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Sample records for automatic multiple-zone rigid-body

  1. SYMBOD - A computer program for the automatic generation of symbolic equations of motion for systems of hinge-connected rigid bodies

    NASA Technical Reports Server (NTRS)

    Macala, G. A.

    1983-01-01

    A computer program is described that can automatically generate symbolic equations of motion for systems of hinge-connected rigid bodies with tree topologies. The dynamical formulation underlying the program is outlined, and examples are given to show how a symbolic language is used to code the formulation. The program is applied to generate the equations of motion for a four-body model of the Galileo spacecraft. The resulting equations are shown to be a factor of three faster in execution time than conventional numerical subroutines.

  2. Rigid body dynamics on the Poisson torus

    NASA Astrophysics Data System (ADS)

    Richter, Peter H.

    2008-11-01

    The theory of rigid body motion with emphasis on the modifications introduced by a Cardan suspension is outlined. The configuration space is no longer SO(3) but a 3-torus; the equivalent of the Poisson sphere, after separation of an angular variable, is a Poisson torus. Iso-energy surfaces and their bifurcations are discussed. A universal Poincaré section method is proposed.

  3. Quantum mechanics of a generalised rigid body

    NASA Astrophysics Data System (ADS)

    Gripaios, Ben; Sutherland, Dave

    2016-05-01

    We consider the quantum version of Arnold’s generalisation of a rigid body in classical mechanics. Thus, we quantise the motion on an arbitrary Lie group manifold of a particle whose classical trajectories correspond to the geodesics of any one-sided-invariant metric. We show how the derivation of the spectrum of energy eigenstates can be simplified by making use of automorphisms of the Lie algebra and (for groups of type I) by methods of harmonic analysis. We show how the method can be extended to cosets, generalising the linear rigid rotor. As examples, we consider all connected and simply connected Lie groups up to dimension 3. This includes the universal cover of the archetypical rigid body, along with a number of new exactly solvable models. We also discuss a possible application to the topical problem of quantising a perfect fluid.

  4. Does a rigid body limit maneuverability?

    PubMed

    Walker, J A

    2000-11-01

    Whether a rigid body limits maneuverability depends on how maneuverability is defined. By the current definition, the minimum radius of the turn, a rigid-bodied, spotted boxfish Ostracion meleagris approaches maximum maneuverability, i.e. it can spin around with minimum turning radii near zero. The radius of the minimum space required to turn is an alternative measure of maneuverability. By this definition, O. meleagris is not very maneuverable. The observed space required by O. meleagris to turn is slightly greater than its theoretical minimum but much greater than that of highly flexible fish. Agility, the rate of turning, is related to maneuverability. The median- and pectoral-fin-powered turns of O. meleagris are slow relative to the body- and caudal-fin-powered turns of more flexible fish.

  5. New Langevin and gradient thermostats for rigid body dynamics

    NASA Astrophysics Data System (ADS)

    Davidchack, R. L.; Ouldridge, T. E.; Tretyakov, M. V.

    2015-04-01

    We introduce two new thermostats, one of Langevin type and one of gradient (Brownian) type, for rigid body dynamics. We formulate rotation using the quaternion representation of angular coordinates; both thermostats preserve the unit length of quaternions. The Langevin thermostat also ensures that the conjugate angular momenta stay within the tangent space of the quaternion coordinates, as required by the Hamiltonian dynamics of rigid bodies. We have constructed three geometric numerical integrators for the Langevin thermostat and one for the gradient thermostat. The numerical integrators reflect key properties of the thermostats themselves. Namely, they all preserve the unit length of quaternions, automatically, without the need of a projection onto the unit sphere. The Langevin integrators also ensure that the angular momenta remain within the tangent space of the quaternion coordinates. The Langevin integrators are quasi-symplectic and of weak order two. The numerical method for the gradient thermostat is of weak order one. Its construction exploits ideas of Lie-group type integrators for differential equations on manifolds. We numerically compare the discretization errors of the Langevin integrators, as well as the efficiency of the gradient integrator compared to the Langevin ones when used in the simulation of rigid TIP4P water model with smoothly truncated electrostatic interactions. We observe that the gradient integrator is computationally less efficient than the Langevin integrators. We also compare the relative accuracy of the Langevin integrators in evaluating various static quantities and give recommendations as to the choice of an appropriate integrator.

  6. New Langevin and gradient thermostats for rigid body dynamics.

    PubMed

    Davidchack, R L; Ouldridge, T E; Tretyakov, M V

    2015-04-14

    We introduce two new thermostats, one of Langevin type and one of gradient (Brownian) type, for rigid body dynamics. We formulate rotation using the quaternion representation of angular coordinates; both thermostats preserve the unit length of quaternions. The Langevin thermostat also ensures that the conjugate angular momenta stay within the tangent space of the quaternion coordinates, as required by the Hamiltonian dynamics of rigid bodies. We have constructed three geometric numerical integrators for the Langevin thermostat and one for the gradient thermostat. The numerical integrators reflect key properties of the thermostats themselves. Namely, they all preserve the unit length of quaternions, automatically, without the need of a projection onto the unit sphere. The Langevin integrators also ensure that the angular momenta remain within the tangent space of the quaternion coordinates. The Langevin integrators are quasi-symplectic and of weak order two. The numerical method for the gradient thermostat is of weak order one. Its construction exploits ideas of Lie-group type integrators for differential equations on manifolds. We numerically compare the discretization errors of the Langevin integrators, as well as the efficiency of the gradient integrator compared to the Langevin ones when used in the simulation of rigid TIP4P water model with smoothly truncated electrostatic interactions. We observe that the gradient integrator is computationally less efficient than the Langevin integrators. We also compare the relative accuracy of the Langevin integrators in evaluating various static quantities and give recommendations as to the choice of an appropriate integrator. PMID:25877569

  7. New Langevin and gradient thermostats for rigid body dynamics.

    PubMed

    Davidchack, R L; Ouldridge, T E; Tretyakov, M V

    2015-04-14

    We introduce two new thermostats, one of Langevin type and one of gradient (Brownian) type, for rigid body dynamics. We formulate rotation using the quaternion representation of angular coordinates; both thermostats preserve the unit length of quaternions. The Langevin thermostat also ensures that the conjugate angular momenta stay within the tangent space of the quaternion coordinates, as required by the Hamiltonian dynamics of rigid bodies. We have constructed three geometric numerical integrators for the Langevin thermostat and one for the gradient thermostat. The numerical integrators reflect key properties of the thermostats themselves. Namely, they all preserve the unit length of quaternions, automatically, without the need of a projection onto the unit sphere. The Langevin integrators also ensure that the angular momenta remain within the tangent space of the quaternion coordinates. The Langevin integrators are quasi-symplectic and of weak order two. The numerical method for the gradient thermostat is of weak order one. Its construction exploits ideas of Lie-group type integrators for differential equations on manifolds. We numerically compare the discretization errors of the Langevin integrators, as well as the efficiency of the gradient integrator compared to the Langevin ones when used in the simulation of rigid TIP4P water model with smoothly truncated electrostatic interactions. We observe that the gradient integrator is computationally less efficient than the Langevin integrators. We also compare the relative accuracy of the Langevin integrators in evaluating various static quantities and give recommendations as to the choice of an appropriate integrator.

  8. Fast collision detection for fracturing rigid bodies.

    PubMed

    Glondu, Loeiz; Schvartzman, Sara C; Marchal, Maud; Dumont, Georges; Otaduy, Miguel A

    2014-01-01

    In complex scenes with many objects, collision detection plays a key role in the simulation performance. This is particularly true in fracture simulation for two main reasons. One is that fracture fragments tend to exhibit very intensive contact, and the other is that collision detection data structures for new fragments need to be computed on the fly. In this paper, we present novel collision detection algorithms and data structures for real-time simulation of fracturing rigid bodies. We build on a combination of well-known efficient data structures, namely, distance fields and sphere trees, making our algorithm easy to integrate on existing simulation engines. We propose novel methods to construct these data structures, such that they can be efficiently updated upon fracture events and integrated in a simple yet effective self-adapting contact selection algorithm. Altogether, we drastically reduce the cost of both collision detection and collision response. We have evaluated our global solution for collision detection on challenging scenarios, achieving high frame rates suited for hard real-time applications such as video games or haptics. Our solution opens promising perspectives for complex fracture simulations involving many dynamically created rigid objects. PMID:24201324

  9. Fast Collision Detection for Fracturing Rigid Bodies.

    PubMed

    Glondu, Loeiz; Schvartzman, Sara C; Marchal, Maud; Dumont, Georges; Otaduy, Miguel A

    2013-07-01

    In complex scenes with many objects, collision detection plays a key role in the simulation performance. This is particularly true in fracture simulation for two main reasons. One is that fracture fragments tend to exhibit very intensive contact, and the other is that collision detection data structures for new fragments need to be computed on the fly. In this paper, we present novel collision detection algorithms and data structures for real-time simulation of fracturing rigid bodies. We build on a combination of well-known efficient data structures, namely distance fields and sphere trees, making our algorithm easy to integrate on existing simulation engines. We propose novel methods to construct these data structures, such that they can be efficiently updated upon fracture events and integrated in a simple yet effective self-adapting contact selection algorithm. Altogether, we drastically reduce the cost of both collision detection and collision response. We have evaluated our global solution for collision detection on challenging scenarios, achieving high frame rates suited for hard real-time applications such as video games or haptics. Our solution opens promising perspectives for complex fracture simulations involving many dynamically created rigid objects. PMID:23836702

  10. Rigid Body Motion in Stereo 3D Simulation

    ERIC Educational Resources Information Center

    Zabunov, Svetoslav

    2010-01-01

    This paper addresses the difficulties experienced by first-grade students studying rigid body motion at Sofia University. Most quantities describing the rigid body are in relations that the students find hard to visualize and understand. They also lose the notion of cause-result relations between vector quantities, such as the relation between…

  11. Rapid determination of RMSDs corresponding to macromolecular rigid body motions.

    PubMed

    Popov, Petr; Grudinin, Sergei

    2014-05-01

    Finding the root mean sum of squared deviations (RMSDs) between two coordinate vectors that correspond to the rigid body motion of a macromolecule is an important problem in structural bioinformatics, computational chemistry, and molecular modeling. Standard algorithms compute the RMSD with time proportional to the number of atoms in the molecule. Here, we present RigidRMSD, a new algorithm that determines a set of RMSDs corresponding to a set of rigid body motions of a macromolecule in constant time with respect to the number of atoms in the molecule. Our algorithm is particularly useful for rigid body modeling applications, such as rigid body docking, and also for high-throughput analysis of rigid body modeling and simulation results. We also introduce a constant-time rotation RMSD as a similarity measure for rigid molecules. A C++ implementation of our algorithm is available at http://nano-d.inrialpes.fr/software/RigidRMSD. PMID:24615729

  12. Brownian dynamics of confined rigid bodies.

    PubMed

    Delong, Steven; Balboa Usabiaga, Florencio; Donev, Aleksandar

    2015-10-14

    We introduce numerical methods for simulating the diffusive motion of rigid bodies of arbitrary shape immersed in a viscous fluid. We parameterize the orientation of the bodies using normalized quaternions, which are numerically robust, space efficient, and easy to accumulate. We construct a system of overdamped Langevin equations in the quaternion representation that accounts for hydrodynamic effects, preserves the unit-norm constraint on the quaternion, and is time reversible with respect to the Gibbs-Boltzmann distribution at equilibrium. We introduce two schemes for temporal integration of the overdamped Langevin equations of motion, one based on the Fixman midpoint method and the other based on a random finite difference approach, both of which ensure that the correct stochastic drift term is captured in a computationally efficient way. We study several examples of rigid colloidal particles diffusing near a no-slip boundary and demonstrate the importance of the choice of tracking point on the measured translational mean square displacement (MSD). We examine the average short-time as well as the long-time quasi-two-dimensional diffusion coefficient of a rigid particle sedimented near a bottom wall due to gravity. For several particle shapes, we find a choice of tracking point that makes the MSD essentially linear with time, allowing us to estimate the long-time diffusion coefficient efficiently using a Monte Carlo method. However, in general, such a special choice of tracking point does not exist, and numerical techniques for simulating long trajectories, such as the ones we introduce here, are necessary to study diffusion on long time scales. PMID:26472363

  13. Brownian dynamics of confined rigid bodies

    NASA Astrophysics Data System (ADS)

    Delong, Steven; Balboa Usabiaga, Florencio; Donev, Aleksandar

    2015-10-01

    We introduce numerical methods for simulating the diffusive motion of rigid bodies of arbitrary shape immersed in a viscous fluid. We parameterize the orientation of the bodies using normalized quaternions, which are numerically robust, space efficient, and easy to accumulate. We construct a system of overdamped Langevin equations in the quaternion representation that accounts for hydrodynamic effects, preserves the unit-norm constraint on the quaternion, and is time reversible with respect to the Gibbs-Boltzmann distribution at equilibrium. We introduce two schemes for temporal integration of the overdamped Langevin equations of motion, one based on the Fixman midpoint method and the other based on a random finite difference approach, both of which ensure that the correct stochastic drift term is captured in a computationally efficient way. We study several examples of rigid colloidal particles diffusing near a no-slip boundary and demonstrate the importance of the choice of tracking point on the measured translational mean square displacement (MSD). We examine the average short-time as well as the long-time quasi-two-dimensional diffusion coefficient of a rigid particle sedimented near a bottom wall due to gravity. For several particle shapes, we find a choice of tracking point that makes the MSD essentially linear with time, allowing us to estimate the long-time diffusion coefficient efficiently using a Monte Carlo method. However, in general, such a special choice of tracking point does not exist, and numerical techniques for simulating long trajectories, such as the ones we introduce here, are necessary to study diffusion on long time scales.

  14. Brownian dynamics of confined rigid bodies

    SciTech Connect

    Delong, Steven; Balboa Usabiaga, Florencio; Donev, Aleksandar

    2015-10-14

    We introduce numerical methods for simulating the diffusive motion of rigid bodies of arbitrary shape immersed in a viscous fluid. We parameterize the orientation of the bodies using normalized quaternions, which are numerically robust, space efficient, and easy to accumulate. We construct a system of overdamped Langevin equations in the quaternion representation that accounts for hydrodynamic effects, preserves the unit-norm constraint on the quaternion, and is time reversible with respect to the Gibbs-Boltzmann distribution at equilibrium. We introduce two schemes for temporal integration of the overdamped Langevin equations of motion, one based on the Fixman midpoint method and the other based on a random finite difference approach, both of which ensure that the correct stochastic drift term is captured in a computationally efficient way. We study several examples of rigid colloidal particles diffusing near a no-slip boundary and demonstrate the importance of the choice of tracking point on the measured translational mean square displacement (MSD). We examine the average short-time as well as the long-time quasi-two-dimensional diffusion coefficient of a rigid particle sedimented near a bottom wall due to gravity. For several particle shapes, we find a choice of tracking point that makes the MSD essentially linear with time, allowing us to estimate the long-time diffusion coefficient efficiently using a Monte Carlo method. However, in general, such a special choice of tracking point does not exist, and numerical techniques for simulating long trajectories, such as the ones we introduce here, are necessary to study diffusion on long time scales.

  15. New generalizations of the integrable problems in rigid body dynamics

    NASA Astrophysics Data System (ADS)

    Yehia, H. M.

    1997-10-01

    We consider the general problem of motion of a rigid body about a fixed point under the action of an axisymmetric combination of potential and gyroscopic forces. We introduce six cases of this problem which are completely integrable for arbitrary initial conditions. The new cases generalize by several parameters all, but one, of the known results in the subject of rigid body dynamics. Namely, we generalize all the results due to Euler, Lagrange, Clebsch, Kovalevskaya, Brun and Lyapunov and also their subsequent generalizations by Rubanovsky and the present author.

  16. Effect of Base Shape on Damping of Rocking of Rigid Body

    NASA Astrophysics Data System (ADS)

    Imanishi, Nozomu; Inoue, Yoshio; Shibata, Kyoko; Sato, Kazutomo; Yamasaki, Yoshihiko

    Effect of base shape on damping characteristics of rocking of rigid body is presented. We pay attention to the fact that free vibration amplitude of rigid body decreases rapidly without dampers or damping materials. We consider rocking of rigid body is very attractive as a low cost dynamic vibration absorber. At first, damping characteristics of rocking of typical rigid body with flat base shape is discussed theoretically. Next, we propose new type rigid body which base shape is polygon in order to design damping characteristics of rigid body in wide range. Theoretical method to calculate damping characteristics of rigid body is derived. Experiment of free vibration of the rigid body is carried out and the calculated results of the proposed method agree well with the experimental results. By calculating damping ratio of proposed rigid body using derived equations, it can be seen polygon base shape is very useful to design damping characteristics of rigid body.

  17. Knowledge-In-Action: An Example with Rigid Body Motion

    ERIC Educational Resources Information Center

    Da Costa, Sayonara Salvador Cabral; Moreira, Marco Antonio

    2005-01-01

    This paper reports the analysis of the resolution of a paper-and-pencil problem, by eight undergraduate students majoring in engineering (six) and physics (two) at the Pontifcia Universidade Catlica do Rio Grande do Sul, in Porto Alegre, Brazil. The problem concerns kinetics of a rigid body, and the analysis was done in the light of Johnson-Lairds…

  18. Stability characterizations of fixtured rigid bodies with Coulomb friction

    SciTech Connect

    PANG,J.S.; TRINKLE,JEFFREY C.

    2000-02-15

    This paper formally introduces several stability characterizations of fixtured three-dimensional rigid bodies initially at rest and in unilateral contact with Coulomb friction. These characterizations, weak stability and strong stability, arise naturally from the dynamic model of the system, formulated as a complementarity problem. Using the tools of complementarity theory, these characterizations are studied in detail to understand their properties and to develop techniques to identify the stability classifications of general systems subjected to known external loads.

  19. Stabilization of the permanent rotations of a rigid body

    NASA Astrophysics Data System (ADS)

    Biiarov, T.; Krementulo, V. V.; Tazhekov, A.

    1991-08-01

    The problem of stabilization of the equilibrium and permanent rotations of a heavy rigid body with a fixed point is solved in the classical cases of Euler, Lagrange, and Kovalevskaya using methods of analytical control theory. In the above cases, the control moments obtained in explicit form provide for the asymptotic stability of the permanent rotation on the whole. The control moments are selected in the form of linear functions with respect to perturbations.

  20. The free rigid body dynamics: Generalized versus classic

    NASA Astrophysics Data System (ADS)

    Tudoran, Rǎzvan M.

    2013-07-01

    In this paper we analyze some normal forms of a general quadratic Hamiltonian system defined on the dual of the Lie algebra {o}(K) of real K-skew-symmetric matrices, where K is an arbitrary 3×3 real symmetric matrix. A consequence of the main results is that any first-order autonomous three-dimensional differential equation possessing two independent quadratic constants of motion, which admit a positive/negative definite linear combination, is affinely equivalent to the classical "relaxed" free rigid body dynamics with linear control parameters.

  1. Plane stress problems using hysteretic rigid body spring network models

    NASA Astrophysics Data System (ADS)

    Christos, Sofianos D.; Vlasis, Koumousis K.

    2016-08-01

    In this work, a discrete numerical scheme is presented capable of modeling the hysteretic behavior of 2D structures. Rigid Body Spring Network (RBSN) models that were first proposed by Kawai (Nucl Eng Des 48(1):29-207, 1978) are extended to account for hysteretic elastoplastic behavior. Discretization is based on Voronoi tessellation, as proposed specifically for RBSN models to ensure uniformity. As a result, the structure is discretized into convex polygons that form the discrete rigid bodies of the model. These are connected with three zero length, i.e., single-node springs in the middle of their common facets. The springs follow the smooth hysteretic Bouc-Wen model which efficiently incorporates classical plasticity with no direct reference to a yield surface. Numerical results for both static and dynamic loadings are presented, which validate the proposed simplified spring-mass formulation. In addition, they verify the model's applicability on determining primarily the displacement field and plastic zones compared to the standard elastoplastic finite element method.

  2. Computational Fluid Dynamics Demonstration of Rigid Bodies in Motion

    NASA Technical Reports Server (NTRS)

    Camarena, Ernesto; Vu, Bruce T.

    2011-01-01

    The Design Analysis Branch (NE-Ml) at the Kennedy Space Center has not had the ability to accurately couple Rigid Body Dynamics (RBD) and Computational Fluid Dynamics (CFD). OVERFLOW-D is a flow solver that has been developed by NASA to have the capability to analyze and simulate dynamic motions with up to six Degrees of Freedom (6-DOF). Two simulations were prepared over the course of the internship to demonstrate 6DOF motion of rigid bodies under aerodynamic loading. The geometries in the simulations were based on a conceptual Space Launch System (SLS). The first simulation that was prepared and computed was the motion of a Solid Rocket Booster (SRB) as it separates from its core stage. To reduce computational time during the development of the simulation, only half of the physical domain with respect to the symmetry plane was simulated. Then a full solution was prepared and computed. The second simulation was a model of the SLS as it departs from a launch pad under a 20 knot crosswind. This simulation was reduced to Two Dimensions (2D) to reduce both preparation and computation time. By allowing 2-DOF for translations and 1-DOF for rotation, the simulation predicted unrealistic rotation. The simulation was then constrained to only allow translations.

  3. A method for measuring the inertia properties of rigid bodies

    NASA Astrophysics Data System (ADS)

    Gobbi, M.; Mastinu, G.; Previati, G.

    2011-01-01

    A method for the measurement of the inertia properties of rigid bodies is presented. Given a rigid body and its mass, the method allows to measure (identify) the centre of gravity location and the inertia tensor during a single test. The proposed technique is based on the analysis of the free motion of a multi-cable pendulum to which the body under consideration is connected. The motion of the pendulum and the forces acting on the system are recorded and the inertia properties are identified by means of a proper mathematical procedure based on a least square estimation. After the body is positioned on the test rig, the full identification procedure takes less than 10 min. The natural frequencies of the pendulum and the accelerations involved are quite low, making this method suitable for many practical applications. In this paper, the proposed method is described and two test rigs are presented: the first is developed for bodies up to 3500 kg and the second for bodies up to 400 kg. A validation of the measurement method is performed with satisfactory results. The test rig holds a third part quality certificate according to an ISO 9001 standard and could be scaled up to measure the inertia properties of huge bodies, such as trucks, airplanes or even ships.

  4. Absolute and relative choreographies in rigid body dynamics

    NASA Astrophysics Data System (ADS)

    Borisov, A. V.; Kilin, A. A.; Mamaev, I. S.

