Single network adaptive critic aided dynamic inversion for optimal regulation and command tracking with online adaptation for enhanced robustness

To combine the advantages of both stability and optimality-based designs, a single network adaptive critic (SNAC) aided nonlinear dynamic inversion approach is presented in this paper. Here, the gains of a dynamic inversion controller are selected in such a way that the resulting controller behaves very close to a pre-synthesized SNAC controller in the output regulation sense. Because SNAC is based on optimal control theory, it makes the dynamic inversion controller operate nearly optimal. More important, it retains the two major benefits of dynamic inversion, namely (i) a closed-form expression of the controller and (ii) easy scalability to command tracking applications without knowing the reference commands a priori. An extended architecture is also presented in this paper that adapts online to system modeling and inversion errors, as well as reduced control effectiveness, thereby leading to enhanced robustness. The strengths of this hybrid method of applying SNAC to optimize an nonlinear dynamic inversion controller is demonstrated by considering a benchmark problem in robotics, that is, a two-link robotic manipulator system. Copyright (C) 2013 John Wiley & Sons, Ltd.

Adaptive Flight-Control Design Using Neural-Network-Aided Optimal Nonlinear Dynamic Inversion

A neural-network-aided nonlinear dynamic inversion-based hybrid technique of model reference adaptive control flight-control system design is presented in this paper. Here, the gains of the nonlinear dynamic inversion-based flight-control system are dynamically selected in such a manner that the resulting controller mimics a single network, adaptive control, optimal nonlinear controller for state regulation. Traditional model reference adaptive control methods use a linearized reference model, and the presented control design method employs a nonlinear reference model to compute the nonlinear dynamic inversion gains. This innovation of designing the gain elements after synthesizing the single network adaptive controller maintains the advantages that an optimal controller offers, yet it retains a simple closed-form control expression in state feedback form, which can easily be modified for tracking problems without demanding any a priori knowledge of the reference signals. The strength of the technique is demonstrated by considering the longitudinal motion of a nonlinear aircraft system. An extended single network adaptive control/nonlinear dynamic inversion adaptive control design architecture is also presented, which adapts online to three failure conditions, namely, a thrust failure, an elevator failure, and an inaccuracy in the estimation of C-M alpha. Simulation results demonstrate that the presented adaptive flight controller generates a near-optimal response when compared to a traditional nonlinear dynamic inversion controller.

An estimate of the number of tropical tree species

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between similar to 40,000 and similar to 53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of similar to 19,000-25,000 tree species. Continental Africa is relatively depauperate with a minimum of similar to 4,500-6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa.

El ciclo artúrico en el cine; mito y epos en Excalibur, de John Boorman

Integran este número de la revista ponencias presentadas en Studia Hispanica Medievalia VIII: Actas de las IX Jornadas Internacionales de Literatura Española Medieval, 2008, y de Homenaje al Quinto Centenario de Amadis de Gaula.

Creemos porque amamos : la estructura interna del acto de fe en John Henry Newman

El autor nos introduce en la cuestión de los motivos racionales de la fe. Las operaciones llevadas a cabo por la inteligencia y la voluntad en el acto de creer, constituyen el fundamento por el cual la Verdad revelada entabla históricamente el diálogo con el hombre. El tema se halla en el centro de la experiencia religiosa y de la reflexión teológica de Newman, y ha significado un aporte indiscutible a la teología contemporánea.

Mi colaboración con John Finnis

Advertí por primera vez la existencia de John Finnis cuando me envió una nota de felicitación en ocasión de la publicación de mi libro de 1970, Abortion: The Myths, the Realities, and the Arguments. Uno de los capítulos del libro fue el fruto de una extensa investigación en bibliotecas jurídicas, y me sentí tremendamente satisfecho al recibir la aprobación de un catedrático de Oxford y profesor de Derecho. John y yo trabajamos juntos por primera vez desde el 25 de abril al 1º de marzo de 1974, en un hotel de Roma, en cuatro capítulos sobre ética cristiana para el libro The Teaching of Christ: A Catholic Catechism for Adults, el cual fue editado por Ronald Lawler, Donald Wuerl y Thomas Comerford Lawler –un libro que fue traducido en trece idiomas y ha atravesado cinco ediciones, al igual que algunas versiones simplificadas para gente joven...

John Locke : las posesiones o los derechos políticos como garantía de la libertad

Este artículo busca reflexionar sobre las garantías que el contrato social de John Locke ofrece a la libertad. Así, apartándose de la corriente de interpretación dominante, se intenta realizar una aproximación hermenéutica a su obra que de cuenta del campo semántico en el cual se desarrolla. De esta manera, aflorará la propia voz del autor permitiendo dilucidar cuál es el contenido y el alcance de la libertad en el contrato social lockeano.

