2,473 research outputs found

    A geometrical approach to the motion planning problem for a submerged rigid body

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    The main focus of this paper is the motion planning problem for a deeply submerged rigid body. The equations of motion are formulated and presented by use of the framework of differential geometry and these equations incorporate external dissipative and restoring forces. We consider a kinematic reduction of the affine connection control system for the rigid body submerged in an ideal fluid, and present an extension of this reduction to the forced affine connection control system for the rigid body submerged in a viscous fluid. The motion planning strategy is based on kinematic motions; the integral curves of rank one kinematic reductions. This method is of particular interest to autonomous underwater vehicles which can not directly control all six degrees of freedom (such as torpedo shaped AUVs) or in case of actuator failure (i.e., under-actuated scenario). A practical example is included to illustrate our technique

    Geometry of Control-Affine Systems

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    Motivated by control-affine systems in optimal control theory, we introduce the notion of a point-affine distribution on a manifold X - i.e., an affine distribution F together with a distinguished vector field contained in F. We compute local invariants for point-affine distributions of constant type when dim(X)=n, rank(F)=n-1, and when dim(X)=3, rank(F)=1. Unlike linear distributions, which are characterized by integer-valued invariants - namely, the rank and growth vector - when dim(X)<=4, we find local invariants depending on arbitrary functions even for rank 1 point-affine distributions on manifolds of dimension 2

    Finsler geometry in low-dimensional control theory

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    Abstract. Following an introduction to control theory, we show how Finsler geometries occur in certain classes of control systems. 1

    Mutations on the N-terminal edge of the DELSEED loop in either the őĪ or ő≤ subunit of the mitochondrial F 1 -ATPase enhance ATP hydrolysis in the absence of the central ő≥ rotor

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    F1-ATPase is a rotary molecular machine with a subunit stoichiometry of őĪ3 ő≤3 ő≥1 őī1 őĶ1. It has a robust ATP-hydrolyzing activity due to effective cooperativity between the three catalytic sites. It is believed that the central ő≥ rotor dictates the

    Hong Kong and the implementation of the international Covenant on Civil and Political Rights

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    Law Library has videocassettes of this seminar.Proceedings of a seminar organised by the Centre for Comparative and Public Law, Faculty of Law, University of Hong Kong, 30 September 1995.Prepared for submission to the United Nations Human Rights Committee on the occasion of its consideration of the United Kingdom's fourth periodic report in respect of Hong Kong regarding the International Covenant on Civil and Political Rights.October 1995.published_or_final_versionSexual orientation and the law Brandon, Barrie Brandon, Barrie 53Freedom of expression Lau, Kevin Lau, Kevin 111The ICCPR and Vietnamese migrants in Hong Kong Harris, Paul Harris, Paul 99Sexual bias in the Hong Kong legal system: report of the Hong Kong council of women Jordan, Ann D. Jordan, Ann D. 81The failure of the Hong Kong government to implement the right to equality under the ICCPR: an analysis of the sex discrimination ordinance and the government's opposition to broader legislation Petersen, Carole J. Petersen, Carole J. 123Non-judicial domestic mechanisms in Hong Kong for the enforcement of civil and political rights Wu, Anna Wu, Anna 45Killing it softly? The Hong Kong courts and the slow demise of the Hong Kong Bill of Rights Byrnes, Andrew Byrnes, Andrew 31Reporting under the international covenant on civil and political rights Jayawickrama, Nihal Jayawickrama, Nihal 21Domestic mechanisms for implementing the international covenant on civil and political rights Bhagwati, P.N. Bhagwati, P.N. 13The international covenant on civil and political rights and the work of the human rights committee Mavrommatis, Andreas Mavrommatis, Andreas 3Contributor

    South Pacific Paleogene Climate

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    International Ocean Discovery Program (IODP) Expedition 378 was designed to recover the first comprehensive set of Paleogene sedimentary sections from a transect of sites strategically positioned in the South Pacific to reconstruct key changes in oceanic and atmospheric circulation. These sites would have provided an unparalleled opportunity to add crucial new data and geographic coverage to existing reconstructions of Paleogene climate. In addition to the ~15 month postponement of Expedition 378 and subsequent port changes resulting in a reduction of the number of primary sites, testing and evaluation of the R/V JOIDES Resolution derrick in the weeks preceding the expedition determined that it would not support deployment of drill strings in excess of 2 km. Because of this determination, only 1 of the originally approved 7 primary sites was drilled. Expedition 378 recovered the first continuously cored, multiple-hole Paleogene sedimentary section from the southern Campbell Plateau at Site U1553. This high‚Äďsouthern latitude site builds on the legacy of Deep Sea Drilling Project (DSDP) Site 277, a single, partially spot cored hole, providing a unique opportunity to refine and augment existing reconstructions of the past ~66 My of climate history. This also includes the discovery of a new siliciclastic unit that had never been drilled before. As the world‚Äôs largest ocean, the Pacific Ocean is intricately linked to major changes in the global climate system. Previous drilling in the low-latitude Pacific Ocean during Ocean Drilling Program (ODP) Legs 138 and 199 and Integrated Ocean Drilling Program Expeditions 320 and 321 provided new insights into climate and carbon system dynamics, productivity changes across the zone of divergence, time-dependent calcium carbonate dissolution, bio- and magnetostratigraphy, the location of the Intertropical Convergence Zone, and evolutionary patterns for times of climatic change and upheaval. Expedition 378 in the South Pacific Ocean uniquely complements this work with a high-latitude perspective, especially because appropriate high-latitude records are unobtainable in the Northern Hemisphere of the Pacific Ocean. Site U1553 and the entire corpus of shore-based investigations will significantly contribute to the challenges of the ‚ÄúClimate and Ocean Change: Reading the Past, Informing the Future‚ÄĚ theme of the IODP Science Plan (How does Earth‚Äôs climate system respond to elevated levels of atmospheric CO2? How resilient is the ocean to chemical perturbations?). Furthermore, Expedition 378 will provide material from the South Pacific Ocean in an area critical for high-latitude climate reconstructions spanning the Paleocene to late Oligocene

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at ‚ąös = 7 TeV with the ATLAS detector

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    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of ‚ąös = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentre‚ąíof‚ąímassframeisusedtosuppressthelargemulti‚ąíjetbackground.Thecross‚ąísectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques
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