    2008-06-01

    For the classical problem of motion of a rigid body about a fixed point with zero area integral, we present a family of solutions that are periodic in the absolute space. Such solutions are known as choreographies. The family includes the well-known Delone solutions (for the Kovalevskaya case), some particular solutions for the Goryachev-Chaplygin case, and the Steklov solution. The “genealogy” of solutions of the family naturally appearing from the energy continuation and their connection with the Staude rotations are considered. It is shown that if the integral of areas is zero, the solutions are periodic with respect to a coordinate frame that rotates uniformly about the vertical (relative choreographies).

  5. Knowledge-i-action: an example with rigid body motion

    NASA Astrophysics Data System (ADS)

    Salvador Cabral da Costa, Sayonara; Moreira, Marco Antonio

    2005-01-01

    This paper reports the analysis of the resolution of a paper-and-pencil problem, by eight undergraduate students majoring in engineering (six) and physics (two) at the Pontifícia Universidade Católica do Rio Grande do Sul, in Porto Alegre, Brazil. The problem concerns kinetics of a rigid body, and the analysis was done in the light of Johnson-Laird’s mental models theory and Vergnaud’s conceptual fields theory. The problem-solving process has been investigated from the presentation of the problems’ variables and the pictures that followed it, up to the resolution itself. This investigation was carried out by analysing the knowledge-in-action that students have used as inferred from their written solutions and from what they said in semi-structured interviews. The findings of this analysis identified some characteristics in their answers that may help us to understand the processes used by students during the problem-solving task, with possible consequences for classroom procedures used by teachers.

  6. Dynamical analysis of an orbiting three-rigid-body system

    SciTech Connect

    Pagnozzi, Daniele E-mail: james.biggs@strath.ac.uk; Biggs, James D. E-mail: james.biggs@strath.ac.uk

    2014-12-10

    The development of multi-joint-spacecraft mission concepts calls for a deeper understanding of their nonlinear dynamics to inform and enhance system design. This paper presents a study of a three-finite-shape rigid-body system under the action of an ideal central gravitational field. The aim of this paper is to gain an insight into the natural dynamics of this system. The Hamiltonian dynamics is derived and used to identify relative attitude equilibria of the system with respect to the orbital reference frame. Then a numerical investigation of the behaviour far from the equilibria is provided using tools from modern dynamical systems theory such as energy methods, phase portraits and Poincarè maps. Results reveal a complex structure of the dynamics as well as the existence of connections between some of the equilibria. Stable equilibrium configurations appear to be surrounded by very narrow regions of regular and quasi-regular motions. Trajectories evolve on chaotic motions in the rest of the domain.

  7. Interpenetration free simulation of thin shell rigid bodies.

    PubMed

    English, R Elliot; Lentine, Michael; Fedkiw, Ron

    2013-06-01

    We propose a new algorithm for rigid body simulation that guarantees each body is in an interpenetration free state, both increasing the accuracy and robustness of the simulation as well as alleviating the need for ad hoc methods to separate bodies for subsequent simulation and rendering. We cleanly separate collision and contact resolution such that objects move and collide in the first step, with resting contact handled in the second step. The first step of our algorithm guarantees that each time step produces geometry that does not intersect or overlap by using an approximation to the continuous collision detection (and response) problem and, thus, is amenable to thin shells and degenerately flat objects moving at high speeds. In addition, we introduce a novel fail-safe that allows us to resolve all interpenetration without iterating to convergence. Since the first step guarantees a noninterfering state for the geometry, in the second step we propose a contact model for handling thin shells in proximity considering only the instantaneous locations at the ends of the time step. PMID:23559511

  8. Direct numerical simulation of rigid bodies in multiphase flow within an Eulerian framework

    NASA Astrophysics Data System (ADS)

    Rauschenberger, P.; Weigand, B.

    2015-06-01

    A new method is presented to simulate rigid body motion in the Volume-of-Fluid based multiphase code Free Surface 3D. The specific feature of the new method is that it works within an Eulerian framework without the need for a Lagrangian representation of rigid bodies. Several test cases are shown to prove the validity of the numerical scheme. The technique is able to conserve the shape of arbitrarily shaped rigid bodies and predict terminal velocities of rigid spheres. The instability of a falling ellipsoid is captured. Multiple rigid bodies including collisions may be considered using only one Volume-of-Fluid variable which allows to simulate the drafting, kissing and tumbling phenomena of two rigid spheres. The method can easily be extended to rigid bodies undergoing phase change processes.

  9. On the use of poincare surfaces of section in rigid-body motion

    NASA Astrophysics Data System (ADS)

    Broucke, Roger A.

    1993-10-01

    Poincare sections are used to classify rigid-body motion into quasiperiodic and chaotic solutions. A seven-dimensional parameter set is introduced for the attitude and kinematic variables, which is reduced to a two-dimensional set which is amenable to phase-plane analysis. This analysis is applied to the motion of a free asymmetric rigid body in space. The extension to gravity-gradient torque problems is shown.

  10. Monte Carlo-based rigid body modelling of large protein complexes against small angle scattering data.

    PubMed

    Meesters, Christian; Pairet, Bruno; Rabenhorst, Anja; Decker, Heinz; Jaenicke, Elmar

    2010-06-01

    We present a modular, collaborative, open-source architecture for rigid body modelling based upon small angle scattering data, named sas_rigid. It is designed to provide a fast and extensible scripting interface using the easy-to-learn Python programming language. Features include rigid body modelling to result in static structures and three-dimensional probability densities using two different algorithms. PMID:20598639

  11. State-variable models of structures having rigid-body modes

    NASA Technical Reports Server (NTRS)

    Craig, Roy R., Jr.; Su, Tsu-Jeng; Ni, Zhenhua

    1990-01-01

    In cases where the equations of motion of a structure having rigid-body freedom are cast in state-variable form, generalized state rigid-body modes may be needed. It is possible to find a linearly-independent set of generalized vectors which transform an n x n matrix into the almost-diagonal Jordan form. Attention is presently given to equations governing these generalized eigenvectors, together with illustrative examples of the damped and undamped structure cases.

  12. Qualification of frequency response functions using the rigid-body response

    SciTech Connect

    Smallwood, D.O.; Lauffer, J.P.

    1987-01-01

    The response of a structure at low frequencies with free boundary conditions is dominated by the rigid-body modes. The displacement shapes obtained from the low frequency values of the frequency response functions can be compared with ideal rigid-body motion to point out errors in the measurements. Insight is enhanced when the comparisons are made in the coordinate system of the measurements. Without this procedure intuition can rarely determine the proper rigid-body response at each measurement location. Typical errors identified are scaling errors, errors in location or direction, measurements with poor dynamic range and other instrumentation problems. The procedure is particularly useful when the test object is multidimensional, has a complicated geometry, has measurements in other than rectangular coordinates, and where more than one rigid-body mode is excited. It is suggested that data qualification using this method would be a useful addition to most modal tests. A least squares approach, to determine the proper rigid-body response, is reviewed and several experimental examples are given. 4 refs., 12 figs.

  13. Separating brain motion into rigid body displacement and deformation under low-severity impacts.

    PubMed

    Zou, Hong; Schmiedeler, James P; Hardy, Warren N

    2007-01-01

    The relative motion of the brain with respect to the skull has been widely studied to investigate brain injury mechanisms under impacts, but the motion patterns are not yet thoroughly understood. This work analyzes brain motion patterns using the most recent and advanced experimental relative brain/skull motion data collected under low-severity impacts. With a minimum total pseudo-strain energy, the closed-form solutions for rigid body translation and rotation were obtained by matching measured neutral density target (NDT) positions with initial NDT positions. The brain motion was thus separated into rigid body displacement and deformation. The results show that the brain has nearly pure rigid body displacement at low impact speed. As the impact becomes more severe, the increased brain motion primarily is due to deformation, while the rigid body displacement is limited in magnitude for both translation and rotation. Under low-severity impacts in the sagittal plane, the rigid body brain translation has a magnitude of 4-5 mm, and the whole brain rotation is on the order of +/-5 degrees.

  14. Attitude dynamics simulation subroutines for systems of hinge-connected rigid bodies with nonrigid appendages

    NASA Technical Reports Server (NTRS)

    Fleischer, G. E.; Likins, P. W.

    1975-01-01

    Three computer subroutines designed to solve the vector-dyadic differential equations of rotational motion for systems that may be idealized as a collection of hinge-connected rigid bodies assembled in a tree topology, with an optional flexible appendage attached to each body are reported. Deformations of the appendages are mathematically represented by modal coordinates and are assumed small. Within these constraints, the subroutines provide equation solutions for (1) the most general case of unrestricted hinge rotations, with appendage base bodies nominally rotating at a constant speed, (2) the case of unrestricted hinge rotations between rigid bodies, with the restriction that those rigid bodies carrying appendages are nominally nonspinning, and (3) the case of small hinge rotations and nominally nonrotating appendages. Sample problems and their solutions are presented to illustrate the utility of the computer programs.

  15. An incompressible smoothed particle hydrodynamics method for the motion of rigid bodies in fluids

    NASA Astrophysics Data System (ADS)

    Tofighi, N.; Ozbulut, M.; Rahmat, A.; Feng, J. J.; Yildiz, M.

    2015-09-01

    A two-dimensional incompressible smoothed particle hydrodynamics scheme is presented for simulation of rigid bodies moving through Newtonian fluids. The scheme relies on combined usage of the rigidity constraints and the viscous penalty method to simulate rigid body motion. Different viscosity ratios and interpolation schemes are tested by simulating a rigid disc descending in quiescent medium. A viscosity ratio of 100 coupled with weighted harmonic averaging scheme has been found to provide satisfactory results. The performance of the resulting scheme is systematically tested for cases with linear motion, rotational motion and their combination. The test cases include sedimentation of a single and a pair of circular discs, sedimentation of an elliptic disc and migration and rotation of a circular disc in linear shear flow. Comparison with previous results at various Reynolds numbers indicates that the proposed method captures the motion of rigid bodies driven by flow or external body forces accurately.

  16. Student understanding of the application of Newton's second law to rotating rigid bodies

    NASA Astrophysics Data System (ADS)

    Close, Hunter G.; Gomez, Luanna S.; Heron, Paula R. L.

    2013-06-01

    We report on an investigation of student understanding of rigid body dynamics in which we asked students in introductory calculus-based physics to compare the translational motions of identical rigid bodies subject to forces that differed only in the point of contact at which they were applied. There was a widespread tendency to claim that forces that cause rotational motion have a diminished effect on translational motion. A series of related problems was developed to examine whether similar errors would be made in other contexts, and interviews were conducted to probe student thinking in greater depth. In this paper, we describe the results of our investigation and also describe a series of different interventions that culminated in the development of a tutorial that improves student ability to apply Newton's second law to rotating rigid bodies.

  17. Computing the Free Energy along a Reaction Coordinate Using Rigid Body Dynamics.

    PubMed

    Tao, Peng; Sodt, Alexander J; Shao, Yihan; König, Gerhard; Brooks, Bernard R

    2014-10-14

    The calculations of potential of mean force along complex chemical reactions or rare events pathways are of great interest because of their importance for many areas in chemistry, molecular biology, and material science. The major difficulty for free energy calculations comes from the great computational cost for adequate sampling of the system in high-energy regions, especially close to the reaction transition state. Here, we present a method, called FEG-RBD, in which the free energy gradients were obtained from rigid body dynamics simulations. Then the free energy gradients were integrated along a reference reaction pathway to calculate free energy profiles. In a given system, the reaction coordinates defining a subset of atoms (e.g., a solute, or the quantum mechanics (QM) region of a quantum mechanics/molecular mechanics simulation) are selected to form a rigid body during the simulation. The first-order derivatives (gradients) of the free energy with respect to the reaction coordinates are obtained through the integration of constraint forces within the rigid body. Each structure along the reference reaction path is separately subjected to such a rigid body simulation. The individual free energy gradients are integrated along the reference pathway to obtain the free energy profile. Test cases provided demonstrate both the strengths and weaknesses of the FEG-RBD method. The most significant benefit of this method comes from the fast convergence rate of the free energy gradient using rigid-body constraints instead of restraints. A correction to the free energy due to approximate relaxation of the rigid-body constraint is estimated and discussed. A comparison with umbrella sampling using a simple test case revealed the improved sampling efficiency of FEG-RBD by a factor of 4 on average. The enhanced efficiency makes this method effective for calculating the free energy of complex chemical reactions when the reaction coordinate can be unambiguously defined by a

  18. Virtual rigid body: a new optical tracking paradigm in image-guided interventions

    NASA Astrophysics Data System (ADS)

    Cheng, Alexis; Lee, David S.; Deshmukh, Nishikant; Boctor, Emad M.

    2015-03-01

    Tracking technology is often necessary for image-guided surgical interventions. Optical tracking is one the options, but it suffers from line of sight and workspace limitations. Optical tracking is accomplished by attaching a rigid body marker, having a pattern for pose detection, onto a tool or device. A larger rigid body results in more accurate tracking, but at the same time large size limits its usage in a crowded surgical workspace. This work presents a prototype of a novel optical tracking method using a virtual rigid body (VRB). We define the VRB as a 3D rigid body marker in the form of pattern on a surface generated from a light source. Its pose can be recovered by observing the projected pattern with a stereo-camera system. The rigid body's size is no longer physically limited as we can manufacture small size light sources. Conventional optical tracking also requires line of sight to the rigid body. VRB overcomes these limitations by detecting a pattern projected onto the surface. We can project the pattern onto a region of interest, allowing the pattern to always be in the view of the optical tracker. This helps to decrease the occurrence of occlusions. This manuscript describes the method and results compared with conventional optical tracking in an experiment setup using known motions. The experiments are done using an optical tracker and a linear-stage, resulting in targeting errors of 0.38mm+/-0.28mm with our method compared to 0.23mm+/-0.22mm with conventional optical markers. Another experiment that replaced the linear stage with a robot arm resulted in rotational errors of 0.50+/-0.31° and 2.68+/-2.20° and the translation errors of 0.18+/-0.10 mm and 0.03+/-0.02 mm respectively.

  19. A penalty immersed boundary method for a rigid body in fluid

    NASA Astrophysics Data System (ADS)

    Kim, Yongsam; Peskin, Charles S.

    2016-03-01

    We extend the penalty immersed boundary (pIB) method to the interaction between a rigid body and a surrounding fluid. The pIB method is based on the idea of splitting an immersed boundary, which here is a rigid body, notionally into two Lagrangian components: one is a massive component carrying all mass of the rigid body and the other is massless. These two components are connected by a system of stiff springs with 0 rest length. The massless component interacts with the surrounding fluid: it moves at the local fluid velocity and exerts force locally on the fluid. The massive component has no direct interaction with the surrounding fluid and behaves as though in a vacuum, following the dynamics of a rigid body, in which the acting forces and torques are generated from the system of stiff springs that connects the two Lagrangian components. We verify the pIB method by computing the drag coefficients of a cylinder and ball descending though a fluid under the influence of gravity and also by studying the interaction of two such descending cylinders and likewise the interaction of two such descending balls. The computational results are quite comparable to those in the literature. As a further example of an application, we include a freely falling maple seed with autorotation.

  20. Lorentz Contraction, Bell's Spaceships and Rigid Body Motion in Special Relativity

    ERIC Educational Resources Information Center

    Franklin, Jerrold

    2010-01-01

    The meaning of Lorentz contraction in special relativity and its connection with Bell's spaceships parable is discussed. The motion of Bell's spaceships is then compared with the accelerated motion of a rigid body. We have tried to write this in a simple form that could be used to correct students' misconceptions due to conflicting earlier…

  1. Numerical simulation of a moving rigid body in a rarefied gas

    NASA Astrophysics Data System (ADS)

    Shrestha, Samir; Tiwari, Sudarshan; Klar, Axel; Hardt, Steffen

    2015-07-01

    In this paper we present a numerical scheme to simulate a moving rigid body with arbitrary shape suspended in a rarefied gas. The rarefied gas is simulated by solving the Boltzmann equation using a DSMC particle method. The motion of the rigid body is governed by the Newton-Euler equations, where the force and the torque on the rigid body are computed from the momentum transfer of the gas molecules colliding with the body. On the other hand, the motion of the rigid body influences the gas flow in its surroundings. We validate the numerical scheme by considering a moving piston problem in 1D and the Einstein relation for Brownian motion of the suspended particle in 3D. In the piston problem it is shown that the equilibrium position of the moving piston converges to the analytical solution for a wide range of Knudsen numbers. In the case of Brownian motion the translational as well as the rotational degrees of freedom are taken into account. In this case it is shown that the numerically computed translational and rotational diffusion coefficients converge to the theoretical values. Finally, the motion of an object of complex shape under the influence of a thermophoretic force is investigated.

  2. Periodic solutions in the Kovalevskaya case of a rigid body in rotation about a fixed point

    NASA Astrophysics Data System (ADS)

    El-Sabaa, F. M. F.

    1992-07-01

    The method of small parameters introduced by Poincare is used to obtain the period solution of the problem of a rigid body in the Kovalevskaya case with k (the Kovalevskaya constant of integration) as a small parameter. The asymptotic solution is obtained in terms of elliptic integrals for the (complete integrable) Kovalevskaya top.

  3. Aquatic turning performance of painted turtles (Chrysemys picta) and functional consequences of a rigid body design.

    PubMed

    Rivera, Gabriel; Rivera, Angela R V; Dougherty, Erin E; Blob, Richard W

    2006-11-01

    The ability to capture prey and avoid predation in aquatic habitats depends strongly on the ability to perform unsteady maneuvers (e.g. turns), which itself depends strongly on body flexibility. Two previous studies of turning performance in rigid-bodied taxa have found either high maneuverability or high agility, but not both. However, examinations of aquatic turning performance in rigid-bodied animals have had limited taxonomic scope and, as such, the effects of many body shapes and designs on aquatic maneuverability and agility have yet to be examined. Turtles represent the oldest extant lineage of rigid-bodied vertebrates and the only aquatic rigid-bodied tetrapods. We evaluated the aquatic turning performance of painted turtles, Chrysemys picta (Schneider, 1783) using the minimum length-specific radius of the turning path (R/L) and the average turning rate (omega(avg)) as measures of maneuverability and agility, respectively. We filmed turtles conducting forward and backward turns in an aquatic arena. Each type of turn was executed using a different pattern of limb movements. During forward turns, turtles consistently protracted the inboard forelimb and held it stationary into the flow, while continuing to move the outboard forelimb and both hindlimbs as in rectilinear swimming. The limb movements of backward turns were more complex than those of forward turns, but involved near simultaneous retraction and protraction of contralateral fore- and hindlimbs, respectively. Forward turns had a minimum R/L of 0.0018 (the second single lowest value reported from any animal) and a maximum omega(avg) of 247.1 degrees. Values of R/L for backward turns (0.0091-0.0950 L) were much less variable than that of forward turns (0.0018-1.0442 L). The maneuverability of turtles is similar to that recorded previously for rigid-bodied boxfish. However, several morphological features of turtles (e.g. shell morphology and limb position) appear to increase agility relative to the body

  4. Almost global finite-time stabilization of rigid body attitude motion

    NASA Astrophysics Data System (ADS)

    Bohn, Jan

    This dissertation considers continuous finite-time stabilization of rigid body attitude dynamics using a coordinate-free representation of attitude on the Lie group of rigid body rotations in three dimensions, SO(3). First a general methodology to construct control Lyapunov functions that are Holder continuous and that can be used to show finite-time stability of the feedback controlled system, is presented. The dynamics is represented by generalized (local) coordinates. This methodology is then extended, using a Holder continuous Morse-Lyapunov function, to obtain a finite-time feedback stabilization scheme for rigid body attitude motion to a desired attitude with continuous state feedback. The feedback control law designed here leads to almost global finite-time stabilization of the attitude motion of a rigid body with Holder continuous feedback, to the desired attitude. Furthermore, using the finite-time feedback stabilization scheme, a state observer is proposed for rigid body attitude motion with a given attitude dynamics model that in the absence of measurement noise and disturbance torques leads to almost global finite-time stable convergence of attitude motion state estimates to the actual states for a rigid body whose inertia is known. Subsequently this state observer is combined with a deterministic filter scheme that utilizes a set of sigma points obtained from the unscented transform based on exponential coordinates. This estimation scheme uses discrete-time state measurements of inertially known vectors along with rate gyro measurements of the angular velocity, to obtain state estimates in the filtering stage. Additionally, a set of sigma points is obtained from the unscented transform, with re-sampling centered at the current state estimate at each measurement instant. The state estimates along with sampled sigma points are propagated between measurement instants, using the discrete-time attitude state observer that is almost globally finite

  5. Planar dynamics of a uniform beam with rigid bodies affixed to the ends

    NASA Technical Reports Server (NTRS)

    Storch, J.; Gates, S.

    1983-01-01

    The planar dynamics of a uniform elastic beam subject to a variety of geometric and natural boundary conditions and external excitations were analyzed. The beams are inextensible and capable of small transverse bending deformations only. Classical beam vibration eigenvalue problems for a cantilever with tip mass, a cantilever with tip body and an unconstrained beam with rigid bodies at each are examined. The characteristic equations, eigenfunctions and orthogonality relations for each are derived. The forced vibration of a cantilever with tip body subject to base acceleration is analyzed. The exact solution of the governing nonhomogeneous partial differential equation with time dependent boundary conditions is presented and compared with a Rayleigh-Ritz approximate solution. The arbitrary planar motion of an elastic beam with rigid bodies at the ends is addressed. Equations of motion are derived for two modal expansions of the beam deflection. The motion equations are cast in a first order form suitable for numerical integration. Selected FORTRAN programs are provided.

  6. Compliant mechanism road bicycle brake: a rigid-body replacement case study

    SciTech Connect

    Olsen, Brian M; Howell, Larry L; Magleby, Spencer P

    2011-01-19

    The design of high-performance bicycle brakes is complicated by the competing design objectives of increased performance and low weight. But this challenge also provides a good case study to demonstrate the design of compliant mechanisms to replace current rigid-link mechanisms. This paper briefly reviews current road brake designs, demonstrates the use of rigid-body replacement synthesis to design a compliant mechanism, and illustrates the combination of compliant mechanism design tools. The resulting concept was generated from the modified dual-pivot brake design and is a partially compliant mechanism where one pin has the dual role of a joint and a mounting pin. The pseudo-rigid-body model, finite element analysis, and optimization algorithms are used to generate design dimensions, and designs are considered for both titanium and E-glass flexures. The resulting design has the potential of reducing the part count and overall weight while maintaining a performance similar to the benchmark.