Antiguo Oriente: Cuadernos del Centro de Estudios de Historia del Antiguo Oriente, 2008, n° 6 (número completo)

Sumario -- The pottery of Edom: A Correction / Israel Finkelstein & Lily Singer-Avitz -- The Jezirah Burnished Ware / Stefano Valentini -- The Cordage from Berenike (1994-2000): The Statics / André J. Veldmeijer -- A Reevaluation of the Use of !bz and bhy in Elephantine / Alejandro F. Botta -- Four Ur III Administrative Tablets in the Possesion of Professor Francis Carroll, University of Manitoba / John Nielsen -- Una actualización de la Cronología Baja: arqueología, historia y Biblia / Israel Finkelstein -- The Alleged “Anchor Point” of 732 BC for the Destrction of Hazor V / Peter James -- The “Wicked Priest” in Egyptology and Amarna Studies: A Reconsideration / Samuel Jackson -- Violencia fenicia en el Mediterráneo Oriental / Jordi Vidal -- Reportes de Excavación -- The Leatherwork from Deir el-Bachit: Preliminary Report / André J. Veldmeijer -- Reseñas bibliográficas -- Política editorial e instrucciones para los colaboradores -- Direcciones para envío de artículos y reseñas bibliográficas -- Colaboraciones en numeros anteriores

La “experiencia religiosa” forjadora de un lenguaje teológico significativo en John Henry Newman

El autor plantea la cuestión de lo significativo del lenguaje teológico a partir del concepto de experiencia en el pensamiento del cardenal Newman. Su itinerario de fe y conversión, enraizado en un diálogo personal con Dios, le ha dado tanto a su teología como a su predicación, un atractivo que trasciende su época y que puede servir de estímulo actualmente en la comunicación teológica.

Sobre ciencia práctica y prudentia : aproximaciones desde las ideas de John Finnis

Resumen: En el presente trabajo, el autor ensaya una presentación de las contribuciones de John Finnis a los temas de la ciencia práctica y la prudentia. Respecto del primero, destaca el carácter analógico del concepto de ciencia y las particularidades de su aplicación al campo del saber práctico. Con referencia a la segunda, apunta su relevancia en el esquema clásico del pensamiento práctico, en especial en referencia a la determinación de los objetos de las virtudes y al papel de los absolutos morales en el razonamiento práctico-moral.

En las raíces ideológicas de Montoneros : John William Cooke lee a Gramsci en Cuba

Desde 1945 la izquierda argentina no pudo resolver el enigma planteado por el hecho de que la clase obrera era peronista. Varios intentos teóricos fracasaron antes de que John William Cooke hiciera el suyo a mediados de los años sesenta. Influenciado por Gramsci, consideró que la clase obrera es una categoría histórica, por lo que el peronismo era la experiencia histórica de la clase obrera argentina y, como tal, revolucionario. Neutralizó el papel político de Perón convirtiéndolo en el símbolo de la identidad peronista. Por esto, la teoría de Cooke fue clave para que guerrilleros de izquierda se declararan peronistas sin que les importaran las opiniones e intenciones políticas de Perón. Las limitaciones de esa teoría quedaron expuestas cuando el general regresó a la Argentina y fue electo presidente por tercera vez.

Broughton Archipelago Clam Terrace Survey : final report

During a 1995 aerial video survey of the coastline of Johnstone Strait, an unusual shoreline feature was noted and termed “clam terraces” (inset) because of the terrace-type morphology and the apparent association with high clam productivity on the sandflats. Typical alongshore lengths of the terrace ridges are 20-50m, and across-shore widths are typically 20-40m. An area with an especially high density of clam terraces was noted in the Broughton Archipelago, between Broughton and Gilford Islands of southeastern Queen Charlotte Strait. Clam terraces in this area were inventoried from the aerial video imagery to quantify their distribution. The terraces accounted for over 14 km of shoreline and 365 clam terraces were documented. A three-day field survey by a coastal geomorphologist, archeologist and marine biologist was conducted to document the features and determine their origin. Nine clam terraces were surveyed. The field observations confirmed that: the ridges are comprised of boulder/cobblesized material, ridge crests are typically in the range of 1-1.5m above chart datum, sandflats are comprised almost entirely of shell fragments (barnacles and clams) and sandflats have very high shellfish production. There are an abundance of shell middens in the area (over 175) suggesting that the shellfish associated with the terraces were an important food source of aboriginal peoples. The origin of the ridges is unknown; they appear to be a relict feature in that they are not actively being modified by present-day processes. The ridges may be a relict sea-ice feature, although the mechanics of ridge formation is uncertain. Sand accumulates behind the ridge because the supply rate of the shell fragments exceeds the dispersal rate in these low energy environments. The high density areas of clam terraces correspond to high density areas of shell middens, and it is probable that the clam terraces were subjected to some degree of modification by aboriginal shellfish gatherers over the thousands of years of occupation in the region. (Document contains 39 pages)

Proceedings of the 1998 Science Board Symposium on The Impacts of the 1997/98 El Niño Event on the North Pacific Ocean and Its Marginal Seas

