatranska Lomnica, pp. 248–252 (2016). https://doi.org/10.1109/CarpathianCC.2016.7501103Kaczorek, T.: Reachability and controllability of 2D positive linear systems with state feedback. Control Cybern. 29(1), 141–151 (2000)Kaczorek, T.: Positive 1D and 2D Systems. Springer, London (2002)Kaczorek, T.: Reachability and minimum energy control of positive 2D systems with delays. Control Cybern 34(2), 411–423 (2005)Kaczorek, T.: New reachability and observability tests for positive linear discrete-time systems. Bull. Polish Acad. Sci. Tech. Sci. 55(1), 19–21 (2007)Kaczorek, T.: Reachability of linear hybrid systems described by the general model. J. Arch. Control Sci. 20(2), 199–207 (2010)Kaczorek, T., Borawski, K.: Existence of reachable pairs (A, B) of discrete-time linear systems. In: Proceedings of 21st International Conference on Methods and Models in Automation and Robotics (MMAR). IEEE, pp. 702–707 (2016). https://doi.org/10.1109/MMAR.2016.7575222Kostova, S.P.: A PLDS model of pollution in connected water reservoirs. In: Benvenuti, L., De Santis, A., Farina, L. (eds.) Positive Systems. Lecture Notes in Control and Information Science, vol. 294, pp. 257–263. Springer, Berlin (2003)Marszalek, W.: Two-dimensional state space discrete models for hyperbolic partial differential equations. Appl. Math. Model. 8(1), 11–14 (1984)Markowski, K.A.: Determination reachability index space of positive two-dimensional linear system using digraph-based theory. In: 19th International Conference on System Theory, Control and Computing (ICSTCC), Cheile Gradistei, pp. 533–538 (2015). https://doi.org/10.1109/ICSTCC.2015.7321348Moysis, L., Mishra, V.: Existence of reachable and observable triples of linear discrete-time descriptor systems. Circ. Syst. Signal Process. 3, 1–13 (2018). https://doi.org/10.1007/s00034-018-0922-5Pereira, R., Rocha, P., Simões, R.: Characterizations of global reachability of 2D structured systems. Multidimens. Syst. Signal Process. 24, 1–14 (2011). https://doi.org/10.1007/s11045-011-0154-3Rumchev, V.G., James, D.J.G.: Reachability and controllability of time-variant discrete-time positive linear systems. Control Cybern. 33(1), 87–93 (2004)Rumchev, V., Chotijah, S.: The minimum energy problem for positive discrete-time linear systems with fixed final state. 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Traditional ecological knowledge supports ecosystem-based management in disturbed coastal marine social-ecological systems

A growing number of studies suggest a participatory ecosystem approach to support decision-making toward resilience and sustainability in social-ecological systems. Social-ecological resilience (SER) principles and practices are recommended to manage natural crises. However, it is necessary to broaden our understanding of SER on human-induced disturbances driven by economic development projects. In this paper we present the social-ecological system of Araçá Bay (Brazil), a small-scale fishery community that has experienced successive disturbances due to development projects since the 1930s. There was a lack of studies about the impacts of development projects in this bay. As part of a major project that aimed to build an ecosystem-based management plan for Araçá Bay through a participatory planning process, we focused on investigating fishers’ traditional ecological knowledge (TEK) to understand Araçá Bay’s small-scale fisheries social-ecological system. The objectives were to: (1) investigate fishers’ TEK regarding management practices and linked social mechanisms, human-induced disturbances and their consequences for the social-ecological system, ecosystem goods and services, and future threats; and (2) provide information based on TEK to the participatory planning process and analyze its contribution to Araçá Bay’s ecosystem-based management plan. Combined methods were used during 3 years of intense research-action (2014–2017): in-depth ethno-oceanographic interviews with expert fishers; monitoring Araçá Bay participatory meetings; and participant observation. Genuine local practices and social mechanisms from traditional culture were recorded, as well as TEK about 57 target fish species and methods to protect habitats and natural resources. Fishers also reported ecosystem disturbances and recovery processes. TEK was codified through SWOT analysis to assist the participatory planning process. Ecosystem services and threats based on TEK were brought to the participatory process, acknowledged by the participants, and incorporated into the management plan. TEK analysis proved to be an important methodology to provide historical environmental data regarding the impacts of development projects and support planning in disturbed ecosystems. In order to support coastal marine ecosystem-based management strategies toward SER and sustainability, researchers and practitioners should consider traditional territories in planning, recognize local practices and social mechanisms, and consider TEK on ecosystem goods and services and on historical human-induced disturbances

Morphology and dynamics of ice crystals and the effect of proteins

286 p.La tesis "Morfología y dinámica de los cristales de hielo y su efecto en las proteínas" se basa en una amplia gama de temas que abarcan el fundamento de la estructura del hielo (tanto su superficie como su morfología), la interacción de las proteínas con el hielo y las ciencias ambientales (formación de las nubes y la dinámica de los glaciares). El enfoque se centra en las interfaces hielo/vapor e hielo/agua.Mediante el microscopio electrónico de barrido ambiental (ESEM) a temperaturas inusualmente bajas, se ha logrado acceder a estudiar la morfología del hielo in-situ en diversas áreas del diagrama de fases (presión-temperatura). Además de reproducir las morfologías ya conocidas de cristales individuales e hielo poli-cristalino, se han observado formas ya conocidas de hielo, así como hielo poli-cristalino. Nuevas geometrías llamadas ¿pools¿, formas circulares de ¿m de diámetro, fueron encontradas en los límites del grano de la superficie del hielo poli-cristalino durante procesos de sublimación lento.Además, se estudiaron ocho soluciones diferentes de proteínas en condiciones de súper-enfriamiento mediante las técnicas de congelación de gota (drop freezing technique) y calorimetría diferencial de barrido (DSC). Únicamente, la (apo)ferritina y la ferritina han mostrado buenas características para la nucleación de hielo, es decir, la congelación bajo pequeño súper-enfriamiento (solo algunos grados debajo de 0 ºC), mientras que la mayoría de las soluciones de proteínas estudiadas se congelan por debajo de -15 ºC, como el agua pura.CIC NanoGUNE:nanoscience cooperative research center CFM: materials physics center ETH Zürich: Institute for Atmospheric and Climate Scienc

Earth resources: A continuing bibliography with indexes, issue 50

This bibliography lists 523 reports, articles and other documents introduced into the NASA scientific and technical information system between April 1 and June 30, 1986. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

NASA earth science and applications division: The program and plans for FY 1988-1989-1990

Described here are the Division's research goals, priorities and emphases for the next several years and an outline of longer term plans. Included are highlights of recent accomplishments, current activities in FY 1988, research emphases in FY 1989, and longer term future plans. Data and information systems, the Geodynamics Program, the Land Processes Program, the Oceanic Processes Program, the Atmospheric Dynamics and Radiation Program, the Atmospheric Chemistry Program, and space flight programs are among the topic covered

Climate Change, Carbon Capture, Storage and CO2 Mineralisation Technologies

This Special Issue delivered 16 scientific papers, with the aim of exploring the application of carbon capture and storage technologies for mitigating the effects of climate change. Special emphasis has been placed on mineral carbonation techniques that combine innovative applications to emerging problems and needs. The aim of this Special Issue is to contribute to improved knowledge of the ongoing research regarding climate change and CCS technological applications, focusing on carbon capture and storage practices. Climate change is a global issue that is interrelated with the energy and petroleum industry