  7. Mutual potential between two rigid bodies with arbitrary shapes and mass distributions

    NASA Astrophysics Data System (ADS)

    Hou, Xiyun; Scheeres, Daniel J.; Xin, Xiaosheng

    2016-09-01

    Formulae to compute the mutual potential, force, and torque between two rigid bodies are given. These formulae are expressed in Cartesian coordinates using inertia integrals. They are valid for rigid bodies with arbitrary shapes and mass distributions. By using recursive relations, these formulae can be easily implemented on computers. Comparisons with previous studies show their superiority in computation speed. Using the algorithm as a tool, the planar problem of two ellipsoids is studied. Generally, potential truncated at the second order is good enough for a qualitative description of the mutual dynamics. However, for ellipsoids with very large non-spherical terms, higher order terms of the potential should be considered, at the cost of a higher computational cost. Explicit formulae of the potential truncated to the fourth order are given.

  8. Problems in rigid body dynamics and in applied gyroscope theory: Analytical methods

    NASA Astrophysics Data System (ADS)

    Koshliakov, V. N.

    Analytical methods are presented for solving certain problems in rigid body mechanics and applied gyroscope theory. In particular, consideration is given to classical problems in the dynamics of a heavy rigid body rotating about a fixed point. The methods proposed here are illustrated by using the Kowalevski and Goriachev-Chaplygin spinning tops as an example. A class of exact solutions to equations of motion for a gyrocompass is obtained, and the effect of resistance forces on the motion of a vertical gyroscope is analyzed; the deviations of a vertical gyroscope under nonstationary rotation of the gyroscope rotor are investigated. Special attention is given to methods for solving the problem of stability of gyrocompasses and adjustable gyrohorizon-compasses on a maneuvering ship.

  9. Topological classification of the Goryachev integrable case in rigid body dynamics

    NASA Astrophysics Data System (ADS)

    Nikolaenko, S. S.

    2016-01-01

    A topological analysis of the Goryachev integrable case in rigid body dynamics is made on the basis of the Fomenko-Zieschang theory. The invariants (marked molecules) which are obtained give a complete description, from the standpoint of Liouville classification, of the systems of Goryachev type on various level sets of the energy. It turns out that on appropriate energy levels the Goryachev case is Liouville equivalent to many classical integrable systems and, in particular, the Joukowski, Clebsch, Sokolov and Kovalevskaya-Yehia cases in rigid body dynamics, as well as to some integrable billiards in plane domains bounded by confocal quadrics -- in other words, the foliations given by the closures of generic solutions of these systems have the same structure. Bibliography: 15 titles.

  10. The phase topology of a special case of Goryachev integrability in rigid body dynamics

    SciTech Connect

    Ryabov, P. E.

    2014-07-31

    The phase topology of a special case of Goryachev integrability in the problem of motion of a rigid body in a fluid is investigated using the method of Boolean functions, which was developed by Kharlamov for algebraically separated systems. The bifurcation diagram of the moment map is found and the Fomenko invariant, which classifies the systems up to rough Liouville equivalence, is specified. Bibliography: 15 titles. (paper)

  11. Hamilton's Equations with Euler Parameters for Rigid Body Dynamics Modeling. Chapter 3

    NASA Technical Reports Server (NTRS)

    Shivarama, Ravishankar; Fahrenthold, Eric P.

    2004-01-01

    A combination of Euler parameter kinematics and Hamiltonian mechanics provides a rigid body dynamics model well suited for use in strongly nonlinear problems involving arbitrarily large rotations. The model is unconstrained, free of singularities, includes a general potential energy function and a minimum set of momentum variables, and takes an explicit state space form convenient for numerical implementation. The general formulation may be specialized to address particular applications, as illustrated in several three dimensional example problems.

  12. Stabilization of the rotational motion of a rigid body on a vibrating base

    NASA Astrophysics Data System (ADS)

    Krementulo, V. V.

    1984-12-01

    The problem of the optimum (in a certain sense) stabilization of the permanent rotation of a heavy rigid body on a vibrating base is solved in the context of analytical control theory. Stabilization is achieved by means of a gimbal-suspended balanced gyroscope controlled by three moments. The control moments, obtained in explicit form, ensure the asymptotic stability of the rotational motion of the body along all of its phase coordinates and a minimum of a certain integral functional.

  13. Some suggested approaches to solving the Hamilton-Jacobi equation associated with constrained rigid body motion

    NASA Technical Reports Server (NTRS)

    Fitzpatrick, P. M.; Harmon, G. R.; Cochran, J. E.; Shaw, W. A.

    1974-01-01

    Some methods of approaching a solution to the Hamilton-Jacobi equation are outlined and examples are given to illustrate particular methods. These methods may be used for cases where the Hamilton-Jacobi equation is not separable and have been particularly useful in solving the rigid body motion of an earth satellite subjected to gravity torques. These general applications may also have usefulness in studying the motion of satellites with aerodynamic torque and in studying space vehicle motion where thrusting is involved.

  14. Estimation of motion parameters for a rigid body from its orthogonal projection

    NASA Technical Reports Server (NTRS)

    Ganguly, S.; Ghosh, B.; Tarn, T. J.; Bejczy, A. K.

    1989-01-01

    An estimate is presented of the motion parameters, namely, linear and angular velocities of a rigid body rotating and translating in three-dimensional-space. It is assumed that the velocities are constant and that only the orthogonal projection of the motion is observable. In particular, if (x, y, z) is the Cartesian coordinate, it is assumed that the projection of the motion on the x-y plane is observed and the information along the z coordinate is lost.

  15. New conditional integrable cases of motion of a rigid body with Kovalevskaya's configuration

    NASA Astrophysics Data System (ADS)

    Yehia, H. M.; Elmandouh, A. A.

    2011-01-01

    We consider the general problem of motion of a rigid body about a fixed point under the action of an axisymmetric combination of potential and gyroscopic forces. We introduce two new cases of this problem which are integrable on the zero level of the cyclic integral. The new cases are combined generalizations of several previously known ones, namely those of Kovalevskaya, Yehia, Sokolov, Yehia and Bedweihi and Goriatchev, by the introduction of additional parameters to the structure of each.

  16. A new pre-loaded beam geometric stiffness matrix with full rigid body capabilities

    NASA Technical Reports Server (NTRS)

    Bosela, P. A.; Fertis, D. G.; Shaker, F. J.

    1992-01-01

    Space structures, such as the Space Station solar arrays, must be extremely light-weight, flexible structures. Accurate prediction of the natural frequencies and mode shapes is essential for determining the structural adequacy of components, and designing a controls system. The tension pre-load in the 'blanket' of photovoltaic solar collectors, and the free/free boundary conditions of a structure in space, causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomenon known as 'grounding', or false stiffening, of the stiffness matrix occurs during rigid body rotation. The authors have previously shown that the grounding phenomenon is caused by a lack of rigid body rotational capability, and is typical in beam geometric stiffness matrices formulated by others, including those which contain higher order effects. The cause of the problem was identified as the force imbalance inherent in the formulations. In this paper, the authors develop a beam geometric stiffness matrix for a directed force problem, and show that the resultant global stiffness matrix contains complete rigid body mode capabilities, and performs very well in the diagonalization methodology customarily used in dynamic analysis.

  17. Strongly coupled dynamics of fluids and rigid-body systems with the immersed boundary projection method

    NASA Astrophysics Data System (ADS)

    Wang, Chengjie; Eldredge, Jeff D.

    2015-08-01

    A strong coupling algorithm is presented for simulating the dynamic interactions between incompressible viscous flows and rigid-body systems in both two- and three-dimensional problems. In this work, the Navier-Stokes equations for incompressible flow are solved on a uniform Cartesian grid by the vorticity-based immersed boundary projection method of Colonius and Taira. Dynamical equations for arbitrary rigid-body systems are also developed. The proposed coupling method attempts to unify the treatment of constraints in the fluid and structure-the incompressibility of the fluid, the linkages in the rigid-body system, and the conditions at the interface-through the use of Lagrange multipliers. The resulting partitioned system of equations is solved with a simple relaxation scheme, based on an identification of virtual inertia from the fluid. The scheme achieves convergence in only 2 to 5 iterations per time step for a wide variety of mass ratios. The formulation requires that only a subset of the discrete fluid equations be solved in each iteration. Several two- and three-dimensional numerical tests are conducted to validate and demonstrate the method, including a falling cylinder, flapping of flexible wings, self-excited oscillations of a system of many linked plates in a free stream, and passive pivoting of a finite aspect ratio plate under the influence of gravity in a free stream. The results from the current method are compared with previous experimental and numerical results and good agreement is achieved.

  18. An Interface for Specifying Rigid-Body Motions for CFD Applications

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.; Chan, William; Aftosmis, Michael; Meakin, Robert L.; Kwak, Dochan (Technical Monitor)

    2003-01-01

    An interface for specifying rigid-body motions for CFD applications is presented. This interface provides a means of describing a component hierarchy in a geometric configuration, as well as the motion (prescribed or six-degree-of-freedom) associated with any component. The interface consists of a general set of datatypes, along with rules for their interaction, and is designed to be flexible in order to evolve as future needs dictate. The specification is currently implemented with an XML file format which is portable across platforms and applications. The motion specification is capable of describing general rigid body motions, and eliminates the need to write and compile new code within the application software for each dynamic configuration, allowing client software to automate dynamic simulations. The interface is integrated with a GUI tool which allows rigid body motions to be prescribed and verified interactively, promoting access to non-expert users. Illustrative examples, as well as the raw XML source of the file specifications, are included.

  19. Rigid Body Modes Influence On Microvibration Analysis-Application To Swarm

    NASA Astrophysics Data System (ADS)

    Laduree, G.; Fransen, S.; Baldesi, G.; Pflieger, I.

    2012-07-01

    Microvibrations are defined as low level mechanical disturbances affecting payload performance, generated by mobile parts or mechanism operating on-board the spacecraft, like momentum or reaction wheels, pointing mechanism, cryo-coolers or thrusters. The disturbances caused by these sources are transmitted through the spacecraft structure and excite modes of that structure or elements of the payload impacting its performance (e.g. Line of sight rotations inducing some image quality degradation). The dynamic interaction between these three elements (noise source, spacecraft structure and sensitive receiver) makes the microvibration prediction a delicate problem. Microvibration sources are generally of concern in the frequency range from a few Hz to 1000 Hz. However, in some specific cases, high stability at lower frequencies might be requested. This is the case of the SWARM mission, whose objectives are to provide the best ever survey of the geomagnetic field and its temporal evolution as well as supplementary information for studying the interaction of the magnetic field with other physical quantities describing the Earth system (e.g. ocean circulation). Among its instruments, SWARM is embarking a very sensitive 6-axis accelerometer in the low frequency range (10-8 m/s2 or rad/s2 between 10-4 and 0.1 Hz) located at its Centre of Gravity and an Absolute Scalar Magnetometer located at the tip of a boom far from the spacecraft body. The ASM performs its measurements by rotating an alternative magnetic field around its main axis thanks to a piezo-electric motor. This repeated disturbance might generate some pollution of the accelerometer science data. The objective of this work is to focus on the interaction of the rigid body mode calculation method with the elastic contribution of the normal modes excited by the noise source frequency content. It has indeed been reported in the past that NASTRAN Lanczos rigid body modes may lead to inaccurate rigid-body accelerations

  20. Aquatic turning performance of painted turtles (Chrysemys picta) and functional consequences of a rigid body design.

    PubMed

    Rivera, Gabriel; Rivera, Angela R V; Dougherty, Erin E; Blob, Richard W

    2006-11-01

    The ability to capture prey and avoid predation in aquatic habitats depends strongly on the ability to perform unsteady maneuvers (e.g. turns), which itself depends strongly on body flexibility. Two previous studies of turning performance in rigid-bodied taxa have found either high maneuverability or high agility, but not both. However, examinations of aquatic turning performance in rigid-bodied animals have had limited taxonomic scope and, as such, the effects of many body shapes and designs on aquatic maneuverability and agility have yet to be examined. Turtles represent the oldest extant lineage of rigid-bodied vertebrates and the only aquatic rigid-bodied tetrapods. We evaluated the aquatic turning performance of painted turtles, Chrysemys picta (Schneider, 1783) using the minimum length-specific radius of the turning path (R/L) and the average turning rate (omega(avg)) as measures of maneuverability and agility, respectively. We filmed turtles conducting forward and backward turns in an aquatic arena. Each type of turn was executed using a different pattern of limb movements. During forward turns, turtles consistently protracted the inboard forelimb and held it stationary into the flow, while continuing to move the outboard forelimb and both hindlimbs as in rectilinear swimming. The limb movements of backward turns were more complex than those of forward turns, but involved near simultaneous retraction and protraction of contralateral fore- and hindlimbs, respectively. Forward turns had a minimum R/L of 0.0018 (the second single lowest value reported from any animal) and a maximum omega(avg) of 247.1 degrees. Values of R/L for backward turns (0.0091-0.0950 L) were much less variable than that of forward turns (0.0018-1.0442 L). The maneuverability of turtles is similar to that recorded previously for rigid-bodied boxfish. However, several morphological features of turtles (e.g. shell morphology and limb position) appear to increase agility relative to the body

  1. Dynamic analysis of a system of hinge-connected rigid bodies with nonrigid appendages. [equations of motion

    NASA Technical Reports Server (NTRS)

    Likins, P. W.

    1974-01-01

    Equations of motion are derived for use in simulating a spacecraft or other complex electromechanical system amenable to idealization as a set of hinge-connected rigid bodies of tree topology, with rigid axisymmetric rotors and nonrigid appendages attached to each rigid body in the set. In conjunction with a previously published report on finite-element appendage vibration equations, this report provides a complete minimum-dimension formulation suitable for generic programming for digital computer numerical integration.

  2. Fast time-reversible algorithms for molecular dynamics of rigid-body systems

    NASA Astrophysics Data System (ADS)

    Kajima, Yasuhiro; Hiyama, Miyabi; Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki

    2012-06-01

    In this paper, we present time-reversible simulation algorithms for rigid bodies in the quaternion representation. By advancing a time-reversible algorithm [Y. Kajima, M. Hiyama, S. Ogata, and T. Tamura, J. Phys. Soc. Jpn. 80, 114002 (2011), 10.1143/JPSJ.80.114002] that requires iterations in calculating the angular velocity at each time step, we propose two kinds of iteration-free fast time-reversible algorithms. They are easily implemented in codes. The codes are compared with that of existing algorithms through demonstrative simulation of a nanometer-sized water droplet to find their stability of the total energy and computation speeds.

  3. Gravitational waves from rotating and precessing rigid bodies. 2: General solutions and computationally useful formulae

    NASA Technical Reports Server (NTRS)

    Zimmerman, M.

    1979-01-01

    The classical mechanics results for free precession which are needed in order to calculate the weak field, slow-motion, quadrupole-moment gravitational waves are reviewed. Within that formalism, algorithms are given for computing the exact gravitational power radiated and waveforms produced by arbitrary rigid-body freely-precessing sources. The dominant terms are presented in series expansions of the waveforms for the case of an almost spherical object precessing with a small wobble angle. These series expansions, which retain the precise frequency dependence of the waves, may be useful for gravitational astronomers when freely-precessing sources begin to be observed.

  4. An implicit time-stepping scheme for rigid body dynamics with Coulomb friction

    SciTech Connect

    STEWART,DAVID; TRINKLE,JEFFREY C.

    2000-02-15

    In this paper a new time-stepping method for simulating systems of rigid bodies is given. Unlike methods which take an instantaneous point of view, the method is based on impulse-momentum equations, and so does not need to explicitly resolve impulsive forces. On the other hand, the method is distinct from previous impulsive methods in that it does not require explicit collision checking and it can handle simultaneous impacts. Numerical results are given for one planar and one three-dimensional example, which demonstrate the practicality of the method, and its convergence as the step size becomes small.

  5. Dynamical models for a spacecraft idealized as a set of multi-hinged rigid bodies

    NASA Technical Reports Server (NTRS)

    Larson, V.

    1973-01-01

    A brief description is presented of a canonical set of equations which governs the behavior of an n-body spacecraft. General results are given for the case in which the spacecraft is modeled in terms of n rigid bodies connected by dissipative elastic joints. The final equations are free from constraint torques and involve only r variables (r is the number of degrees of freedom of the system). An advantage which accompanies the elimination of the constraint torques is a decrease in the computer run time (especially when n is large).

  6. Analytic Theory and Control of the Motion of Spinning Rigid Bodies

    NASA Technical Reports Server (NTRS)

    Tsiotras, Panagiotis

    1993-01-01

    Numerical simulations are often resorted to, in order to understand the attitude response and control characteristics of a rigid body. However, this approach in performing sensitivity and/or error analyses may be prohibitively expensive and time consuming, especially when a large number of problem parameters are involved. Thus, there is an important role for analytical models in obtaining an understanding of the complex dynamical behavior. In this dissertation, new analytic solutions are derived for the complete attitude motion of spinning rigid bodies, under minimal assumptions. Hence, we obtain the most general solutions reported in the literature so far. Specifically, large external torques and large asymmetries are included in the problem statement. Moreover, problems involving large angular excursions are treated in detail. A new tractable formulation of the kinematics is introduced which proves to be extremely helpful in the search for analytic solutions of the attitude history of such kinds of problems. The main utility of the new formulation becomes apparent however, when searching for feedback control laws for stabilization and/or reorientation of spinning spacecraft. This is an inherently nonlinear problem, where standard linear control techniques fail. We derive a class of control laws for spin axis stabilization of symmetric spacecraft using only two pairs of gas jet actuators. Practically, this could correspond to a spacecraft operating in failure mode, for example. Theoretically, it is also an important control problem which, because of its difficulty, has received little, if any, attention in the literature. The proposed control laws are especially simple and elegant. A feedback control law that achieves arbitrary reorientation of the spacecraft is also derived, using ideas from invariant manifold theory. The significance of this research is twofold. First, it provides a deeper understanding of the fundamental behavior of rigid bodies subject to body

  7. Fast time-reversible algorithms for molecular dynamics of rigid-body systems.

    PubMed

    Kajima, Yasuhiro; Hiyama, Miyabi; Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki

    2012-06-21

    In this paper, we present time-reversible simulation algorithms for rigid bodies in the quaternion representation. By advancing a time-reversible algorithm [Y. Kajima, M. Hiyama, S. Ogata, and T. Tamura, J. Phys. Soc. Jpn. 80, 114002 (2011)] that requires iterations in calculating the angular velocity at each time step, we propose two kinds of iteration-free fast time-reversible algorithms. They are easily implemented in codes. The codes are compared with that of existing algorithms through demonstrative simulation of a nanometer-sized water droplet to find their stability of the total energy and computation speeds. PMID:22779579

  8. Detection of micromechanical deformation under rigid body displacement using twin-pulsed 3D digital holography

    NASA Astrophysics Data System (ADS)

    Perez-Lopez, Carlos; Hernandez-Montes, Maria del Socorro; Mendoza-Santoyo, Fernando

    2005-02-01

    Twin-pulsed digital holography in its 3D set up is used to recover exclusively the micro-mechanical deformation of an object. The test object is allowed to have rigid body movements such as rotation and translation, with the result that the fringe patterns contain information of the latter and the object deformation, a feature that may significantly modify the interpretation of the results. Experimental results from a flat metal plate subject to micro stress and a displacement in the x-z plane are presented to demonstrate that using this optical method it is possible to recover exclusively the contribution of the micro stress.

  9. Model-based registration of multi-rigid-body for augmented reality

    NASA Astrophysics Data System (ADS)

    Ikeda, Sei; Hori, Hajime; Imura, Masataka; Manabe, Yoshitsugu; Chihara, Kunihiro

    2009-02-01

    Geometric registration between a virtual object and the real space is the most basic problem in augmented reality. Model-based tracking methods allow us to estimate three-dimensional (3-D) position and orientation of a real object by using a textured 3-D model instead of visual marker. However, it is difficult to apply existing model-based tracking methods to the objects that have movable parts such as a display of a mobile phone, because these methods suppose a single, rigid-body model. In this research, we propose a novel model-based registration method for multi rigid-body objects. For each frame, the 3-D models of each rigid part of the object are first rendered according to estimated motion and transformation from the previous frame. Second, control points are determined by detecting the edges of the rendered image and sampling pixels on these edges. Motion and transformation are then simultaneously calculated from distances between the edges and the control points. The validity of the proposed method is demonstrated through experiments using synthetic videos.

  10. A boundary integral approach to the scattering of nonplanar acoustic waves by rigid bodies

    NASA Technical Reports Server (NTRS)

    Gallman, Judith M.; Myers, M. K.; Farassat, F.

    1990-01-01

    The acoustic scattering of an incident wave by a rigid body can be described by a singular Fredholm integral equation of the second kind. This equation is derived by solving the wave equation using generalized function theory, Green's function for the wave equation in unbounded space, and the acoustic boundary condition for a perfectly rigid body. This paper will discuss the derivation of the wave equation, its reformulation as a boundary integral equation, and the solution of the integral equation by the Galerkin method. The accuracy of the Galerkin method can be assessed by applying the technique outlined in the paper to reproduce the known pressure fields that are due to various point sources. From the analysis of these simpler cases, the accuracy of the Galerkin solution can be inferred for the scattered pressure field caused by the incidence of a dipole field on a rigid sphere. The solution by the Galerkin technique can then be applied to such problems as a dipole model of a propeller whose pressure field is incident on a rigid cylinder. This is the groundwork for modeling the scattering of rotating blade noise by airplane fuselages.

  11. Rigid body mode identification of the PAH-2 helicopter using the eigensystem realization algorithm

    NASA Technical Reports Server (NTRS)

    Schenk, Axel; Pappa, Richard S.

    1992-01-01

    The rigid body modes of the PAH-2 'Tiger' helicopter were identified using the Eigensystem Realization Algorithm (ERA). This work complements ground vibration tests performed using DLR's traditional phase resonance technique and the ISSPA (Identification of Structural System Parameters) method. Rigid body modal parameters are important for ground resonance prediction. Time-domain data for ERA were obtained by inverse Fourier transformation of frequency response functions measured with stepped-sine excitation. Mode purity (based on the Phase Resonance Criterion) was generally equal to or greater than corresponding results obtained in the ground vibration tests. All identified natural frequencies and mode shapes correlate well with corresponding ground vibration test results. The modal identification approach discussed in this report has become increasingly attractive in recent years due to the steadily declining cost and increased performance of scientific computers. As illustrated in this application, modern time-domain methods can be successfully applied to data acquired using DLR's existing test equipment. Some suggestions are made for future applications of time domain modal identification in this manner.

