951 research outputs found

    Light sensitive digital aspect sensor Patent

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    Light sensitive digital aspect sensor for attitude control of earth satellites or space probe

    Hierarchical control of intelligent machines applied to space station telerobots

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    A hierarchical architecture is described which supports space station telerobots in a variety of modes. The system is divided into three hierarchies: task decomposition, world model, and sensory processing. Goals at each level of the task decomposition hierarchy are divided both spatially and temporally into simpler commands for the next lower level. This decomposition is repeated until, at the lowest level, the drive signals to the robot actuators are generated. To accomplish its goals, task decomposition modules must often use information stored in the world model. The purpose of the sensory system is to update the world model as rapidly as possible to keep the model in registration with the physical world. The architecture of the entire control system hierarchy and how it can be applied to space telerobot applications are discussed

    NASREN: Standard reference model for telerobot control

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    A hierarchical architecture is described which supports space station telerobots in a variety of modes. The system is divided into three hierarchies: task decomposition, world model, and sensory processing. Goals at each level of the task dedomposition heirarchy are divided both spatially and temporally into simpler commands for the next lower level. This decomposition is repreated until, at the lowest level, the drive signals to the robot actuators are generated. To accomplish its goals, task decomposition modules must often use information stored it the world model. The purpose of the sensory system is to update the world model as rapidly as possible to keep the model in registration with the physical world. The architecture of the entire control system hierarch is described and how it can be applied to space telerobot applications

    Thermodynamics of a Trapped Bose-Fermi Mixture

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    By using the Hartree-Fock-Bogoliubov equations within the Popov approximation, we investigate the thermodynamic properties of a dilute binary Bose-Fermi mixture confined in an isotropic harmonic trap. For mixtures with an attractive Bose-Fermi interaction we find a sizable enhancement of the condensate fraction and of the critical temperature of Bose-Einstein condensation with respect to the predictions for a pure interacting Bose gas. Conversely, the influence of the repulsive Bose-Fermi interaction is less pronounced. The possible relevance of our results in current experiments on trapped 87Rb−40^{87}{\rm Rb}-^{40}{\rm K} mixtures is discussed.Comment: 5 pages + 4 figures; minor changes, final version to appear in Phys. Rev. A; the extension work on the finite-temperature low-lying excitations can be found in cond-mat/030763

    Pilot retrofit test of refrigerant R-134a for GDSCC

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    NASA has issued an interim policy requiring all of its Centers to eliminate consumption (purchase) of stratospheric ozone-depleting substances, including chlorofluorocarbons (CFC's), by 1995. Also, plans must be outlined for the eventual phase out of their usage. The greatest source of CFC consumption and usage at the Goldstone Deep Space Communications Complex is refrigerant R-12, which is used in many of the facility's air-conditioning systems. A pilot retrofit test shows that retrofitting R-12 air-conditioning systems with hydrofluorocarbon R-13a would be a workable means to comply with the R-12 portion of NASA's policy. Results indicate acceptable cost levels and nearly equivalent system performance

    Distributed control and navigation system for quadrotor UAVs in GPS-denied environments

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    The problem of developing distributed control and navigation system for quadrotor UAVs operating in GPS-denied environments is addressed in the paper. Cooperative navigation, marker detection and mapping task solved by a team of multiple unmanned aerial vehicles is chosen as demo example. Developed intelligent control system complies with on 4D\RCS reference model and its implementation is based on ROS framework. Custom implementation of EKF-based map building algorithm is used to solve marker detection and map building task.Comment: Camera-ready as submitted (and accepted) to the 7th IEEE International Conference Intelligent Systems IS'2014, September 24-26, 2014, Warsaw, Polan

    Mixtures of Bosonic and Fermionic Atoms in Optical Lattices

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    We discuss the theory of mixtures of Bosonic and Fermionic atoms in periodic potentials at zero temperature. We derive a general Bose--Fermi Hubbard Hamiltonian in a one--dimensional optical lattice with a superimposed harmonic trapping potential. We study the conditions for linear stability of the mixture and derive a mean field criterion for the onset of a Bosonic superfluid transition. We investigate the ground state properties of the mixture in the Gutzwiller formulation of mean field theory, and present numerical studies of finite systems. The Bosonic and Fermionic density distributions and the onset of quantum phase transitions to demixing and to a Bosonic Mott--insulator are studied as a function of the lattice potential strength. The existence is predicted of a disordered phase for mixtures loaded in very deep lattices. Such a disordered phase possessing many degenerate or quasi--degenerate ground states is related to a breaking of the mirror symmetry in the lattice.Comment: 11 pages, 8 figures; added discussions; conclusions and references expande

    Perceptual Context in Cognitive Hierarchies

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    Cognition does not only depend on bottom-up sensor feature abstraction, but also relies on contextual information being passed top-down. Context is higher level information that helps to predict belief states at lower levels. The main contribution of this paper is to provide a formalisation of perceptual context and its integration into a new process model for cognitive hierarchies. Several simple instantiations of a cognitive hierarchy are used to illustrate the role of context. Notably, we demonstrate the use context in a novel approach to visually track the pose of rigid objects with just a 2D camera

    Senior management model applied to micro, small and medium business

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    Siendo Colombia un país cuya economía se soporta en empresas de pequeña escala, donde las MIPYMES en conjunto representando el 90%, sector que genera el 73% de empleos y el 53% de la producción bruta en los diferentes sectores industriales, comerciales y de los servicios. No obstante de la importancia de este sector en la economía, muchas de ellas enfrentan una problemática que interrumpen su crecimiento y desarrollo. Este trabajo de investigación tiene como finalidad estructurar un modelo gerencial, el cual recoge aspectos importantes y valiosos a tener en cuenta por los dueños, gerentes y administradores; producto de identificar las debilidades que han impedido su crecimiento y desarrollo de manera efectiva en el campo empresarial moderno. Por lo anterior se analizó como debilidades más sentidas el desconocimiento y aplicación de teorías actuales en materia gerencial, que pueden actuar en miras de un mayor crecimiento y diversificación de sus ofertas de bienes y servicios, en este caso en el campo de los cosméticos; Soportado en los conocimientos adquiridos durante la Especialización en Alta Gerencia, se define desde un punto de vista particular pero responsable, los temas que deberían ser revisados por este tipo de empresas, para lograr la mejor comprensión y aplicación de temas tan importantes como Pensamiento Complejo, Análisis y Estudios de Competencias, Planeamiento Estratégico y Financiero, Gerencia de Mercado y Talento Humano.Colombia is a country whose economy is supported in small scale enterprises, where MIPYMES altogether representing 90%, sector that generates 73% of jobs and 53% of gross in the various sectors of industrial, commercial production and services. But the importance of this sector in the economy, many of them face problems that disrupt their growth and development. This research paper aims to structure a management model, which collects valuable and important aspects to be considered by owners and managers; product identify the weaknesses that have prevented its growth and development effectively in the modern business field. Therefore analyzed as most pressing weaknesses lack of knowledge and application of current theories in the management field, which may act in view of further growth and diversification of its offers of goods and services, in this case in the field of cosmetics; Supported the knowledge gained during the specialization in senior management, defined from a point of view responsible, but particular issues that should be reviewed by this kind of companies, to achieve better understanding and application of such important topics as complex thought, analysis and studies of competencies, strategic planning and financial, market and human resource managemen
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