Preface [pdf, 0.01 Mb] James J. O'Brien The big picture - The ENSO of 1997-98 [pdf, 0.01 Mb] James E. Overland, Nicholas A. Bond & Jennifer Miletta Adams Atmospheric anomalies in 1997: Links to ENSO? [pdf, 0.54 Mb] Vladimir I. Ponomarev, Olga Trusenkova, Serge Trousenkov, Dmitry Kaplunenko, Elena Ustinova & Antonina Polyakova The ENSO signal in the northwest Pacific [pdf, 0.47 Mb] Robert L. Smith, A. Huyer, P.M. Kosro & J.A. Barth Observations of El Niño off Oregon: July 1997 to present (October 1998) [pdf, 1.31 Mb] Patrica A. Wheeler & Jon Hill Biological effects of the 1997-1998 El Niño event off Oregon: Nutrient and chlorophyll distributions [pdf, 1.13 Mb] William T. Peterson Hydrography and zooplankton off the central Oregon coast during the 1997-1998 El Niño event [pdf, 0.26 Mb] William Crawford, Josef Cherniawsky, Michael Foreman & Peter Chandler El Niño sea level signal along the west coast of Canada [pdf, 1.25 Mb] Howard J. Freeland & Rick Thomson The El Niño signal along the west coast of Canada - temperature, salinity and velocity [pdf, 0.49 Mb] Frank A. Whitney, David L. Mackas, David W. Welch & Marie Robert Impact of the 1990s El Niños on nutrient supply and productivity of Gulf of Alaska waters [pdf, 0.06 Mb] Craig McNeil, David Farmer & Mark Trevorrow Dissolved gas measurements at Stn. P4 during the 97-98 El Niño [pdf, 0.13 Mb] Kristen L.D. Milligan, Colin D. Levings & Robert E. DeWreede Data compilation and preliminary time series analysis of abundance of a dominant intertidal kelp species in relation to the 1997/1998 El Niño event [pdf, 0.05 Mb] S.M. McKinnell, C.C. Wood, M. Lapointe, J.C. Woodey, K.E. Kostow, J. Nelson & K.D. Hyatt Reviewing the evidence that adult sockeye salmon strayed from the Fraser River and spawned in other rivers in 1997 [pdf,0.03 Mb] G.A. McFarlane & R.J. Beamish Sardines return to British Columbia waters [pdf, 0.34 Mb] Ken H. Morgan Impact of the 1997/98 El Niño on seabirds of the northeast Pacific [pdf, 0.06 Mb] Thomas C. Royer & Thomas Weingartner Coastal hydrographic responses in the northern Gulf of Alaska to the 1997-98 ENSO event [pdf, 0.76 Mb] John F. Piatt, Gary Drew, Thomas Van Pelt, Alisa Abookire, April Nielsen, Mike Shultz & Alexander Kitaysky Biological effects of the 1997/98 ENSO in Cook Inlet, Alaska [pdf, 0.22 Mb] H.J. Niebauer The 1997-98 El Niño in the Bering Sea as compared with previous ENSO events and the "regime shift" of the late 1970s [pdf, 0.10 Mb] A.S. Krovnin, G.P. Nanyushin, M.Yu. Kruzhalov, G.V. Khen, M.A. Bogdanov, E.I. Ustinova, V.V. Maslennikov, A.M. Orlov, B.N. Kotenev, V.V. Bulanov & G.P. Muriy The state of the Far East seas during the 1997/98 El Niño event [pdf, 0.15 Mb] Stacy Smith & Susan Henrichs Phytoplankton collected by a time-series sediment trap deployed in the southeast Bering Sea during 1997 [pdf, 0.21 Mb] Cynthia T. Tynan Redistributions of cetaceans in the southeast Bering Sea relative to anomalous oceanographic conditions during the 1997 El Niño [pdf, 0.02 Mb] Akihiko Yatsu, Junta Mori, Hiroyuki Tanaka, Tomowo Watanabe, Kazuya Nagasawa, Yikimasa Ishida, Toshimi Meguro, Yoshihiko Kamei & Yasunori Sakurai Stock abundance and size compositions of the neon flying squid in the central North Pacific Ocean during 1979-1998 [pdf, 0.11 Mb] O.B. Feschenko A new point of view concerning the El Niño mechanism [pdf, 0.01 Mb] Nathan Mantua 97/98 Ocean climate variability in the northeast Pacific: How much blame does El Niño deserve? [pdf, 0.01 Mb] Vadim P. Pavlychev Sharp changes of hydrometeorological conditions in the northwestern Pacific during the 1997/1998 El Niño event [pdf, 0.01 Mb] Jingyi Wang Predictability and forecast verification of El Niño events [pdf, 0.01 Mb] (Document contains 110 pages)

O Federalista

Coletânea de artigos, a maior parte deles, cinquenta e um, escritos por Alexander Hamilton, quatorze, por James Madison, cinco, por John Jay, e outros doze compostos por Hamilton e Madison. Foram primeiramente publicados em um jornal de Nova York. Em 1787, foi publicada em livro. No Brasil, a primeira edição em português é de 1840.