  12. A Computational Model for Suspended Large Rigid Bodies in 3D Unsteady Viscous Flows

    NASA Astrophysics Data System (ADS)

    Xiao, Feng

    1999-11-01

    A 3D numerical model for computing large rigid objects suspended in fluid flow has been developed. Rather than calculating the surface pressure upon the solid body, we evaluate the net force and torque based on a volume force formulation. The total effective force is obtained by summing up the forces at the Eulerian grids occupied by the rigid body. The effects of the moving bodies are coupled to the fluid flow by imposing the velocity field of the bodies to the fluid. A Poisson equation is used to compute the pressure over the whole domain. The objects are identified by color functions and calculated by the PPM scheme and a tangent function transformation which scales the transition region of the computed interface to a compact thickness. The model is then implemented on a parallel computer of distributed memory and validated with Stokes and low Reynolds number flows.

  13. The problem of exact interior solutions for rotating rigid bodies in general relativity

    NASA Technical Reports Server (NTRS)

    Wahlquist, H. D.

    1993-01-01

    The (3 + 1) dyadic formalism for timelike congruences is applied to derive interior solutions for stationary, axisymmetric, rigidly rotating bodies. In this approach the mathematics is formulated in terms of three-space-covariant, first-order, vector-dyadic, differential equations for a and Omega, the acceleration and angular velocity three-vectors of the rigid body; for T, the stress dyadic of the matter; and for A and B, the 'electric' and 'magnetic' Weyl curvature dyadics which describe the gravitational field. It is shown how an appropriate ansatz for the forms of these dyadics can be used to discover exact rotating interior solutions such as the perfect fluid solution first published in 1968. By incorporating anisotropic stresses, a generalization is found of that previous solution and, in addition, a very simple new solution that can only exist in toroidal configurations.

  14. Identification of motion parameters of a rigid body from its orthogonal and perspective projections

    NASA Technical Reports Server (NTRS)

    Ganguly, S.; Ghosh, B.; Tarn, T. J.; Bejczy, A. K.

    1989-01-01

    An estimate is made of the motion parameters, namely, linear and angular velocities, of a rigid body rotating and translating in three-space. The authors assume that the velocities are constant and that the motion is not completely observable. They consider two separate cases of partial observations corresponding to the orthogonal and the perspective projections, respectively. If (x, y, z) is the Cartesian coordinate of the three-space, the authors assume in the first case that the projection of the motion on the x-y plane is observed. If (r, theta, phi) is the polar coordinates of the three-space, they assume in the second case that the parameter vector (theta, phi) is observed. The use of both of these cases to estimate the motion parameters is discussed.

  15. Implementation of Kane's Method for a Spacecraft Composed of Multiple Rigid Bodies

    NASA Technical Reports Server (NTRS)

    Stoneking, Eric T.

    2013-01-01

    Equations of motion are derived for a general spacecraft composed of rigid bodies connected via rotary (spherical or gimballed) joints in a tree topology. Several supporting concepts are developed in depth. Basis dyads aid in the transition from basis-free vector equations to component-wise equations. Joint partials allow abstraction of 1-DOF, 2-DOF, 3-DOF gimballed and spherical rotational joints to a common notation. The basic building block consisting of an "inner" body and an "outer" body connected by a joint enables efficient organization of arbitrary tree structures. Kane's equation is recast in a form which facilitates systematic assembly of large systems of equations, and exposes a relationship of Kane's equation to Newton and Euler's equations which is obscured by the usual presentation. The resulting system of dynamic equations is of minimum dimension, and is suitable for numerical solution by computer. Implementation is ·discussed, and illustrative simulation results are presented.

  16. Dynamics on strata of trigonal Jacobians and some integrable problems of rigid body motion

    NASA Astrophysics Data System (ADS)

    Braden, H. W.; Enolski, V. Z.; Fedorov, Yu N.

    2013-07-01

    We present an algebraic geometrical and analytical description of the Goryachev case of rigid body motion. It belongs to a family of systems sharing the same properties: although completely integrable, they are not algebraically integrable, their solution is not meromorphic in the complex time and involves dynamics on the strata of the Jacobian varieties of trigonal curves. Although the strata of hyperelliptic Jacobians have already appeared in the literature in the context of some dynamical systems, the Goryachev case is the first example of an integrable system whose solution involves a more general curve. Several new features (and formulae) are encountered in the solution given in terms of sigma-functions of such a curve.

  17. On some approximations of the resultant contact forces and their applications in rigid body dynamics

    NASA Astrophysics Data System (ADS)

    Kudra, Grzegorz; Szewc, Michał; Wojtunik, Igor; Awrejcewicz, Jan

    2016-10-01

    The work presents the possible applications and effectiveness of certain class of models of the resultant friction force and rolling resistance. The friction models are based on the integral model constructed under assumption of fully developed sliding on the plane contact area of general shape and any pressure distribution. Then the integral model of friction force and moment are approximated based on Padé approximants and their generalizations. These models are expected to be computationally effective in numerical simulations of rigid bodies with frictional contacts, such like billiard balls, Thompson top, the wobble stone and many others. In the present work two different examples of application of the developed contact models are presented and tested: a) a billiard ball rolling and sliding on the plane horizontal table; b) a full ellipsoid of revolution in contact with plane and horizontal base.

  18. Symplectic integration of closed chain rigid body dynamics with internal coordinate equations of motion

    NASA Astrophysics Data System (ADS)

    Mazur, Alexey K.

    1999-07-01

    Internal coordinate molecular dynamics (ICMD) is a recent efficient method for modeling polymer molecules which treats them as chains of rigid bodies rather than ensembles of point particles as in Cartesian MD. Unfortunately, it is readily applicable only to linear or tree topologies without closed flexible loops. Important examples violating this condition are sugar rings of nucleic acids, proline residues in proteins, and also disulfide bridges. This paper presents the first complete numerical solution of the chain closure problem within the context of ICMD. The method combines natural implicit fixation of bond lengths and bond angles by the choice of internal coordinates with explicit constraints similar to Cartesian dynamics used to maintain the chain closure. It is affordable for large molecules and makes possible 3-5 times faster dynamics simulations of molecular systems with flexible rings, including important biological objects like nucleic acids and disulfide-bonded proteins.

  19. Unsteady transonic flow past airfoils in rigid-body motion. [UFLO5

    SciTech Connect

    Chang, I C

    1981-03-01

    With the aim of developing a fast and accurate computer code for predicting the aerodynamic forces needed for a flutter analysis, some basic concepts in computational transonics are reviewed. The unsteady transonic flow past airfoils in rigid body motion is adequately described by the potential flow equation as long as the boundary layer remains attached. The two dimensional unsteady transonic potential flow equation in quasilinear form with first order radiation boundary conditions is solved by an alternating direction implicit scheme in an airfoil attached sheared parabolic coordinate system. Numerical experiments show that the scheme is very stable and is able to resolve the higher nonlinear transonic effects for filter analysis within the context of an inviscid theory.

  20. Distributed event-triggered cooperative attitude control of multiple rigid bodies with leader-follower architecture

    NASA Astrophysics Data System (ADS)

    Weng, Shengxuan; Yue, Dong

    2016-02-01

    In this note, the distributed event-triggered cooperative attitude control of multiple rigid bodies with leader-follower architecture is investigated, where both the cases of static and dynamic leaders are all considered. Two distributed triggering procedures are first introduced for the followers and leaders, and then the distributed cooperative controllers are designed under the proposed triggering schemes. Under the designed controllers with the event-triggered strategies, it is shown that the orientations of followers converge to the convex hull formed by the desired leaders' orientations with zero angular velocities. Moreover, the communication pressure in network is reduced and the energy of each agent is saved. Simulation results show the effectiveness of the proposed method.

  1. In Silico Single-Molecule Manipulation of DNA with Rigid Body Dynamics

    PubMed Central

    Carrivain, Pascal; Barbi, Maria; Victor, Jean-Marc

    2014-01-01

    We develop a new powerful method to reproduce in silico single-molecule manipulation experiments. We demonstrate that flexible polymers such as DNA can be simulated using rigid body dynamics thanks to an original implementation of Langevin dynamics in an open source library called Open Dynamics Engine. We moreover implement a global thermostat which accelerates the simulation sampling by two orders of magnitude. We reproduce force-extension as well as rotation-extension curves of reference experimental studies. Finally, we extend the model to simulations where the control parameter is no longer the torsional strain but instead the torque, and predict the expected behavior for this case which is particularly challenging theoretically and experimentally. PMID:24586127

  2. Attitude dynamics simulation subroutines for systems of hinge-connected rigid bodies

    NASA Technical Reports Server (NTRS)

    Fleischer, G. E.; Likins, P. W.

    1974-01-01

    Several computer subroutines are designed to provide the solution to minimum-dimension sets of discrete-coordinate equations of motion for systems consisting of an arbitrary number of hinge-connected rigid bodies assembled in a tree topology. In particular, these routines may be applied to: (1) the case of completely unrestricted hinge rotations, (2) the totally linearized case (all system rotations are small), and (3) the mixed, or partially linearized, case. The use of the programs in each case is demonstrated using a five-body spacecraft and attitude control system configuration. The ability of the subroutines to accommodate prescribed motions of system bodies is also demonstrated. Complete listings and user instructions are included for these routines (written in FORTRAN V) which are intended as multi- and general-purpose tools in the simulation of spacecraft and other complex electromechanical systems.

  3. Free Energy Landscapes of Alanine Oligopeptides in Rigid-Body and Hybrid Water Models.

    PubMed

    Nayar, Divya; Chakravarty, Charusita

    2015-08-27

    Replica exchange molecular dynamics is used to study the effect of different rigid-body (mTIP3P, TIP4P, SPC/E) and hybrid (H1.56, H3.00) water models on the conformational free energy landscape of the alanine oligopeptides (acAnme and acA5nme), in conjunction with the CHARMM22 force field. The free energy landscape is mapped out as a function of the Ramachandran angles. In addition, various secondary structure metrics, solvation shell properties, and the number of peptide-solvent hydrogen bonds are monitored. Alanine dipeptide is found to have similar free energy landscapes in different solvent models, an insensitivity which may be due to the absence of possibilities for forming i-(i + 4) or i-(i + 3) intrapeptide hydrogen bonds. The pentapeptide, acA5nme, where there are three intrapeptide backbone hydrogen bonds, shows a conformational free energy landscape with a much greater degree of sensitivity to the choice of solvent model, though the three rigid-body water models differ only quantitatively. The pentapeptide prefers nonhelical, non-native PPII and β-sheet populations as the solvent is changed from SPC/E to the less tetrahedral liquid (H1.56) to an LJ-like liquid (H3.00). The pentapeptide conformational order metrics indicate a preference for open, solvent-exposed, non-native structures in hybrid solvent models at all temperatures of study. The possible correlations between the properties of solvent models and secondary structure preferences of alanine oligopeptides are discussed, and the competition between intrapeptide, peptide-solvent, and solvent-solvent hydrogen bonding is shown to be crucial in the relative free energies of different conformers.

  4. Horseshoes and Nonintegrability in the Restricted Case of a Spinless Axisymmetric Rigid Body in a Central Gravitational Field

    NASA Astrophysics Data System (ADS)

    Balan, Radu

    1995-03-01

    The purpose of this paper is to study the motion of a spinless axisymmetric rigid body in a Newtonian field when we suppose the motion of the center of mass of the rigid body is on a Keplerian orbit. In this case the system can be reduced to a Hamiltonian system with configuration space of a two-dimensional sphere. We prove that the restricted planar motion is analytical nonintegrable and we find horseshoes due to the eccentricity of the orbit. In the caseI 3/I 1>4/3, we prove that the system on the sphere is also analytical nonintegrable.

  5. Hamilton/Jacobi perturbation methods applied to the rotational motion of a rigid body in a gravitational field

    NASA Technical Reports Server (NTRS)

    Fitzpatrick, P. M.; Harmon, G. R.; Liu, J. J. F.; Cochran, J. E.

    1974-01-01

    The formalism for studying perturbations of a triaxial rigid body within the Hamilton-Jacobi framework is developed. The motion of a triaxial artificial earth satellite about its center of mass is studied. Variables are found which permit separation, and the Euler angles and associated conjugate momenta are obtained as functions of canonical constants and time.

  6. Studies of Global Stability of Fluid-reversed Configuration Plasmas using a Rigid Body Model

    SciTech Connect

    First Author = H. Ji; M. Yamada; R. Kulsrud; N. Pomphrey

    1998-04-01

    Global stability of field-reversed configuration (FRC) plasmas has been studied using a simple rigid body model in the parameter space ofs (ratio of separatrix radius to average ion gyroradius) and plasma elongation E (ratio of separatrix length to separatrix diameter). Tilt stability is predicted, independent of s, for FRC`s with low E(oblate), while the tilt stability of FRC`s with large E (prolate)depends on s/E. It is found that plasma rotation due to ion diamagnetic drift can stabilize the tilt mode when s/E is less than or equal to1.7. The so-called collisionless ion gyroviscosity also is identified to stabilize tilt when s/E is less than or equal to 2.2. Combining these two effects, the stability regime broadens to s/E is less than or equal to 2.8, consistent with previously developed theories. A small additional rotation (e.g., a Mach number of 0.2) can improve tilt stability significantly at large E. A similar approach is taken to study the physics of the shift stability. It is found that radial shift is unstable when E is < 1 WHILE AXIAL SHIFT IS UNSTABLE WHEN E is> 1. However, unlike tilt stability, gyroviscosity has little effect onshift stability.

  7. Fullrmc, a rigid body Reverse Monte Carlo modeling package enabled with machine learning and artificial intelligence.

    PubMed

    Aoun, Bachir

    2016-05-01

    A new Reverse Monte Carlo (RMC) package "fullrmc" for atomic or rigid body and molecular, amorphous, or crystalline materials is presented. fullrmc main purpose is to provide a fully modular, fast and flexible software, thoroughly documented, complex molecules enabled, written in a modern programming language (python, cython, C and C++ when performance is needed) and complying to modern programming practices. fullrmc approach in solving an atomic or molecular structure is different from existing RMC algorithms and software. In a nutshell, traditional RMC methods and software randomly adjust atom positions until the whole system has the greatest consistency with a set of experimental data. In contrast, fullrmc applies smart moves endorsed with reinforcement machine learning to groups of atoms. While fullrmc allows running traditional RMC modeling, the uniqueness of this approach resides in its ability to customize grouping atoms in any convenient way with no additional programming efforts and to apply smart and more physically meaningful moves to the defined groups of atoms. In addition, fullrmc provides a unique way with almost no additional computational cost to recur a group's selection, allowing the system to go out of local minimas by refining a group's position or exploring through and beyond not allowed positions and energy barriers the unrestricted three dimensional space around a group. PMID:26800289

  8. Generalized Predictive Control of Dynamic Systems with Rigid-Body Modes

    NASA Technical Reports Server (NTRS)

    Kvaternik, Raymond G.

    2013-01-01

    Numerical simulations to assess the effectiveness of Generalized Predictive Control (GPC) for active control of dynamic systems having rigid-body modes are presented. GPC is a linear, time-invariant, multi-input/multi-output predictive control method that uses an ARX model to characterize the system and to design the controller. Although the method can accommodate both embedded (implicit) and explicit feedforward paths for incorporation of disturbance effects, only the case of embedded feedforward in which the disturbances are assumed to be unknown is considered here. Results from numerical simulations using mathematical models of both a free-free three-degree-of-freedom mass-spring-dashpot system and the XV-15 tiltrotor research aircraft are presented. In regulation mode operation, which calls for zero system response in the presence of disturbances, the simulations showed reductions of nearly 100%. In tracking mode operations, where the system is commanded to follow a specified path, the GPC controllers produced the desired responses, even in the presence of disturbances.

  9. Fullrmc, a rigid body Reverse Monte Carlo modeling package enabled with machine learning and artificial intelligence.

    PubMed

    Aoun, Bachir

    2016-05-01

    A new Reverse Monte Carlo (RMC) package "fullrmc" for atomic or rigid body and molecular, amorphous, or crystalline materials is presented. fullrmc main purpose is to provide a fully modular, fast and flexible software, thoroughly documented, complex molecules enabled, written in a modern programming language (python, cython, C and C++ when performance is needed) and complying to modern programming practices. fullrmc approach in solving an atomic or molecular structure is different from existing RMC algorithms and software. In a nutshell, traditional RMC methods and software randomly adjust atom positions until the whole system has the greatest consistency with a set of experimental data. In contrast, fullrmc applies smart moves endorsed with reinforcement machine learning to groups of atoms. While fullrmc allows running traditional RMC modeling, the uniqueness of this approach resides in its ability to customize grouping atoms in any convenient way with no additional programming efforts and to apply smart and more physically meaningful moves to the defined groups of atoms. In addition, fullrmc provides a unique way with almost no additional computational cost to recur a group's selection, allowing the system to go out of local minimas by refining a group's position or exploring through and beyond not allowed positions and energy barriers the unrestricted three dimensional space around a group.

  10. Phase topology of one irreducible integrable problem in the dynamics of a rigid body

    NASA Astrophysics Data System (ADS)

    Ryabov, P. E.

    2013-08-01

    We consider the integrable system with three degrees of freedom for which V. V. Sokolov and A. V. Tsiganov specified the Lax pair. The Lax representation generalizes the L-A pair found by A. G. Reyman and M. A. Semenov-Tian-Shansky for the Kovalevskaya gyrostat in a double field. We give explicit formulas for the additional first integrals K and G (independent almost everywhere), which are functionally related to the coefficients of the spectral curve for the Sokolov-Tsiganov L-A pair. Using this form of the additional integrals K and G and the Kharlamov parametric reduction, we analytically present two invariant four-dimensional submanifolds where the induced dynamical system is Hamiltonian (almost everywhere) with two degrees of freedom. The system of equations specifying one of the invariant submanifolds is a generalization of the invariant relations for the integrable Bogoyavlensky case (rotation of a magnetized rigid body in homogeneous gravitational and magnetic fields). We use the method of critical subsystems to describe the phase topology of the whole system. For each subsystem, we construct the bifurcation diagrams and specify the bifurcations of the Liouville tori both inside the subsystems and in the whole system.

  11. Stiffness-generated rigid-body mode shapes for Lanczos eigensolution with SUPORT DOF by way of a MSC/NASTRAN DMAP alter

    NASA Technical Reports Server (NTRS)

    Abdallah, Ayman A.; Barnett, Alan R.; Widrick, Timothy W.; Manella, Richard T.; Miller, Robert P.

    1994-01-01

    When using all MSC/NASTRAN eigensolution methods except Lanczos, the analyst can replace the coupled system rigid-body modes calculated within DMAP module READ with mass orthogonalized and normalized rigid-body modes generated from the system stiffness. This option is invoked by defining MSC/NASTRAN r-set degrees of freedom via the SUPORT bulk data card. The newly calculated modes are required if the rigid-body modes calculated by the eigensolver are not 'clean' due to numerical roundoffs in the solution. When performing transient structural dynamic load analysis, the numerical roundoffs can result in inaccurate rigid-body accelerations which affect steady-state responses. Unfortunately, when using the Lanczos method and defining r-set degrees of freedom, the rigid-body modes calculated within DMAP module REIGL are retained. To overcome this limitation and to allow MSC/NASTRAN to handle SUPORT degrees of freedom identically for all eigensolvers, a DMAP Alter has been written which replaces Lanczos-calculated rigid-body modes with stiffness-generated rigid-body modes. The newly generated rigid-body modes are normalized with respect to the system mass and orthogonalized using the Gram-Schmidt technique. This algorithm has been implemented as an enhancement to an existing coupled loads methodology.

  12. A comparison of seven methods of within-subjects rigid-body pedobarographic image registration.

    PubMed

    Pataky, Todd C; Goulermas, John Y; Crompton, Robin H

    2008-10-20

    Image registration, the process of transforming images such that homologous structures optimally overlap, provides the pre-processing foundation for pixel-level functional image analysis. The purpose of this study was to compare the performances of seven methods of within-subjects pedobarographic image registration: (1) manual, (2) principal axes, (3) centre of pressure trajectory, (4) mean squared error, (5) probability-weighted variance, (6) mutual information, and (7) exclusive OR. We assumed that foot-contact geometry changes were negligibly small trial-to-trial and thus that a rigid-body transformation could yield optimum registration performance. Thirty image pairs were randomly selected from our laboratory database and were registered using each method. To compensate for inter-rater variability, the mean registration parameters across 10 raters were taken as representative of manual registration. Registration performance was assessed using four dissimilarity metrics (#4-7 above). One-way MANOVA found significant differences between the methods (p<0.001). Bonferroni post-hoc tests revealed that the centre of pressure method performed the poorest (p<0.001) and that the principal axes method tended to perform more poorly than remaining methods (p<0.070). Average manual registration was not different from the remaining methods (p=1.000). The results suggest that a variety of linear registration methods are appropriate for within-subjects pedobarographic images, and that manual image registration is a viable alternative to algorithmic registration when parameters are averaged across raters. The latter finding, in particular, may be useful for cases of image peculiarities resulting from outlier trials or from experimental manipulations that induce substantial changes in contact area or pressure profile geometry. PMID:18790481

  13. Curvilinear Immersed Boundary Method for Simulating Fluid Structure Interaction with Complex 3D Rigid Bodies

    PubMed Central

    Borazjani, Iman; Ge, Liang; Sotiropoulos, Fotis

    2010-01-01

    The sharp-interface CURVIB approach of Ge and Sotiropoulos [L. Ge, F. Sotiropoulos, A Numerical Method for Solving the 3D Unsteady Incompressible Navier-Stokes Equations in Curvilinear Domains with Complex Immersed Boundaries, Journal of Computational Physics 225 (2007) 1782–1809] is extended to simulate fluid structure interaction (FSI) problems involving complex 3D rigid bodies undergoing large structural displacements. The FSI solver adopts the partitioned FSI solution approach and both loose and strong coupling strategies are implemented. The interfaces between immersed bodies and the fluid are discretized with a Lagrangian grid and tracked with an explicit front-tracking approach. An efficient ray-tracing algorithm is developed to quickly identify the relationship between the background grid and the moving bodies. Numerical experiments are carried out for two FSI problems: vortex induced vibration of elastically mounted cylinders and flow through a bileaflet mechanical heart valve at physiologic conditions. For both cases the computed results are in excellent agreement with benchmark simulations and experimental measurements. The numerical experiments suggest that both the properties of the structure (mass, geometry) and the local flow conditions can play an important role in determining the stability of the FSI algorithm. Under certain conditions unconditionally unstable iteration schemes result even when strong coupling FSI is employed. For such cases, however, combining the strong-coupling iteration with under-relaxation in conjunction with the Aitken’s acceleration technique is shown to effectively resolve the stability problems. A theoretical analysis is presented to explain the findings of the numerical experiments. It is shown that the ratio of the added mass to the mass of the structure as well as the sign of the local time rate of change of the force or moment imparted on the structure by the fluid determine the stability and convergence of the

  14. A vector-dyadic development of the equations of motion for N-coupled rigid bodies and point masses

    NASA Technical Reports Server (NTRS)

    Frisch, H. P.

    1974-01-01

    The equations of motion are derived, in vector-dyadic format, for a topological tree of coupled rigid bodies, point masses, and symmetrical momentum wheels. These equations were programmed, and form the basis for the general-purpose digital computer program N-BOD. A complete derivation of the equations of motion is included along with a description of the methods used for kinematics, constraint elimination, and for the inclusion of nongyroscope forces and torques acting external or internal to the system.

  15. Vision-based control of holonomic robots for 3-dimensional rigid-body positioning using camera-space manipulation

    NASA Astrophysics Data System (ADS)

    Chen, Wenzong

    Camera-space manipulation was developed in this work for 3-dimensional 6-degree-of-freedom rigid-body positioning tasks with unknown work piece position and orientation. Using standard imaging devices and the very large GMF S-400 manipulator, highly precise manuever precision was achieved with negligible passive compliance. The maneuver succeeded consistently within a large range of work piece position and orientation provided the piece remained in the cameras' fields of view. The maneuver precision was further improved by accounting for the perspective effect in the camera-space locations of visually-detected cues painted on the objects to be positioned, using an iterative procedure that we devised in this work. The application of this procedure also increased the range of the work piece position and orientation within which the maneuver succeeded consistently. Also developed in this work was an iterative method for the estimation for grasp uncertainty in rigid-body positioning with camera-space manipulation. This added capability of camera-space manipulation allowed rigid-body positioning tasks to be accomplished with both unknown work piece position and orientation and unknown grasp.

  16. A stable fluid-structure-interaction solver for low-density rigid bodies using the immersed boundary projection method

    NASA Astrophysics Data System (ADS)

    Lācis, Uǧis; Taira, Kunihiko; Bagheri, Shervin

    2016-01-01

    Dispersion of low-density rigid particles with complex geometries is ubiquitous in both natural and industrial environments. We show that while explicit methods for coupling the incompressible Navier-Stokes equations and Newton's equations of motion are often sufficient to solve for the motion of cylindrical particles with low density ratios, for more complex particles - such as a body with a protrusion - they become unstable. We present an implicit formulation of the coupling between rigid body dynamics and fluid dynamics within the framework of the immersed boundary projection method. Similarly to previous work on this method, the resulting matrix equation in the present approach is solved using a block-LU decomposition. Each step of the block-LU decomposition is modified to incorporate the rigid body dynamics. We show that our method achieves second-order accuracy in space and first-order in time (third-order for practical settings), only with a small additional computational cost to the original method. Our implicit coupling yields stable solution for density ratios as low as 10-4. We also consider the influence of fictitious fluid located inside the rigid bodies on the accuracy and stability of our method.

  17. Multiple-Zone Diffractive Optic Element for Laser Ranging Applications

    NASA Technical Reports Server (NTRS)

    Ramos-Izquierdo, Luis A.

    2011-01-01

    A diffractive optic element (DOE) can be used as a beam splitter to generate multiple laser beams from a single input laser beam. This technology has been recently used in LRO s Lunar Orbiter Laser Altimeter (LOLA) instrument to generate five laser beams that measure the lunar topography from a 50-km nominal mapping orbit (see figure). An extension of this approach is to use a multiple-zone DOE to allow a laser altimeter instrument to operate over a wider range of distances. In particular, a multiple-zone DOE could be used for applications that require both mapping and landing on a planetary body. In this case, the laser altimeter operating range would need to extend from several hundred kilometers down to a few meters. The innovator was recently involved in an investigation how to modify the LOLA instrument for the OSIRIS asteroid mapping and sample return mission. One approach is to replace the DOE in the LOLA laser beam expander assembly with a multiple-zone DOE that would allow for the simultaneous illumination of the asteroid with mapping and landing laser beams. The proposed OSIRIS multiple-zone DOE would generate the same LOLA five-beam output pattern for high-altitude topographic mapping, but would simultaneously generate a wide divergence angle beam using a small portion of the total laser energy for the approach and landing portion of the mission. Only a few percent of the total laser energy is required for approach and landing operations as the return signal increases as the inverse square of the ranging height. A wide divergence beam could be implemented by making the center of the DOE a diffractive or refractive negative lens. The beam energy and beam divergence characteristics of a multiple-zone DOE could be easily tailored to meet the requirements of other missions that require laser ranging data. Current single-zone DOE lithographic manufacturing techniques could also be used to fabricate a multiple-zone DOE by masking the different DOE zones during

  18. An accuracy assessment of different rigid body image registration methods and robotic couch positional corrections using a novel phantom

    SciTech Connect

    Arumugam, Sankar; Xing Aitang; Jameson, Michael G.; Holloway, Lois

    2013-03-15

    Purpose: Image guided radiotherapy (IGRT) using cone beam computed tomography (CBCT) images greatly reduces interfractional patient positional uncertainties. An understanding of uncertainties in the IGRT process itself is essential to ensure appropriate use of this technology. The purpose of this study was to develop a phantom capable of assessing the accuracy of IGRT hardware and software including a 6 degrees of freedom patient positioning system and to investigate the accuracy of the Elekta XVI system in combination with the HexaPOD robotic treatment couch top. Methods: The constructed phantom enabled verification of the three automatic rigid body registrations (gray value, bone, seed) available in the Elekta XVI software and includes an adjustable mount that introduces known rotational offsets to the phantom from its reference position. Repeated positioning of the phantom was undertaken to assess phantom rotational accuracy. Using this phantom the accuracy of the XVI registration algorithms was assessed considering CBCT hardware factors and image resolution together with the residual error in the overall image guidance process when positional corrections were performed through the HexaPOD couch system. Results: The phantom positioning was found to be within 0.04 ({sigma}= 0.12) Degree-Sign , 0.02 ({sigma}= 0.13) Degree-Sign , and -0.03 ({sigma}= 0.06) Degree-Sign in X, Y, and Z directions, respectively, enabling assessment of IGRT with a 6 degrees of freedom patient positioning system. The gray value registration algorithm showed the least error in calculated offsets with maximum mean difference of -0.2({sigma}= 0.4) mm in translational and -0.1({sigma}= 0.1) Degree-Sign in rotational directions for all image resolutions. Bone and seed registration were found to be sensitive to CBCT image resolution. Seed registration was found to be most sensitive demonstrating a maximum mean error of -0.3({sigma}= 0.9) mm and -1.4({sigma}= 1.7) Degree-Sign in translational

  19. General Relativistic Elastic Body, Fluid,quasi-rigid Body, Quasi-liquid and Others in Multiple Coordinate Systems

    NASA Astrophysics Data System (ADS)

    Xu, Chongming

    2009-05-01

    The approximation method in multiple coordinate systems at first post Newtonian (1 PN) level has been established by Darmour, Soffel and Xu (Phys. Rev. D(PRD) 43, 3273 (1991);D 45, 1017(1992);D 47, 3124 (1993);D 49, 618 (1994)). Normally, to discuss an astronomical object (e.g. a star in binary systems or the earth in solar system) we need multiple coordinate systems, especially for precise astrometry 1 PN (some time even 2 PN) approximate method is required. As we know up to now the ideas on elastic body, fluid, rigid body and liquid in the framework of Newtonian physics are still very useful for understanding and calculating some practical problems. Although the general relativistic theories of elastic body, general relativistic hydrodynamics and post-Newtonian quasi-rigid body have been discussed by many authors (including our papers (PRD63, 043002(2001); D63, 064001(2001); D68, 064009(2003); D69, 024003(2004); D71,024030 (2005))), but there is no completing discussion on all of these ideas in a unified point view. The applications of these ideas in the general relativity are important in the research fields of astrometry and geophysics, especially in case precise measurements reach so higher level (millimicro arc sec). The extended relativistic versions of these ideas should be revised the Newtonian results. In this paper, we shall give a complete discussion on all of these ideas in 1 PN approximation. We shall clarify the ideas on perfect elastic material, quasi-rigid body, quasi-liquid and so on with some precise mathematical forms. For fluid we show the hydrodynamic equations of a non-perfect fluid in multiple coordinates systems (both local and global).

  20. Computer program for post-flight analysis of rigid body moments acting on a launch vehicle first stage

    NASA Technical Reports Server (NTRS)

    Knauber, R. N.

    1982-01-01

    A FORTRAN coded computer program and method for evaluation of the rigid body disturbing moments for a launch vehicle first stage based on post-flight measurements is described. The technique is a straightforward deterministic approach. Residual moments are computed to satisfy the equations of motion. Residuals are expressed in terms of altered vehicle characteristics; the aerodynamic coefficients, thrust misalignment, and control effectiveness. This method was used on the Scout launch vehicle and uncovered several significant differences between flight data and wind tunnel data. The computer program is written in FORTRAN IV for a CDC CYBER 173 computer system.

  1. Newton's problems with rigid body dynamics in the light of his treatment of the precession of the equinoxes.

    NASA Astrophysics Data System (ADS)

    Dobson, G. J.

    1998-07-01

    Newton's treatment of the precession of the equinoxes in his Philosophiae Naturalis Principia Mathematica was recognised by d'Alembert in 1749 as being faulty, despite the very close agreement between Newton's calculated value for the rate of precesion and the observed value. Here, the author presents an analysis of Newton's geometrical methods applied in his treatment of precession and claims that it was basically flawed because Newton lacked knowledge of the principles of rigid body dynamics and, in particular, was unaware of the idea of angular momentum.

  2. AUTOMATISM.

    PubMed

    MCCALDON, R J

    1964-10-24

    Individuals can carry out complex activity while in a state of impaired consciousness, a condition termed "automatism". Consciousness must be considered from both an organic and a psychological aspect, because impairment of consciousness may occur in both ways. Automatism may be classified as normal (hypnosis), organic (temporal lobe epilepsy), psychogenic (dissociative fugue) or feigned. Often painstaking clinical investigation is necessary to clarify the diagnosis. There is legal precedent for assuming that all crimes must embody both consciousness and will. Jurists are loath to apply this principle without reservation, as this would necessitate acquittal and release of potentially dangerous individuals. However, with the sole exception of the defence of insanity, there is at present no legislation to prohibit release without further investigation of anyone acquitted of a crime on the grounds of "automatism".

  3. Numerical model (switchable/dual model) of the human head for rigid body and finite elements applications.

    PubMed

    Tabacu, Stefan

    2015-01-01

    In this paper, a methodology for the development and validation of a numerical model of the human head using generic procedures is presented. All steps required, starting with the model generation, model validation and applications will be discussed. The proposed model may be considered as a dual one due to its capabilities to switch from deformable to a rigid body according to the application's requirements. The first step is to generate the numerical model of the human head using geometry files or medical images. The required stiffness and damping for the elastic connection used for the rigid body model are identified by performing a natural frequency analysis. The presented applications for model validation are related to impact analysis. The first case is related to Nahum's (Nahum and Smith 1970) experiments pressure data being evaluated and a pressure map generated using the results from discrete elements. For the second case, the relative displacement between the brain and the skull is evaluated according to Hardy's (Hardy WH, Foster CD, Mason, MJ, Yang KH, King A, Tashman S. 2001.Investigation of head injury mechanisms using neutral density technology and high-speed biplanar X-ray. Stapp Car Crash J. 45:337-368, SAE Paper 2001-22-0016) experiments. The main objective is to validate the rigid model as a quick and versatile tool for acquiring the input data for specific brain analyses. PMID:24156633

  4. Stability of the Triangular Libration Points in the Unrestricted Planar Problem of a Symmetric Rigid Body and a Point Mass

    NASA Astrophysics Data System (ADS)

    Goździewski, Krzysztof

    2003-01-01

    In papers (Goździewski and Maciejewski, 1998a, b, 1999), we investigate unrestricted, planar problem of a dynamically symmetric rigid body and a sphere. Following the original statement of the problem by Kokoriev and Kirpichnikov (1988), we assume that the potential of the rigid body is approximated by the gravitational field of a dumb-bell. The model is described in terms of a 2D Hamiltonian depending on three parameters. In this paper, we investigate the stability of triangular equilibria permissible by the dynamics of the model, under the assumption of low-order resonances. We analyze all resonances of order smaller than four, and we examine the stability with application of theorems by Markeev and Sokolsky. These are the possible following cases: the non-diagonal resonance of the first order with two null characteristic frequencies (unstable); resonances of the first order with one nonzero frequency (diagonal and non-diagonal, stable and unstable); the second-order resonance, which is non-diagonal and stable, and the third-order resonance which is generically unstable, except for three points in the parameters' space, corresponding to stable equilibria. We discuss a perturbed version of Kokoriev and Kirpichnikov model, and we find that if the perturbation is small and depends on the coordinates only, the triangular equilibria persist, except if for the unperturbed equilibria the first-order resonance occurs. We show that the resonances of the order higher than two are also preserved if the perturbation acts.

  5. Numerical model (switchable/dual model) of the human head for rigid body and finite elements applications.

    PubMed

    Tabacu, Stefan

    2015-01-01

    In this paper, a methodology for the development and validation of a numerical model of the human head using generic procedures is presented. All steps required, starting with the model generation, model validation and applications will be discussed. The proposed model may be considered as a dual one due to its capabilities to switch from deformable to a rigid body according to the application's requirements. The first step is to generate the numerical model of the human head using geometry files or medical images. The required stiffness and damping for the elastic connection used for the rigid body model are identified by performing a natural frequency analysis. The presented applications for model validation are related to impact analysis. The first case is related to Nahum's (Nahum and Smith 1970) experiments pressure data being evaluated and a pressure map generated using the results from discrete elements. For the second case, the relative displacement between the brain and the skull is evaluated according to Hardy's (Hardy WH, Foster CD, Mason, MJ, Yang KH, King A, Tashman S. 2001.Investigation of head injury mechanisms using neutral density technology and high-speed biplanar X-ray. Stapp Car Crash J. 45:337-368, SAE Paper 2001-22-0016) experiments. The main objective is to validate the rigid model as a quick and versatile tool for acquiring the input data for specific brain analyses.

  6. Deformable registration for image-guided spine surgery: preserving rigid body vertebral morphology in free-form transformations

    NASA Astrophysics Data System (ADS)

    Reaungamornrat, S.; Wang, A. S.; Uneri, A.; Otake, Y.; Zhao, Z.; Khanna, A. J.; Siewerdsen, J. H.

    2014-03-01

    Purpose: Deformable registration of preoperative and intraoperative images facilitates accurate localization of target and critical anatomy in image-guided spine surgery. However, conventional deformable registration fails to preserve the morphology of rigid bone anatomy and can impart distortions that confound high-precision intervention. We propose a constrained registration method that preserves rigid morphology while allowing deformation of surrounding soft tissues. Method: The registration method aligns preoperative 3D CT to intraoperative cone-beam CT (CBCT) using free-form deformation (FFD) with penalties on rigid body motion imposed according to a simple intensity threshold. The penalties enforced 3 properties of a rigid transformation - namely, constraints on affinity (AC), orthogonality (OC), and properness (PC). The method also incorporated an injectivity constraint (IC) to preserve topology. Physical experiments (involving phantoms, an ovine spine, and a human cadaver) as well as digital simulations were performed to evaluate the sensitivity to registration parameters, preservation of rigid body morphology, and overall registration accuracy of constrained FFD in comparison to conventional unconstrained FFD (denoted uFFD) and Demons registration. Result: FFD with orthogonality and injectivity constraints (denoted FFD+OC+IC) demonstrated improved performance compared to uFFD and Demons. Affinity and properness constraints offered little or no additional improvement. The FFD+OC+IC method preserved rigid body morphology at near-ideal values of zero dilatation (D = 0.05, compared to 0.39 and 0.56 for uFFD and Demons, respectively) and shear (S = 0.08, compared to 0.36 and 0.44 for uFFD and Demons, respectively). Target registration error (TRE) was similarly improved for FFD+OC+IC (0.7 mm), compared to 1.4 and 1.8 mm for uFFD and Demons. Results were validated in human cadaver studies using CT and CBCT images, with FFD+OC+IC providing excellent preservation

  7. mtsslSuite: In silico spin labelling, trilateration and distance-constrained rigid body docking in PyMOL

    NASA Astrophysics Data System (ADS)

    Hagelueken, Gregor; Abdullin, Dinar; Ward, Richard; Schiemann, Olav

    2013-10-01

    Nanometer distance measurements based on electron paramagnetic resonance methods in combination with site-directed spin labelling are powerful tools for the structural analysis of macromolecules. The software package mtsslSuite provides scientists with a set of tools for the translation of experimental distance distributions into structural information. The package is based on the previously published mtsslWizard software for in silico spin labelling. The mtsslSuite includes a new version of MtsslWizard that has improved performance and now includes additional types of spin labels. Moreover, it contains applications for the trilateration of paramagnetic centres in biomolecules and for rigid-body docking of subdomains of macromolecular complexes. The mtsslSuite is tested on a number of challenging test cases and its strengths and weaknesses are evaluated.

  8. A variational formulation with rigid-body constraints for finite elasticity: theory, finite element implementation, and applications

    NASA Astrophysics Data System (ADS)

    Chi, Heng; Lopez-Pamies, Oscar; Paulino, Glaucio H.

    2016-02-01

    This paper presents a new variational principle in finite elastostatics applicable to arbitrary elastic solids that may contain constitutively rigid spatial domains (e.g., rigid inclusions). The basic idea consists in describing the constitutive rigid behavior of a given spatial domain as a set of kinematic constraints over the boundary of the domain. From a computational perspective, the proposed formulation is shown to reduce to a set of algebraic constraints that can be implemented efficiently in terms of both single-field and mixed finite elements of arbitrary order. For demonstration purposes, applications of the proposed rigid-body-constraint formulation are illustrated within the context of elastomers, reinforced with periodic and random distributions of rigid filler particles, undergoing finite deformations.

  9. Automatism

    PubMed Central

    McCaldon, R. J.

    1964-01-01

    Individuals can carry out complex activity while in a state of impaired consciousness, a condition termed “automatism”. Consciousness must be considered from both an organic and a psychological aspect, because impairment of consciousness may occur in both ways. Automatism may be classified as normal (hypnosis), organic (temporal lobe epilepsy), psychogenic (dissociative fugue) or feigned. Often painstaking clinical investigation is necessary to clarify the diagnosis. There is legal precedent for assuming that all crimes must embody both consciousness and will. Jurists are loath to apply this principle without reservation, as this would necessitate acquittal and release of potentially dangerous individuals. However, with the sole exception of the defence of insanity, there is at present no legislation to prohibit release without further investigation of anyone acquitted of a crime on the grounds of “automatism”. PMID:14199824

  10. Using Conjoined Rigid Body/Torsion Angle Simulated Annealing to Determine the Relative Orientation of Covalently Linked Protein Domains from Dipolar Couplings

    NASA Astrophysics Data System (ADS)

    Clore, G. Marius; Bewley, Carole A.

    2002-02-01

    A simple and robust method for determining the relative orientations of covalently linked protein domains using conjoined rigid body/torsion angle dynamics simulated annealing on the basis of residual dipolar couplings is presented. In this approach each domain is treated as a rigid body and the relevant degrees of conformational freedom are restricted to the backbone torsion angles (φ, ψ) of the linker between the domains. By this means translational information afforded by the presence of an intact linker is preserved. We illustrate this approach using the domain-swapped dimer of the HIV-inactivating protein cyanovirin-N as an example.

  11. An improved understanding of the natural resonances of moonpools contained within floating rigid-bodies: Theory and application to oscillating water column devices

    SciTech Connect

    Bull, Diana L.

    2015-09-23

    The fundamental interactions between waves, a floating rigid-body, and a moonpool that is selectively open to atmosphere or enclosed to purposefully induce pressure fluctuations are investigated. The moonpool hydrodynamic characteristics and the hydrodynamic coupling to the rigid-body are derived implicitly through reciprocity relations on an array of field points. By modeling the free surface of the moonpool in this manner, an explicit hydrodynamic coupling term is included in the equations of motion. This coupling results in the migration of the moonpool's natural resonance frequency from the piston frequency to a new frequency when enclosed in a floating rigid-body. Two geometries that highlight distinct aspects of marine vessels and oscillating water column (OWC) renewable energy devices are analyzed to reveal the coupled natural resonance migration. The power performance of these two OWCs in regular waves is also investigated. The air chamber is enclosed and a three-dimensional, linear, frequency domain performance model that links the rigid-body to the moonpool through a linear resistive control strategy is detailed. Furthermore, an analytic expression for the optimal linear resistive control values in regular waves is presented.

  12. Analogies between the Torque-Free Motion of a Rigid Body about a Fixed Point and Light Propagation in Anisotropic Media

    ERIC Educational Resources Information Center

    Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo

    2009-01-01

    An apparently unnoticed analogy between the torque-free motion of a rotating rigid body about a fixed point and the propagation of light in anisotropic media is stated. First, a new plane construction for visualizing this torque-free motion is proposed. This method uses an intrinsic representation alternative to angular momentum and independent of…

  13. An improved understanding of the natural resonances of moonpools contained within floating rigid-bodies: Theory and application to oscillating water column devices

    DOE PAGES

    Bull, Diana L.

    2015-09-23

    The fundamental interactions between waves, a floating rigid-body, and a moonpool that is selectively open to atmosphere or enclosed to purposefully induce pressure fluctuations are investigated. The moonpool hydrodynamic characteristics and the hydrodynamic coupling to the rigid-body are derived implicitly through reciprocity relations on an array of field points. By modeling the free surface of the moonpool in this manner, an explicit hydrodynamic coupling term is included in the equations of motion. This coupling results in the migration of the moonpool's natural resonance frequency from the piston frequency to a new frequency when enclosed in a floating rigid-body. Two geometriesmore » that highlight distinct aspects of marine vessels and oscillating water column (OWC) renewable energy devices are analyzed to reveal the coupled natural resonance migration. The power performance of these two OWCs in regular waves is also investigated. The air chamber is enclosed and a three-dimensional, linear, frequency domain performance model that links the rigid-body to the moonpool through a linear resistive control strategy is detailed. Furthermore, an analytic expression for the optimal linear resistive control values in regular waves is presented.« less

  14. Comparison between single and multi-camera view videogrammetry for estimating 6DOF of a rigid body

    NASA Astrophysics Data System (ADS)

    Nocerino, Erica; Menna, Fabio; Remondino, Fabio

    2015-05-01

    Motion capture (MOCAP) systems are used in many fields of application (e.g., machine vision, navigation, industrial measurements, medicine) for tracking and measuring the 6DOF (Degrees-Of-Freedom) of bodies. A variety of systems has been developed in the commercial, as well as research domain, exploiting different sensors and techniques, among which optical methods, based on multi-epoch photogrammetry, are the most common. The authors have developed an off-line low-cost MOCAP system made up of three consumer-grade video cameras, i.e. a multi-view camera system. The system was employed in two different case studies for measuring the motion of personnel working onboard a fishing boat and of a ship model in a towing tank (or model basin) subjected to different sea conditions. In this contribution, the same three single cameras are separately processed to evaluate the performances of a sequential space resection method for estimated the 6DOF of a rigid body (a ship model during high frequency tests in a model basin). The results from each video camera are compared with the motion estimated using the multi-view approach, with the aim of providing a quantitative assessment of the performances obtainable.

  15. A heterogeneous system based on GPU and multi-core CPU for real-time fluid and rigid body simulation

    NASA Astrophysics Data System (ADS)

    da Silva Junior, José Ricardo; Gonzalez Clua, Esteban W.; Montenegro, Anselmo; Lage, Marcos; Dreux, Marcelo de Andrade; Joselli, Mark; Pagliosa, Paulo A.; Kuryla, Christine Lucille

    2012-03-01

    Computational fluid dynamics in simulation has become an important field not only for physics and engineering areas but also for simulation, computer graphics, virtual reality and even video game development. Many efficient models have been developed over the years, but when many contact interactions must be processed, most models present difficulties or cannot achieve real-time results when executed. The advent of parallel computing has enabled the development of many strategies for accelerating the simulations. Our work proposes a new system which uses some successful algorithms already proposed, as well as a data structure organisation based on a heterogeneous architecture using CPUs and GPUs, in order to process the simulation of the interaction of fluids and rigid bodies. This successfully results in a two-way interaction between them and their surrounding objects. As far as we know, this is the first work that presents a computational collaborative environment which makes use of two different paradigms of hardware architecture for this specific kind of problem. Since our method achieves real-time results, it is suitable for virtual reality, simulation and video game fluid simulation problems.

  16. Update of diagnostic preoperative images using low-field interventional MRI for navigation in neurosurgery: rigid-body registration

    NASA Astrophysics Data System (ADS)

    Kavec, Martin; Wikler, David; Phillips, Christophe L. M.; Vigneron, Lara M.; Levivier, Marc; Verly, Jacques G.

    2005-04-01

    This study looks into the rigid-body registration of pre-operative anatomical high field and interventional low field magnetic resonance images (MRI). The accurate 3D registration of these modalities is required to enhance the content of interventional images with anatomical (CT, high field MRI, DTI), functional (DWI, fMRI, PWI), metabolic (PET) or angiography (CTA, MRA) pre-operative images. The specific design of the interventional MRI scanner used in the present study, a PoleStar N20, induces image artifacts, such as ellipsoidal masking and intensity inhomogeneities, which affect registration performance. On MRI data from eleven patients, who underwent resection of a brain tumor, we quantitatively evaluated the effects of artifacts in the image registration process based on a normalized mutual information (NMI) metric criterion. The results show that the quality of alignment of pre-operative anatomical and interventional images strongly depends on pre-processing carried out prior to registration. The registration results scored the highest in visual evaluation only if intensity variations and masking were considered in image registration. We conclude that the alignment of anatomical high field MRI and PoleStar interventional images is the most accurate when the PoleStar's induced image artifacts are corrected for before registration.

  17. Governing equations of multi-component rigid body-spring discrete element models of reinforced concrete columns

    NASA Astrophysics Data System (ADS)

    Guan, P. B.; Tingatinga, E. A.; Longalong, R. E.; Saguid, J.

    2016-09-01

    During the past decades, the complexity of conventional methods to perform seismic performance assessment of buildings led to the development of more effective approaches. The rigid body spring-discrete element method (RBS-DEM) is one of these approaches and has recently been applied to the study of the behavior of reinforced concrete (RC) buildings subjected to strong earthquakes. In this paper, the governing equations of RBS-DEM planar elements subjected to lateral loads and horizontal ground motion are presented and used to replicate the hysteretic behavior of experimental RC columns. The RBS-DEM models of columns are made up of rigid components connected by systems of springs that simulate axial, shear, and bending behavior of an RC section. The parameters of springs were obtained using Response-2000 software and the hysteretic response of the models of select columns from the Pacific Earthquake Engineering Research (PEER) Structural Performance Database were computed numerically. Numerical examples show that one-component models were able to simulate the initial stiffness reasonably, while the displacement capacity of actual columns undergoing large displacements were underestimated.

  18. The planar restricted three-body problem when both primaries are triaxial rigid bodies: Equilibrium points and periodic orbits

    NASA Astrophysics Data System (ADS)

    Elshaboury, S. M.; Abouelmagd, Elbaz I.; Kalantonis, V. S.; Perdios, E. A.

    2016-09-01

    The restricted three-body problem when the primaries are triaxial rigid bodies is considered and its basic dynamical features are studied. In particular, the equilibrium points are identified as well as their stability is determined in the special case when the Euler angles of rotational motion are accordingly θi = ψi = π/2 and φi = π/2, i = 1, 2. It is found that three unstable collinear equilibrium points exist and two triangular such points which may be stable. Special attention has also been paid to the study of simple symmetric periodic orbits and 31 families consisting of such orbits have been determined. It has been found that only one of these families consists entirely of unstable members while the remaining families contain stable parts indicating that other families bifurcate from them. Finally, using the grid-search technique a global solution in the space of initial conditions is obtained which comprises simple and of higher multiplicities symmetric periodic orbits as well as escape and collision orbits.

  19. Estimation of Rigid-Body and Respiratory Motion of the Heart From Marker-Tracking Data for SPECT Motion Correction

    PubMed Central

    Mukherjee, Joyeeta Mitra; McNamara, Joseph E.; Johnson, Karen L.; Dey, Joyoni; King, Michael A.

    2009-01-01

    Motion of patients undergoing cardiac SPECT perfusion imaging causes artifacts in the acquired images which may lead to difficulty in interpretation. Our work investigates a technique of obtaining patient motion estimates from retro-reflective markers on stretchy bands wrapped around the chest and abdomen of patients being imaged clinically. Motion signals obtained from the markers consist of at least two components, body motion (BM) and periodic motion (PM) due to respiration. We present a method for separating these components from the motion-tracking data of each marker, and then report a method for combining the BM estimated from chest markers to estimate the 6-degree-of-freedom (6-DOF) rigid-body motion (RBM) of the heart. Motion studies of volunteers and patients are used to evaluate the methods. Illustrative examples of the motion of the heart due to patient body movement and respiration (upward creep) are presented and compared to estimates of the motion of the heart obtained directly from SPECT data. Our motion-tracking method is seen to give reasonable agreement with the motion-estimates from the SPECT data while being considerably less noisy. PMID:20539825

  20. Application of rigid body mechanics to theoretical description of rotation within F0F1-ATP synthase.

    PubMed

    Nartsissov, Yaroslav R; Mashkovtseva, Elena V

    2006-09-21

    ATP synthase catalyses the formation of ATP from ADP and P(i) and is powered by the diffusion of protons throughout membranes down the proton electrochemical gradient. The protein consists of a water-soluble F(1) and a transmembrane F(0) proton transporter part. It was previously shown that the ring of membrane subunits rotates past a fixed subunit during catalytic cycle of the enzyme. However, many parameters of this movement are still unknown. In the present study the mutual protein movement in the membrane part of F(0)F(1)-ATP syntase has been analysed within the framework of rigid body mechanics. On the base of available experimental data it was shown that electrostatic interaction of two charged amino acids residues is able to supply quite enough energy for the rotation. The initial torque, which caused the rotation, was estimated as 3.7 pN nm and for this pattern the angular movement of c subunits complex could not physically have a period less than 10(-9)s. If membrane viscosity and elastic resistance were taken into account then the time of a whole turnover could rise up to 6.3 x 10(-3)s. It is remarkable that rotation will take place only under condition when the elasticity (Young's) module of the central stalk (gamma subunit and other minor subunits) is less than 5.0 x 10(7)N/m(2). Thus, for generally accepted structural parameters of ATP synthase, two-charge electrostatic interaction model does not permit rotation of the rotor if elastic properties of the central stalk are tougher than mentioned above. In order to explain the rotation under that condition one should either suppose a shorter distance between subunit a and c subunits complex or assume interaction of more than two charged amino acids residues.

  1. A topological classification of the Chaplygin systems in the dynamics of a rigid body in a fluid

    SciTech Connect

    Nikolaenko, S S

    2014-02-28

    The paper is concerned with the topological analysis of the Chaplygin integrable case in the dynamics of a rigid body in a fluid. A full list of the topological types of Chaplygin systems in their dependence on the energy level is compiled on the basis of the Fomenko-Zieschang theory. An effective description of the topology of the Liouville foliation in terms of natural coordinate variables is also presented, which opens a direct way to calculating topological invariants. It turns out that on all nonsingular energy levels Chaplygin systems are Liouville equivalent to the well-known Euler case in the dynamics of a rigid body with fixed point. Bibliography: 23 titles.

  2. Conditions for the existence of the asymptotically pendulum motions of a rigid body with the center of mass on the main axis

    NASA Astrophysics Data System (ADS)

    Varkhalev, Iu. P.

    1988-07-01

    The first Liapunov method is used to investigate sufficient conditions for the existence of asymptotically pendulum motions of a rigid body with a single fixed point. A region of permissible values of the parameters characterizing the body mass corresponding to the asymptotically pendulum motions is defined. The existence of such motions in the case of the Kovalevskii solution and their absence in the Goriachev-Chapolygin solution are demonstrated.

  3. A review of a method for dynamic load distribution, dynamical modeling, and explicit internal force control when two manipulators mutually lift and transport a rigid body object

    SciTech Connect

    Unseren, M.A.

    1997-04-20

    The paper reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restrict the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system.

  4. Representation of solutions to the problem of the motion of a heavy rigid body in the Kovalevskaya case in terms of Weierstrass \\zeta- and \\wp-functions and nonintegrability of the Hess case by quadratures

    NASA Astrophysics Data System (ADS)

    Belyaev, A. V.

    2016-07-01

    A method for the representation of Delaunay's solutions and some other particular solutions to the problem of the motion of a heavy rigid body in the Kovalevskaya case in terms of the Weierstrass \\zeta- and \\wp-functions is put forward. The Hess case in the problem of the motion of a heavy rigid body is shown to be nonintegrable by quadratures. Bibliography: 24 titles.

  5. Further comments on the application of the method of averaging to the study of the rotational motions of a triaxial rigid body, part 3

    NASA Technical Reports Server (NTRS)

    Liu, J. J. F.; Fitzpatrick, P. M.

    1973-01-01

    Variational equations were applied to the case of a rapidly spinning triaxial body moving in an elliptic orbit, in which the orbital plane is regressing at a constant rate. The explicit differential equations obtained in this application were integrated by the method of averaging to develop secular analytical expressions, which, to first-order in a small parameter, describe the complete space motions of the rigid body under the influence of nonresonant gravity-gradient perturbations. The effects of aerodynamic torque on the rotational motion of an orbiting satellite are studied, as another example of the application of the variational equations derived and the method of averaging.

  6. Comparison of Efficency of Translation Between a Deformable Swimmer Versus a Rigid Body in a Bounded Fluid Domain: Consequences for Subcellular Transport

    PubMed Central

    González-García, José S.

    2006-01-01

    In this paper, we compare the translation efficiencies of a deformable circle that swims by means of low amplitude periodic tangential surface waves versus a rigid circle, moving in a bounded fluid domain. The swimmer is found to be much more efficient than the rigid body. We believe that this result gives some support to the active hypothesis of subcellular transport, where it is supposed that the organelle can generate by itself a propulsive flux, (by changes of form or metabolic activities) instead of just being carried by the motion of an external agent, like a molecular motor. PMID:19669454

  7. Multiple zone coal degasification potential in the Warrior coal field of Alabama

    SciTech Connect

    Graves, S.L.; Beavers, W.M.; Patton, A.

    1982-01-01

    The Upper Pottsville formation in the Warrior Coal Field of Alabama has six recognized groups of bituminous coal seams. Three of these groups, the Pratt, Mary Lee, and Black Creek consist of seams containing commercially significant quantities of methane. In parts of the Warrior Coal Field, where all three groups can be penetrated in one vertical borehole, the potential production from multiple zone completion wells can result in commercially profitable wells. Various open hole and through the casing completion procedures are being applied resulting in successful methane production from these multiple zone coal gas wells.

  8. Transport properties of rigid bent-rod macromolecules and of semiflexible broken rods in the rigid-body treatment. Analysis of the flexibility of myosin rod.

    PubMed Central

    Iniesta, A; Díaz, F G; García de la Torre, J

    1988-01-01

    The translational diffusion coefficients, rotational relaxation times and intrinsic viscosities of rigid bent rods, composed by two rodlike arms joined rigidly at an angle alpha, have been evaluated for varying conformation using the latest advances in hydrodynamic theory. We have considered semiflexible rods in which the joint is an elastic hinge or swivel, with a potential V(alpha) = 1/2Q alpha 2 with constant Q. Accepting the rigid-body treatment, we calculate properties of broken rods by averaging alpha-dependent values for rigid rods. The results are finally used to interpret literature values of the properties of myosin rod. Q is regarded as an adjustable parameter, and the value fitted is such that the average bending angle of myosin rod is approximately 60 degrees. PMID:3207825

  9. Improved Accuracy in RNA-Protein Rigid Body Docking by Incorporating Force Field for Molecular Dynamics Simulation into the Scoring Function.

    PubMed

    Iwakiri, Junichi; Hamada, Michiaki; Asai, Kiyoshi; Kameda, Tomoshi

    2016-09-13

    RNA-protein interactions play fundamental roles in many biological processes. To understand these interactions, it is necessary to know the three-dimensional structures of RNA-protein complexes. However, determining the tertiary structure of these complexes is often difficult, suggesting that an accurate rigid body docking for RNA-protein complexes is needed. In general, the rigid body docking process is divided into two steps: generating candidate structures from the individual RNA and protein structures and then narrowing down the candidates. In this study, we focus on the former problem to improve the prediction accuracy in RNA-protein docking. Our method is based on the integration of physicochemical information about RNA into ZDOCK, which is known as one of the most successful computer programs for protein-protein docking. Because recent studies showed the current force field for molecular dynamics simulation of protein and nucleic acids is quite accurate, we modeled the physicochemical information about RNA by force fields such as AMBER and CHARMM. A comprehensive benchmark of RNA-protein docking, using three recently developed data sets, reveals the remarkable prediction accuracy of the proposed method compared with existing programs for docking: the highest success rate is 34.7% for the predicted structure of the RNA-protein complex with the best score and 79.2% for 3,600 predicted ones. Three full atomistic force fields for RNA (AMBER94, AMBER99, and CHARMM22) produced almost the same accurate result, which showed current force fields for nucleic acids are quite accurate. In addition, we found that the electrostatic interaction and the representation of shape complementary between protein and RNA plays the important roles for accurate prediction of the native structures of RNA-protein complexes.

  10. Creation of 3D digital anthropomorphic phantoms which model actual patient non-rigid body motion as determined from MRI and position tracking studies of volunteers

    NASA Astrophysics Data System (ADS)

    Connolly, C. M.; Konik, A.; Dasari, P. K. R.; Segars, P.; Zheng, S.; Johnson, K. L.; Dey, J.; King, M. A.

    2011-03-01

    Patient motion can cause artifacts, which can lead to difficulty in interpretation. The purpose of this study is to create 3D digital anthropomorphic phantoms which model the location of the structures of the chest and upper abdomen of human volunteers undergoing a series of clinically relevant motions. The 3D anatomy is modeled using the XCAT phantom and based on MRI studies. The NURBS surfaces of the XCAT are interactively adapted to fit the MRI studies. A detailed XCAT phantom is first developed from an EKG triggered Navigator acquisition composed of sagittal slices with a 3 x 3 x 3 mm voxel dimension. Rigid body motion states are then acquired at breath-hold as sagittal slices partially covering the thorax, centered on the heart, with 9 mm gaps between them. For non-rigid body motion requiring greater sampling, modified Navigator sequences covering the entire thorax with 3 mm gaps between slices are obtained. The structures of the initial XCAT are then adapted to fit these different motion states. Simultaneous to MRI imaging the positions of multiple reflective markers on stretchy bands about the volunteer's chest and abdomen are optically tracked in 3D via stereo imaging. These phantoms with combined position tracking will be used to investigate both imaging-data-driven and motion-tracking strategies to estimate and correct for patient motion. Our initial application will be to cardiacperfusion SPECT imaging where the XCAT phantoms will be used to create patient activity and attenuation distributions for each volunteer with corresponding motion tracking data from the markers on the body-surface. Monte Carlo methods will then be used to simulate SPECT acquisitions, which will be used to evaluate various motion estimation and correction strategies.

  11. Improved Accuracy in RNA-Protein Rigid Body Docking by Incorporating Force Field for Molecular Dynamics Simulation into the Scoring Function.

    PubMed

    Iwakiri, Junichi; Hamada, Michiaki; Asai, Kiyoshi; Kameda, Tomoshi

    2016-09-13

    RNA-protein interactions play fundamental roles in many biological processes. To understand these interactions, it is necessary to know the three-dimensional structures of RNA-protein complexes. However, determining the tertiary structure of these complexes is often difficult, suggesting that an accurate rigid body docking for RNA-protein complexes is needed. In general, the rigid body docking process is divided into two steps: generating candidate structures from the individual RNA and protein structures and then narrowing down the candidates. In this study, we focus on the former problem to improve the prediction accuracy in RNA-protein docking. Our method is based on the integration of physicochemical information about RNA into ZDOCK, which is known as one of the most successful computer programs for protein-protein docking. Because recent studies showed the current force field for molecular dynamics simulation of protein and nucleic acids is quite accurate, we modeled the physicochemical information about RNA by force fields such as AMBER and CHARMM. A comprehensive benchmark of RNA-protein docking, using three recently developed data sets, reveals the remarkable prediction accuracy of the proposed method compared with existing programs for docking: the highest success rate is 34.7% for the predicted structure of the RNA-protein complex with the best score and 79.2% for 3,600 predicted ones. Three full atomistic force fields for RNA (AMBER94, AMBER99, and CHARMM22) produced almost the same accurate result, which showed current force fields for nucleic acids are quite accurate. In addition, we found that the electrostatic interaction and the representation of shape complementary between protein and RNA plays the important roles for accurate prediction of the native structures of RNA-protein complexes. PMID:27494732

  12. Multiple zone coal degasification potential in the Warrior coal field of Alabama

    SciTech Connect

    Graves, S.L.; Patton, A.F.; Beavers, W.M.

    1983-01-01

    The upper Pottsville Formation in the Warrior coal field of Alabama has 7 recognized groups of bituminous coal seams. Three of these groups, the Pratt, Mary Lee, and Black Creek, consist of seams containing commercially significant quantities of methane. Each group has several seams within a vertical interval that, in many areas, can be collectively stimulated. In parts of the Warrior coal field, where all 3 groups can be penetrated in one vertical borehole, the potential production from multiple zone completion wells can result in commercially profitable wells. Various open hole and through-the-casing completion procedures are being applied, resulting in successful methane production from these multiple-zone-coal-gas wells.

  13. Multiple zone coal degasification potential in Warrior coal field of Alabama

    SciTech Connect

    Graves, S.L.; Patton, A.F.; Beavers, W.M.

    1983-09-01

    The upper Pottsville Formation in the Warrior coal field of Alabama has seven recognized groups of bituminous coal seams. Three of these groups, the Pratt, Mary Lee, and Black Creek, consist of seams containing commercially significant quantities of methane. Each group has several seams within a vertical interval that, in many areas, can be stimulated collectively. In parts of the Warrior coal field, where all three groups can be penetrated in one vertical borehole, the potential production from multiple zone completion wells can result in commerically profitable wells. Various open-hole and through-the-casing completion procedures are being applied, resulting in successful methane production from these multiple zone coal gas wells.

  14. Real-Time Correction of Rigid-Body-Motion-Induced Phase Errors for Diffusion-Weighted Steady State Free Precession Imaging

    PubMed Central

    O’Halloran, R; Aksoy, M; Aboussouan, E; Peterson, E; Van, A; Bammer, R

    2014-01-01

    Purpose Diffusion contrast in diffusion-weighted steady state free precession MRI is generated through the constructive addition of signal from many coherence pathways. Motion-induced phase causes destructive interference which results in loss of signal magnitude and diffusion contrast. In this work, a 3D navigator-based real-time correction of the rigid-body-motion-induced phase errors is developed for diffusion-weighted steady state free precession MRI. Methods The efficacy of the real-time prospective correction method in preserving phase coherence of the steady-state is tested in 3D phantom experiments and 3D scans of healthy human subjects. Results In nearly all experiments, the signal magnitude in images obtained with proposed prospective correction was higher than the signal magnitude in images obtained with no correction. In the human subjects the mean magnitude signal in the data was up to 30 percent higher with prospective motion correction than without. Prospective correction never resulted in a decrease in mean signal magnitude in either the data or in the images. Conclusions The proposed prospective motion correction method is shown to preserve the phase coherence of the steady state in diffusion-weighted steady state free precession MRI, thus mitigating signal magnitude losses that would confound the desired diffusion contrast. PMID:24715414

  15. Use of Three-Dimensional Gaussian Interpolation in the Projector/Backprojector Pair of Iterative Reconstruction for Compensation of Known Rigid-Body Motion in SPECT

    PubMed Central

    Feng, Bing; Gifford, Howard C.; Beach, Richard D.; Boening, Guido; Gennert, Michael A.; King, Michael A.

    2008-01-01

    Due to the extended imaging times employed in SPECT and PET, patient motion during imaging is a common clinical occurrence. The fast and accurate correction of the three-dimensional (3D) translational and rotational patient motion in iterative reconstruction is thus necessary to address this important cause of artifacts. We propose a method of incorporating 3D Gaussian interpolation in the projector/backprojector pair to facilitate compensation for rigid-body motion in addition to attenuation and distance-dependent blurring. The method works as the interpolation step for moving the current emission voxel estimates and attenuation maps in the global coordinate system to the new patient location in the rotating coordinate system when calculating the expected projection. It also is employed for moving back the backprojection of the ratio of the measured projection to the expected projection and backprojection of the unit value (sensitivity factor) to the original location. MCAT simulations with known six-degree-of-freedom (6DOF) motion were employed to evaluate the accuracy of our method of motion compensation. We also tested the method with acquisitions of the Data Spectrum Anthropomorphic phantom where motion during SPECT acquisition was measured using the Polaris IR motion tracking system. No motion artifacts were seen on the reconstructions with the motion compensation. PMID:16827485

  16. A 3D, fully Eulerian, VOF-based solver to study the interaction between two fluids and moving rigid bodies using the fictitious domain method

    NASA Astrophysics Data System (ADS)

    Pathak, Ashish; Raessi, Mehdi

    2016-04-01

    We present a three-dimensional (3D) and fully Eulerian approach to capturing the interaction between two fluids and moving rigid structures by using the fictitious domain and volume-of-fluid (VOF) methods. The solid bodies can have arbitrarily complex geometry and can pierce the fluid-fluid interface, forming contact lines. The three-phase interfaces are resolved and reconstructed by using a VOF-based methodology. Then, a consistent scheme is employed for transporting mass and momentum, allowing for simulations of three-phase flows of large density ratios. The Eulerian approach significantly simplifies numerical resolution of the kinematics of rigid bodies of complex geometry and with six degrees of freedom. The fluid-structure interaction (FSI) is computed using the fictitious domain method. The methodology was developed in a message passing interface (MPI) parallel framework accelerated with graphics processing units (GPUs). The computationally intensive solution of the pressure Poisson equation is ported to GPUs, while the remaining calculations are performed on CPUs. The performance and accuracy of the methodology are assessed using an array of test cases, focusing individually on the flow solver and the FSI in surface-piercing configurations. Finally, an application of the proposed methodology in simulations of the ocean wave energy converters is presented.

  17. Improvement of registration accuracy in accelerated partial breast irradiation using the point-based rigid-body registration algorithm for patients with implanted fiducial markers

    SciTech Connect

    Inoue, Minoru; Yoshimura, Michio Sato, Sayaka; Nakamura, Mitsuhiro; Yamada, Masahiro; Hirata, Kimiko; Ogura, Masakazu; Hiraoka, Masahiro; Sasaki, Makoto; Fujimoto, Takahiro

    2015-04-15

    Purpose: To investigate image-registration errors when using fiducial markers with a manual method and the point-based rigid-body registration (PRBR) algorithm in accelerated partial breast irradiation (APBI) patients, with accompanying fiducial deviations. Methods: Twenty-two consecutive patients were enrolled in a prospective trial examining 10-fraction APBI. Titanium clips were implanted intraoperatively around the seroma in all patients. For image-registration, the positions of the clips in daily kV x-ray images were matched to those in the planning digitally reconstructed radiographs. Fiducial and gravity registration errors (FREs and GREs, respectively), representing resulting misalignments of the edge and center of the target, respectively, were compared between the manual and algorithm-based methods. Results: In total, 218 fractions were evaluated. Although the mean FRE/GRE values for the manual and algorithm-based methods were within 3 mm (2.3/1.7 and 1.3/0.4 mm, respectively), the percentages of fractions where FRE/GRE exceeded 3 mm using the manual and algorithm-based methods were 18.8%/7.3% and 0%/0%, respectively. Manual registration resulted in 18.6% of patients with fractions of FRE/GRE exceeding 5 mm. The patients with larger clip deviation had significantly more fractions showing large FRE/GRE using manual registration. Conclusions: For image-registration using fiducial markers in APBI, the manual registration results in more fractions with considerable registration error due to loss of fiducial objectivity resulting from their deviation. The authors recommend the PRBR algorithm as a safe and effective strategy for accurate, image-guided registration and PTV margin reduction.

  18. The equations of Lagrange for a continuous deformable body with rigid body degrees of freedom, written in a momentum based formulation

    NASA Astrophysics Data System (ADS)

    Irschik, H.; Krommer, M.; Nader, M.; Vetyukov, Y.; von Garssen, H.-G.

    2015-01-01

    The present paper is concerned with Lagrange's Equations, applied to a deformable body in the presence of rigid body degrees of freedom. The Lagrange description of Continuum Mechanics is used. An exact version of the Equations is derived first. This version, which represents an identical extension of the Fundamental Law of Dynamics, does involve the idea of virtual motions. The virtual motion is described in the framework of the Ritz-Ansatz, but our derivation does not make use of D'Alemberts principle, the principle of virtual work, or variational principles. From the exact version, by involving arguments related to the Galerkin approximation technique, we derive an approximate Ritz type version of Lagrange's Equations. This approximate version coincides with the traditional one, which is based on the notion of kinetic energy. However, since our derivation stems from the Fundamental Law of Dynamics, we have at our disposal an alternative formulation, which is based on the notion of local momentum. This momentum based version, which is the main topic of the present contribution, can be used for the purpose of performing independent checks of the energy based version of Lagrange's Equations. The momentum based version also clarifies that and how certain terms in the energy based version do cancel out. The momentum based version is worked out in the framework of the Floating Frame of Reference Formulation of Multibody Dynamics. Explicit formulas for the single terms of Lagrange's Equations are derived for the translational, rotational and flexible degrees of freedom of the deformable body, respectively. Corresponding Lagrange's Equations are explained in the light of the relations of Balance of Total Momentum, Balance of Total Moment of Momentum, of the Mean Stress Theorem and the notion of Virial of Forces. An embedding into the literature is given.

  19. A review of a method for dynamic load distribution, dynamic modeling, and explicit internal force control when two serial link manipulators mutually lift and transport a rigid body object

    SciTech Connect

    Unseren, M.A.

    1997-09-01

    The report reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restricts the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system.

  20. Research on the automatic laser navigation system of the tunnel boring machine

    NASA Astrophysics Data System (ADS)

    Liu, Yake; Li, Yueqiang

    2011-12-01

    By establishing relevant coordinates of the Automatic Laser Navigation System, the basic principle of the system which accesses the TBM three-dimensional reference point and yawing angle by mathematical transformation between TBM, target prism and earth coordinate systems is discussed deeply in details. According to the way of rigid body descriptions of its posture, TBM attitude parameters measurement and data acquisition methods are proposed, and measures to improve the accuracy of the Laser Navigation System are summarized.

  1. Combined Use of Residual Dipolar Couplings and Solution X-ray Scattering To Rapidly Probe Rigid-Body Conformational Transitions in a Non-phosphorylatable Active-Site Mutant of the 128 kDa Enzyme I Dimer

    SciTech Connect

    Takayama, Yuki; Schwieters, Charles D.; Grishaev, Alexander; Ghirlando, Rodolfo; Clore, G. Marius

    2012-10-23

    The first component of the bacterial phosphotransferase system, enzyme I (EI), is a multidomain 128 kDa dimer that undergoes large rigid-body conformational transitions during the course of its catalytic cycle. Here we investigate the solution structure of a non-phosphorylatable active-site mutant in which the active-site histidine is substituted by glutamine. We show that perturbations in the relative orientations and positions of the domains and subdomains can be rapidly and reliably determined by conjoined rigid-body/torsion angle/Cartesian simulated annealing calculations driven by orientational restraints from residual dipolar couplings and shape and translation information afforded by small- and wide-angle X-ray scattering. Although histidine and glutamine are isosteric, the conformational space available to a Gln side chain is larger than that for the imidazole ring of His. An additional hydrogen bond between the side chain of Gln189 located on the EIN{sup {alpha}/{beta}} subdomain and an aspartate (Asp129) on the EIN{sup {alpha}} subdomain results in a small ({approx}9{sup o}) reorientation of the EIN{sup {alpha}} and EIN{sup {alpha}/{beta}} subdomains that is in turn propagated to a larger reorientation ({approx}26{sup o}) of the EIN domain relative to the EIC dimerization domain, illustrating the positional sensitivity of the EIN domain and its constituent subdomains to small structural perturbations.

  2. Reversal of left ventricular “rigid body rotation” during dipyridamole-induced stress in a patient with stable angina: a case from the three-dimensional speckle tracking echocardiographic MAGYAR-Stress Study

    PubMed Central

    Szántó, Gyula; Kalapos, Anita; Domsik, Péter; Forster, Tamás

    2016-01-01

    The left ventricular (LV) twist is defined as the wringing motion of the heart around its long-axis in systole caused by oppositely directed counterclockwise apical and clockwise basal rotations resulted from the movement of two orthogonally oriented muscular bands. In some clinical circumstances, rotation at both basal and apical levels of the LV occurred in the same clockwise or counterclockwise direction during systole resulting the near absence of LV twist as called left ventricular “rigid body rotation” (LV-RBR). Hereby we present that LV-RBR normalization of LV rotational mechanics could be demonstrated at maximum hyperaemia during dipyridamole-induced stress by three-dimensional (3D) speckle tracking echocardiography in a patient with stable angina. PMID:27429914

  3. Optimization of an installation angle of a root-cutting blade for an automatic spinach harvester

    NASA Astrophysics Data System (ADS)

    Fujisawa, A.; Chida, Y.

    2016-09-01

    This paper presents an optimization of the installation angle of a root-cutting blade relative to the arm of an automatic spinach harvester. In the harvesting operation, the blade, which is a rigid body, moves under the planted rows in soil of powder consistency to cut the roots of the spinach and to harvest the spinach on a conveyor. Therefore, the interaction between a rigid body and powder is an important consideration. Experiments were conducted on the design of the harvester. The experiments revealed that a certain path of the blade is more favorable for both harvesting spinach easily and minimizing the amount of soil removed by the blade. In this paper, without revising the favorable path, the optimum installation angle of the blade is derived. To derive the installation angle, a nonlinear optimization problem is solved as an evaluation function consisting of the volume of soil pushed by the blade and the installation angle, which is a design parameter. The utility of the installation angle is confirmed by the Discrete Element Method (DEM), which analyzes the interaction between a rigid body and powder.

  4. Rigid Body Rate Inference from Attitude Variation

    NASA Technical Reports Server (NTRS)

    Bar-Itzhack, I. Y.; Harman, Richard R.; Thienel, Julie K.

    2006-01-01

    In this paper we research the extraction of the angular rate vector from attitude information without differentiation, in particular from quaternion measurements. We show that instead of using a Kalman filter of some kind, it is possible to obtain good rate estimates, suitable for spacecraft attitude control loop damping, using simple feedback loops, thereby eliminating the need for recurrent covariance computation performed when a Kalman filter is used. This considerably simplifies the computations required for rate estimation in gyro-less spacecraft. Some interesting qualities of the Kalman filter gain are explored, proven and utilized. We examine two kinds of feedback loops, one with varying gain that is proportional to the well known Q matrix, which is computed using the measured quaternion, and the other type of feedback loop is one with constant coefficients. The latter type includes two kinds; namely, a proportional feedback loop, and a proportional-integral feedback loop. The various schemes are examined through simulations and their performance is compared. It is shown that all schemes are adequate for extracting the angular velocity at an accuracy suitable for control loop damping.

  5. Automatic Imitation

    ERIC Educational Resources Information Center

    Heyes, Cecilia

    2011-01-01

    "Automatic imitation" is a type of stimulus-response compatibility effect in which the topographical features of task-irrelevant action stimuli facilitate similar, and interfere with dissimilar, responses. This article reviews behavioral, neurophysiological, and neuroimaging research on automatic imitation, asking in what sense it is "automatic"…

  6. Flow Rates Measurement and Uncertainty Analysis in Multiple-Zone Water-Injection Wells from Fluid Temperature Profiles.

    PubMed

    Reges, José E O; Salazar, A O; Maitelli, Carla W S P; Carvalho, Lucas G; Britto, Ursula J B

    2016-07-13

    This work is a contribution to the development of flow sensors in the oil and gas industry. It presents a methodology to measure the flow rates into multiple-zone water-injection wells from fluid temperature profiles and estimate the measurement uncertainty. First, a method to iteratively calculate the zonal flow rates using the Ramey (exponential) model was described. Next, this model was linearized to perform an uncertainty analysis. Then, a computer program to calculate the injected flow rates from experimental temperature profiles was developed. In the experimental part, a fluid temperature profile from a dual-zone water-injection well located in the Northeast Brazilian region was collected. Thus, calculated and measured flow rates were compared. The results proved that linearization error is negligible for practical purposes and the relative uncertainty increases as the flow rate decreases. The calculated values from both the Ramey and linear models were very close to the measured flow rates, presenting a difference of only 4.58 m³/d and 2.38 m³/d, respectively. Finally, the measurement uncertainties from the Ramey and linear models were equal to 1.22% and 1.40% (for injection zone 1); 10.47% and 9.88% (for injection zone 2). Therefore, the methodology was successfully validated and all objectives of this work were achieved.

  7. Flow Rates Measurement and Uncertainty Analysis in Multiple-Zone Water-Injection Wells from Fluid Temperature Profiles.

    PubMed

    Reges, José E O; Salazar, A O; Maitelli, Carla W S P; Carvalho, Lucas G; Britto, Ursula J B

    2016-01-01

    This work is a contribution to the development of flow sensors in the oil and gas industry. It presents a methodology to measure the flow rates into multiple-zone water-injection wells from fluid temperature profiles and estimate the measurement uncertainty. First, a method to iteratively calculate the zonal flow rates using the Ramey (exponential) model was described. Next, this model was linearized to perform an uncertainty analysis. Then, a computer program to calculate the injected flow rates from experimental temperature profiles was developed. In the experimental part, a fluid temperature profile from a dual-zone water-injection well located in the Northeast Brazilian region was collected. Thus, calculated and measured flow rates were compared. The results proved that linearization error is negligible for practical purposes and the relative uncertainty increases as the flow rate decreases. The calculated values from both the Ramey and linear models were very close to the measured flow rates, presenting a difference of only 4.58 m³/d and 2.38 m³/d, respectively. Finally, the measurement uncertainties from the Ramey and linear models were equal to 1.22% and 1.40% (for injection zone 1); 10.47% and 9.88% (for injection zone 2). Therefore, the methodology was successfully validated and all objectives of this work were achieved. PMID:27420068

  8. Flow Rates Measurement and Uncertainty Analysis in Multiple-Zone Water-Injection Wells from Fluid Temperature Profiles

    PubMed Central

    Reges, José E. O.; Salazar, A. O.; Maitelli, Carla W. S. P.; Carvalho, Lucas G.; Britto, Ursula J. B.

    2016-01-01

    This work is a contribution to the development of flow sensors in the oil and gas industry. It presents a methodology to measure the flow rates into multiple-zone water-injection wells from fluid temperature profiles and estimate the measurement uncertainty. First, a method to iteratively calculate the zonal flow rates using the Ramey (exponential) model was described. Next, this model was linearized to perform an uncertainty analysis. Then, a computer program to calculate the injected flow rates from experimental temperature profiles was developed. In the experimental part, a fluid temperature profile from a dual-zone water-injection well located in the Northeast Brazilian region was collected. Thus, calculated and measured flow rates were compared. The results proved that linearization error is negligible for practical purposes and the relative uncertainty increases as the flow rate decreases. The calculated values from both the Ramey and linear models were very close to the measured flow rates, presenting a difference of only 4.58 m³/d and 2.38 m³/d, respectively. Finally, the measurement uncertainties from the Ramey and linear models were equal to 1.22% and 1.40% (for injection zone 1); 10.47% and 9.88% (for injection zone 2). Therefore, the methodology was successfully validated and all objectives of this work were achieved. PMID:27420068

  9. Automatic 3D image registration using voxel similarity measurements based on a genetic algorithm

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Sullivan, John M., Jr.; Kulkarni, Praveen; Murugavel, Murali

    2006-03-01

    An automatic 3D non-rigid body registration system based upon the genetic algorithm (GA) process is presented. The system has been successfully applied to 2D and 3D situations using both rigid-body and affine transformations. Conventional optimization techniques and gradient search strategies generally require a good initial start location. The GA approach avoids the local minima/maxima traps of conventional optimization techniques. Based on the principles of Darwinian natural selection (survival of the fittest), the genetic algorithm has two basic steps: 1. Randomly generate an initial population. 2. Repeated application of the natural selection operation until a termination measure is satisfied. The natural selection process selects individuals based on their fitness to participate in the genetic operations; and it creates new individuals by inheritance from both parents, genetic recombination (crossover) and mutation. Once the termination criteria are satisfied, the optimum is selected from the population. The algorithm was applied on 2D and 3D magnetic resonance images (MRI). It does not require any preprocessing such as threshold, smoothing, segmentation, or definition of base points or edges. To evaluate the performance of the GA registration, the results were compared with results of the Automatic Image Registration technique (AIR) and manual registration which was used as the gold standard. Results showed that our GA implementation was a robust algorithm and gives very close results to the gold standard. A pre-cropping strategy was also discussed as an efficient preprocessing step to enhance the registration accuracy.

  10. Automatic Stabilization

    NASA Technical Reports Server (NTRS)

    Haus, FR

    1936-01-01

    This report lays more stress on the principles underlying automatic piloting than on the means of applications. Mechanical details of servomotors and the mechanical release device necessary to assure instantaneous return of the controls to the pilot in case of malfunction are not included. Descriptions are provided of various commercial systems.

  11. Automatic registration of serial mammary gland sections

    SciTech Connect

    Arganda-Carreras, Ignacio; Fernandez-Gonzalez, Rodrigo; Ortiz-de-Solorzano, Carlos

    2004-04-13

    We present two new methods for automatic registration of microscope images of consecutive tissue sections. They represent two possibilities for the first step in the 3-D reconstruction of histological structures from serially sectioned tissue blocks. The goal is to accurately align the sections in order to place every relevant shape contained in each image in front of its corresponding shape in the following section before detecting the structures of interest and rendering them in 3D. This is accomplished by finding the best rigid body transformation (translation and rotation) of the image being registered by maximizing a matching function based on the image content correlation. The first method makes use of the entire image information, whereas the second one uses only the information located at specific sites, as determined by the segmentation of the most relevant tissue structures. To reduce computing time, we use a multiresolution pyramidal approach that reaches the best registration transformation in increasing resolution steps. In each step, a subsampled version of the images is used. Both methods rely on a binary image which is a thresholded version of the Sobel gradients of the image (first method) or a set of boundaries manually or automatically obtained that define important histological structures of the sections. Then distance-transform of the binary image is computed. A proximity function is then calculated between the distance image of the image being registered and that of the reference image. The transformation providing a maximum of the proximity function is then used as the starting point of the following step. This is iterated until the registration error lies below a minimum value.

  12. AUTOMATIC COUNTER

    DOEpatents

    Robinson, H.P.

    1960-06-01

    An automatic counter of alpha particle tracks recorded by a sensitive emulsion of a photographic plate is described. The counter includes a source of mcdulated dark-field illumination for developing light flashes from the recorded particle tracks as the photographic plate is automatically scanned in narrow strips. Photoelectric means convert the light flashes to proportional current pulses for application to an electronic counting circuit. Photoelectric means are further provided for developing a phase reference signal from the photographic plate in such a manner that signals arising from particle tracks not parallel to the edge of the plate are out of phase with the reference signal. The counting circuit includes provision for rejecting the out-of-phase signals resulting from unoriented tracks as well as signals resulting from spurious marks on the plate such as scratches, dust or grain clumpings, etc. The output of the circuit is hence indicative only of the tracks that would be counted by a human operator.

  13. Automatic transmission

    SciTech Connect

    Ohkubo, M.

    1988-02-16

    An automatic transmission is described combining a stator reversing type torque converter and speed changer having first and second sun gears comprising: (a) a planetary gear train composed of first and second planetary gears sharing one planetary carrier in common; (b) a clutch and requisite brakes to control the planetary gear train; and (c) a speed-increasing or speed-decreasing mechanism is installed both in between a turbine shaft coupled to a turbine of the stator reversing type torque converter and the first sun gear of the speed changer, and in between a stator shaft coupled to a reversing stator and the second sun gear of the speed changer.

  14. Automatic stabilization

    NASA Technical Reports Server (NTRS)

    Haus, FR

    1936-01-01

    This report concerns the study of automatic stabilizers and extends it to include the control of the three-control system of the airplane instead of just altitude control. Some of the topics discussed include lateral disturbed motion, static stability, the mathematical theory of lateral motion, and large angles of incidence. Various mechanisms and stabilizers are also discussed. The feeding of Diesel engines by injection pumps actuated by engine compression, achieves the required high speeds of injection readily and permits rigorous control of the combustible charge introduced into each cylinder and of the peak pressure in the resultant cycle.

  15. Automatic transmission

    SciTech Connect

    Miki, N.

    1988-10-11

    This patent describes an automatic transmission including a fluid torque converter, a first gear unit having three forward-speed gears and a single reverse gear, a second gear unit having a low-speed gear and a high-speed gear, and a hydraulic control system, the hydraulic control system comprising: a source of pressurized fluid; a first shift valve for controlling the shifting between the first-speed gear and the second-speed gear of the first gear unit; a second shift valve for controlling the shifting between the second-speed gear and the third-speed gear of the first gear unit; a third shift valve equipped with a spool having two positions for controlling the shifting between the low-speed gear and the high-speed gear of the second gear unit; a manual selector valve having a plurality of shift positions for distributing the pressurized fluid supply from the source of pressurized fluid to the first, second and third shift valves respectively; first, second and third solenoid valves corresponding to the first, second and third shift valves, respectively for independently controlling the operation of the respective shift valves, thereby establishing a six forward-speed automatic transmission by combining the low-speed gear and the high-speed gear of the second gear unit with each of the first-speed gear, the second speed gear and the third-speed gear of the first gear unit; and means to fixedly position the spool of the third shift valve at one of the two positions by supplying the pressurized fluid to the third shift valve when the manual selector valve is shifted to a particular shift position, thereby locking the second gear unit in one of low-speed gear and the high-speed gear, whereby the six forward-speed automatic transmission is converted to a three forward-speed automatic transmission when the manual selector valve is shifted to the particular shift position.

  16. Automatic transmission

    SciTech Connect

    Aoki, H.

    1989-03-21

    An automatic transmission is described, comprising: a torque converter including an impeller having a connected member, a turbine having an input member and a reactor; and an automatic transmission mechanism having first to third clutches and plural gear units including a single planetary gear unit with a ring gear and a dual planetary gear unit with a ring gear. The single and dual planetary gear units have respective carriers integrally coupled with each other and respective sun gears integrally coupled with each other, the input member of the turbine being coupled with the ring gear of the single planetary gear unit through the first clutch, and being coupled with the sun gear through the second clutch. The connected member of the impeller is coupled with the ring gear of the dual planetary gear of the dual planetary gear unit is made to be and ring gear of the dual planetary gear unit is made to be restrained as required, and the carrier is coupled with an output member.

  17. Automatic transmission

    SciTech Connect

    Miura, M.; Inuzuka, T.

    1986-08-26

    1. An automatic transmission with four forward speeds and one reverse position, is described which consists of: an input shaft; an output member; first and second planetary gear sets each having a sun gear, a ring gear and a carrier supporting a pinion in mesh with the sun gear and ring gear; the carrier of the first gear set, the ring gear of the second gear set and the output member all being connected; the ring gear of the first gear set connected to the carrier of the second gear set; a first clutch means for selectively connecting the input shaft to the sun gear of the first gear set, including friction elements, a piston selectively engaging the friction elements and a fluid servo in which hydraulic fluid is selectively supplied to the piston; a second clutch means for selectively connecting the input shaft to the sun gear of the second gear set a third clutch means for selectively connecting the input shaft to the carrier of the second gear set including friction elements, a piston selectively engaging the friction elements and a fluid servo in which hydraulic fluid is selectively supplied to the piston; a first drive-establishing means for selectively preventing rotation of the ring gear of the first gear set and the carrier of the second gear set in only one direction and, alternatively, in any direction; a second drive-establishing means for selectively preventing rotation of the sun gear of the second gear set; and a drum being open to the first planetary gear set, with a cylindrical intermediate wall, an inner peripheral wall and outer peripheral wall and forming the hydraulic servos of the first and third clutch means between the intermediate wall and the inner peripheral wall and between the intermediate wall and the outer peripheral wall respectively.

  18. 3-D rigid body tracking using vision and depth sensors.

    PubMed

    Gedik, O Serdar; Alatan, A Aydn

    2013-10-01

    In robotics and augmented reality applications, model-based 3-D tracking of rigid objects is generally required. With the help of accurate pose estimates, it is required to increase reliability and decrease jitter in total. Among many solutions of pose estimation in the literature, pure vision-based 3-D trackers require either manual initializations or offline training stages. On the other hand, trackers relying on pure depth sensors are not suitable for AR applications. An automated 3-D tracking algorithm, which is based on fusion of vision and depth sensors via extended Kalman filter, is proposed in this paper. A novel measurement-tracking scheme, which is based on estimation of optical flow using intensity and shape index map data of 3-D point cloud, increases 2-D, as well as 3-D, tracking performance significantly. The proposed method requires neither manual initialization of pose nor offline training, while enabling highly accurate 3-D tracking. The accuracy of the proposed method is tested against a number of conventional techniques, and a superior performance is clearly observed in terms of both objectively via error metrics and subjectively for the rendered scenes. PMID:23955795

  19. Fluid-Structure Interactions with Flexible and Rigid Bodies

    NASA Astrophysics Data System (ADS)

    Daily, David Jesse

    Fluid structure interactions occur to some extent in nearly every type of fluid flow. Understanding how structures interact with fluids and visa-versa is of vital importance in many engineering applications. The purpose of this research is to explore how fluids interact with flexible and rigid structures. A computational model was used to model the fluid structure interactions of vibrating synthetic vocal folds. The model simulated the coupling of the fluid and solid domains using a fluid-structure interface boundary condition. The fluid domain used a slightly compressible flow solver to allow for the possibility of acoustic coupling with the subglottal geometry and vibration of the vocal fold model. As the subglottis lengthened, the frequency of vibration decreased until a new acoustic mode could form in the subglottis. Synthetic aperture particle image velocimetry (SAPIV) is a three-dimensional particle tracking technique. SAPIV was used to image the jet of air that emerges from vibrating human vocal folds (glottal jet) during phonation. The three-dimensional reconstruction of the glottal jet found faint evidence of flow characteristics seen in previous research, such as axis-switching, but did not have sufficient resolution to detect small features. SAPIV was further applied to reconstruct the smaller flow characteristics of the glottal jet of vibrating synthetic vocal folds. Two- and four-layer synthetic vocal fold models were used to determine how the glottal jet from the synthetic models compared to the glottal jet from excised human vocal folds. The two- and four-layer models clearly exhibited axis-switching which has been seen in other 3D analyses of the glottal jet. Cavitation in a quiescent fluid can break a rigid structure such as a glass bottle. A new cavitation number was derived to include acceleration and pressure head at cavitation onset. A cavitation stick was used to validate the cavitation number by filling it with different depths and hitting the stick to cause fluid cavitation. Acceleration was measured using an accelerometer and cavitation bubbles were detected using a high-speed camera. Cavitation in an accelerating fluid occurred at a cavitation number of 1. Keywords: Fluid structure interaction, vocal folds, acoustics, SAPIV, cavitation, slightly compressible

  20. Robust tracking control of a magnetically suspended rigid body

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Cox, David E.

    1994-01-01

    This study is an application of H-infinity and micro-synthesis for designing robust tracking controllers for the Large Angle Magnetic Suspension Test Facility. The modeling, design, analysis, simulation, and testing of a control law that guarantees tracking performance under external disturbances and model uncertainties is investigated. The type of uncertainties considered and the tracking performance metric used is discussed. This study demonstrates the tradeoff between tracking performance at low frequencies and robustness at high frequencies. Two sets of controllers were designed and tested. The first set emphasized performance over robustness, while the second set traded off performance for robustness. Comparisons of simulation and test results are also included. Current simulation and experimental results indicate that reasonably good robust tracking performance can be attained for this system using multivariable robust control approach.

  1. 3-D rigid body tracking using vision and depth sensors.

    PubMed

    Gedik, O Serdar; Alatan, A Aydn

    2013-10-01

    In robotics and augmented reality applications, model-based 3-D tracking of rigid objects is generally required. With the help of accurate pose estimates, it is required to increase reliability and decrease jitter in total. Among many solutions of pose estimation in the literature, pure vision-based 3-D trackers require either manual initializations or offline training stages. On the other hand, trackers relying on pure depth sensors are not suitable for AR applications. An automated 3-D tracking algorithm, which is based on fusion of vision and depth sensors via extended Kalman filter, is proposed in this paper. A novel measurement-tracking scheme, which is based on estimation of optical flow using intensity and shape index map data of 3-D point cloud, increases 2-D, as well as 3-D, tracking performance significantly. The proposed method requires neither manual initialization of pose nor offline training, while enabling highly accurate 3-D tracking. The accuracy of the proposed method is tested against a number of conventional techniques, and a superior performance is clearly observed in terms of both objectively via error metrics and subjectively for the rendered scenes.

  2. Robust tracking control of a magnetically suspended rigid body

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Cox, David E.

    1993-01-01

    This study is an application of H-infinity and microsynthesis for designing robust tracking controllers for the Large Angle Magnetic Suspension Test Facility. The modeling, design, analysis, simulation, and testing of a control law that guarantees tracking performance under external disturbances and model uncertainties is investigated. The type of uncertainties considered and the tracking performance metric used is discussed. This study demonstrates the tradeoff between tracking performance at low frequencies and robustness at high frequencies. Two sets of controllers were designed and tested. The first set emphasized performance over robustness, while the second set traded off performance for robustness. Comparisons of simulation and test results are also included. Current simulation and experimental results indicate that reasonably good robust tracking performance can be attained for this system, using multivariable robust control approach.

  3. Hamiltonian Dynamics of Spider-Type Multirotor Rigid Bodies Systems

    SciTech Connect

    Doroshin, Anton V.

    2010-03-01

    This paper sets out to develop a spider-type multiple-rotor system which can be used for attitude control of spacecraft. The multirotor system contains a large number of rotor-equipped rays, so it was called a 'Spider-type System', also it can be called 'Rotary Hedgehog'. These systems allow using spinups and captures of conjugate rotors to perform compound attitude motion of spacecraft. The paper describes a new method of spacecraft attitude reorientation and new mathematical model of motion in Hamilton form. Hamiltonian dynamics of the system is investigated with the help of Andoyer-Deprit canonical variables. These variables allow obtaining exact solution for hetero- and homoclinic orbits in phase space of the system motion, which are very important for qualitative analysis.

  4. Rigid-body molecular dynamics of DNA inside a nucleosome.

    PubMed

    Fathizadeh, Arman; Berdy Besya, Azim; Reza Ejtehadi, Mohammad; Schiessel, Helmut

    2013-03-01

    The majority of eukaryotic DNA, about three quarter, is wrapped around histone proteins forming so-called nucleosomes. To study nucleosomal DNA we introduce a coarse-grained molecular dynamics model based on sequence-dependent harmonic rigid base pair step parameters of DNA and nucleosomal binding sites. Mixed parametrization based on all-atom molecular dynamics and crystallographic data of protein-DNA structures is used for the base pair step parameters. The binding site parameters are adjusted by experimental B-factor values of the nucleosome crystal structure. The model is then used to determine the energy cost for placing a twist defect into the nucleosomal DNA which allows us to use Kramers theory to calculate nucleosome sliding caused by such defects. It is shown that the twist defect scenario together with the sequence-dependent elasticity of DNA can explain the slow time scales observed for nucleosome mobility along DNA. With this method we also show how the twist defect mechanism leads to a higher mobility of DNA in the presence of sin mutations near the dyad axis. Finally, by performing simulations on 5s rDNA, 601, and telomeric base pair sequences, it is demonstrated that the current model is a powerful tool to predict nucleosome positioning. PMID:23475204

  5. [Wearable Automatic External Defibrillators].

    PubMed

    Luo, Huajie; Luo, Zhangyuan; Jin, Xun; Zhang, Leilei; Wang, Changjin; Zhang, Wenzan; Tu, Quan

    2015-11-01

    Defibrillation is the most effective method of treating ventricular fibrillation(VF), this paper introduces wearable automatic external defibrillators based on embedded system which includes EGG measurements, bioelectrical impedance measurement, discharge defibrillation module, which can automatic identify VF signal, biphasic exponential waveform defibrillation discharge. After verified by animal tests, the device can realize EGG acquisition and automatic identification. After identifying the ventricular fibrillation signal, it can automatic defibrillate to abort ventricular fibrillation and to realize the cardiac electrical cardioversion.

  6. Robust automatic rigid registration of MRI and X-ray using external fiducial markers for XFM-guided interventional procedures

    SciTech Connect

    George, Ashvin K.; Sonmez, Merdim; Lederman, Robert J.; Faranesh, Anthony Z.

    2011-01-15

    Purpose: In X-ray fused with MRI, previously gathered roadmap MRI volume images are overlaid on live X-ray fluoroscopy images to help guide the clinician during an interventional procedure. The incorporation of MRI data allows for the visualization of soft tissue that is poorly visualized under X-ray. The widespread clinical use of this technique will require fully automating as many components as possible. While previous use of this method has required time-consuming manual intervention to register the two modalities, in this article, the authors present a fully automatic rigid-body registration method. Methods: External fiducial markers that are visible under these two complimentary imaging modalities were used to register the X-ray images with the roadmap MR images. The method has three components: (a) The identification of the 3D locations of the markers from a full 3D MR volume, (b) the identification of the 3D locations of the markers from a small number of 2D X-ray fluoroscopy images, and (c) finding the rigid-body transformation that registers the two point sets in the two modalities. For part (a), the localization of the markers from MR data, the MR volume image was thresholded, connected voxels were segmented and labeled, and the centroids of the connected components were computed. For part (b), the X-ray projection images, produced by an image intensifier, were first corrected for distortions. Binary mask images of the markers were created from the distortion-corrected X-ray projection images by applying edge detection, pattern recognition, and image morphological operations. The markers were localized in the X-ray frame using an iterative backprojection-based method which segments voxels in the volume of interest, discards false positives based on the previously computed edge-detected projections, and calculates the locations of the true markers as the centroids of the clusters of voxels that remain. For part (c), a variant of the iterative closest

  7. Robust automatic rigid registration of MRI and X-ray using external fiducial markers for XFM-guided interventional procedures

    PubMed Central

    George, Ashvin K.; Sonmez, Merdim; Lederman, Robert J.; Faranesh, Anthony Z.

    2011-01-01

    Purpose: In X-ray fused with MRI, previously gathered roadmap MRI volume images are overlaid on live X-ray fluoroscopy images to help guide the clinician during an interventional procedure. The incorporation of MRI data allows for the visualization of soft tissue that is poorly visualized under X-ray. The widespread clinical use of this technique will require fully automating as many components as possible. While previous use of this method has required time-consuming manual intervention to register the two modalities, in this article, the authors present a fully automatic rigid-body registration method. Methods: External fiducial markers that are visible under these two complimentary imaging modalities were used to register the X-ray images with the roadmap MR images. The method has three components: (a) The identification of the 3D locations of the markers from a full 3D MR volume, (b) the identification of the 3D locations of the markers from a small number of 2D X-ray fluoroscopy images, and (c) finding the rigid-body transformation that registers the two point sets in the two modalities. For part (a), the localization of the markers from MR data, the MR volume image was thresholded, connected voxels were segmented and labeled, and the centroids of the connected components were computed. For part (b), the X-ray projection images, produced by an image intensifier, were first corrected for distortions. Binary mask images of the markers were created from the distortion-corrected X-ray projection images by applying edge detection, pattern recognition, and image morphological operations. The markers were localized in the X-ray frame using an iterative backprojection-based method which segments voxels in the volume of interest, discards false positives based on the previously computed edge-detected projections, and calculates the locations of the true markers as the centroids of the clusters of voxels that remain. For part (c), a variant of the iterative closest

  8. Automatism and hypoglycaemia.

    PubMed

    Beaumont, Guy

    2007-02-01

    A case of a detained person (DP) suffering from insulin-dependent diabetes, who subsequently used the disorder in his defence as a reason to claim automatism, is discussed. The legal and medical history of automatism is outlined along with the present day situation. Forensic physicians should be aware when examining any diabetic that automatism may subsequently be claimed. With this in mind, the importance of relevant history taking specifically relating to diabetic control and symptoms is discussed.

  9. An anatomy of automatism.

    PubMed

    Mackay, R D

    2015-07-01

    The automatism defence has been described as a quagmire of law and as presenting an intractable problem. Why is this so? This paper will analyse and explore the current legal position on automatism. In so doing, it will identify the problems which the case law has created, including the distinction between sane and insane automatism and the status of the 'external factor doctrine', and comment briefly on recent reform proposals.

  10. An anatomy of automatism.

    PubMed

    Mackay, R D

    2015-07-01

    The automatism defence has been described as a quagmire of law and as presenting an intractable problem. Why is this so? This paper will analyse and explore the current legal position on automatism. In so doing, it will identify the problems which the case law has created, including the distinction between sane and insane automatism and the status of the 'external factor doctrine', and comment briefly on recent reform proposals. PMID:26378105

  11. Automatic crack propagation tracking

    NASA Technical Reports Server (NTRS)

    Shephard, M. S.; Weidner, T. J.; Yehia, N. A. B.; Burd, G. S.

    1985-01-01

    A finite element based approach to fully automatic crack propagation tracking is presented. The procedure presented combines fully automatic mesh generation with linear fracture mechanics techniques in a geometrically based finite element code capable of automatically tracking cracks in two-dimensional domains. The automatic mesh generator employs the modified-quadtree technique. Crack propagation increment and direction are predicted using a modified maximum dilatational strain energy density criterion employing the numerical results obtained by meshes of quadratic displacement and singular crack tip finite elements. Example problems are included to demonstrate the procedure.

  12. Automatic differentiation bibliography

    SciTech Connect

    Corliss, G.F.

    1992-07-01

    This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.

  13. Automatic Differentiation Package

    SciTech Connect

    Gay, David M.; Phipps, Eric; Bratlett, Roscoe

    2007-03-01

    Sacado is an automatic differentiation package for C++ codes using operator overloading and C++ templating. Sacado provide forward, reverse, and Taylor polynomial automatic differentiation classes and utilities for incorporating these classes into C++ codes. Users can compute derivatives of computations arising in engineering and scientific applications, including nonlinear equation solving, time integration, sensitivity analysis, stability analysis, optimization and uncertainity quantification.

  14. Automatic Versus Manual Indexing

    ERIC Educational Resources Information Center

    Vander Meulen, W. A.; Janssen, P. J. F. C.

    1977-01-01

    A comparative evaluation of results in terms of recall and precision from queries submitted to systems with automatic and manual subject indexing. Differences were attributed to query formulation. The effectiveness of automatic indexing was found equivalent to manual indexing. (Author/KP)

  15. Automatic and Flexible

    PubMed Central

    Hassin, Ran R.; Bargh, John A.; Zimerman, Shira

    2008-01-01

    Arguing from the nature of goal pursuit and from the economy of mental resources this paper suggests that automatic goal pursuit, much like its controlled counterpart, may be flexible. Two studies that employ goal priming procedures examine this hypothesis using the Wisconsin Card Sorting Test (Study 1) and a variation of the Iowa Gambling Task (Study 2). Implications of the results for our understanding of the dichotomy between automatic and controlled processes in general, and for our conception of automatic goal pursuit in particular, are discussed. PMID:19325712

  16. Automatic amino acid analyzer

    NASA Technical Reports Server (NTRS)

    Berdahl, B. J.; Carle, G. C.; Oyama, V. I.

    1971-01-01

    Analyzer operates unattended or up to 15 hours. It has an automatic sample injection system and can be programmed. All fluid-flow valve switching is accomplished pneumatically from miniature three-way solenoid pilot valves.

  17. AUTOMATIC MASS SPECTROMETER

    DOEpatents

    Hanson, M.L.; Tabor, C.D. Jr.

    1961-12-01

    A mass spectrometer for analyzing the components of a gas is designed which is capable of continuous automatic operation such as analysis of samples of process gas from a continuous production system where the gas content may be changing. (AEC)

  18. Automatic Payroll Deposit System.

    ERIC Educational Resources Information Center

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  19. Automatic switching matrix

    DOEpatents

    Schlecht, Martin F.; Kassakian, John G.; Caloggero, Anthony J.; Rhodes, Bruce; Otten, David; Rasmussen, Neil

    1982-01-01

    An automatic switching matrix that includes an apertured matrix board containing a matrix of wires that can be interconnected at each aperture. Each aperture has associated therewith a conductive pin which, when fully inserted into the associated aperture, effects electrical connection between the wires within that particular aperture. Means is provided for automatically inserting the pins in a determined pattern and for removing all the pins to permit other interconnecting patterns.

  20. A review of metaphase chromosome image selection techniques for automatic karyotype generation.

    PubMed

    Arora, Tanvi; Dhir, Renu

    2016-08-01

    The karyotype is analyzed to detect the genetic abnormalities. It is generated by arranging the chromosomes after extracting them from the metaphase chromosome images. The chromosomes are non-rigid bodies that contain the genetic information of an individual. The metaphase chromosome image spread contains the chromosomes, but these chromosomes are not distinct bodies; they can either be individual chromosomes or be touching one another; they may be bent or even may be overlapping and thus forming a cluster of chromosomes. The extraction of chromosomes from these touching and overlapping chromosomes is a very tedious process. The segmentation of a random metaphase chromosome image may not give us correct and accurate results. Therefore, before taking up a metaphase chromosome image for analysis, it must be analyzed for the orientation of the chromosomes it contains. The various reported methods for metaphase chromosome image selection for automatic karyotype generation are compared in this paper. After analysis, it has been concluded that each metaphase chromosome image selection method has its advantages and disadvantages.

  1. A new automatic synchronizer

    SciTech Connect

    Malm, C.F.

    1995-12-31

    A phase lock loop automatic synchronizer, PLLS, matches generator speed starting from dead stop to bus frequency, and then locks the phase difference at zero, thereby maintaining zero slip frequency while the generator breaker is being closed to the bus. The significant difference between the PLLS and a conventional automatic synchronizer is that there is no slip frequency difference between generator and bus. The PLL synchronizer is most advantageous when the penstock pressure fluctuates the grid frequency fluctuates, or both. The PLL synchronizer is relatively inexpensive. Hydroplants with multiple units can economically be equipped with a synchronizer for each unit.

  2. WOLF; automatic typing program

    USGS Publications Warehouse

    Evenden, G.I.

    1982-01-01

    A FORTRAN IV program for the Hewlett-Packard 1000 series computer provides for automatic typing operations and can, when employed with manufacturer's text editor, provide a system to greatly facilitate preparation of reports, letters and other text. The input text and imbedded control data can perform nearly all of the functions of a typist. A few of the features available are centering, titles, footnotes, indentation, page numbering (including Roman numerals), automatic paragraphing, and two forms of tab operations. This documentation contains both user and technical description of the program.

  3. AUTOMATIC COUNTING APPARATUS

    DOEpatents

    Howell, W.D.

    1957-08-20

    An apparatus for automatically recording the results of counting operations on trains of electrical pulses is described. The disadvantages of prior devices utilizing the two common methods of obtaining the count rate are overcome by this apparatus; in the case of time controlled operation, the disclosed system automatically records amy information stored by the scaler but not transferred to the printer at the end of the predetermined time controlled operations and, in the case of count controlled operation, provision is made to prevent a weak sample from occupying the apparatus for an excessively long period of time.

  4. Automaticity of Conceptual Magnitude

    PubMed Central

    Gliksman, Yarden; Itamar, Shai; Leibovich, Tali; Melman, Yonatan; Henik, Avishai

    2016-01-01

    What is bigger, an elephant or a mouse? This question can be answered without seeing the two animals, since these objects elicit conceptual magnitude. How is an object’s conceptual magnitude processed? It was suggested that conceptual magnitude is automatically processed; namely, irrelevant conceptual magnitude can affect performance when comparing physical magnitudes. The current study further examined this question and aimed to expand the understanding of automaticity of conceptual magnitude. Two different objects were presented and participants were asked to decide which object was larger on the screen (physical magnitude) or in the real world (conceptual magnitude), in separate blocks. By creating congruent (the conceptually larger object was physically larger) and incongruent (the conceptually larger object was physically smaller) pairs of stimuli it was possible to examine the automatic processing of each magnitude. A significant congruity effect was found for both magnitudes. Furthermore, quartile analysis revealed that the congruity was affected similarly by processing time for both magnitudes. These results suggest that the processing of conceptual and physical magnitudes is automatic to the same extent. The results support recent theories suggested that different types of magnitude processing and representation share the same core system. PMID:26879153

  5. Automatic sweep circuit

    DOEpatents

    Keefe, Donald J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found.

  6. Automatic Program Synthesis Reports.

    ERIC Educational Resources Information Center

    Biermann, A. W.; And Others

    Some of the major results of future goals of an automatic program synthesis project are described in the two papers that comprise this document. The first paper gives a detailed algorithm for synthesizing a computer program from a trace of its behavior. Since the algorithm involves a search, the length of time required to do the synthesis of…

  7. Brut: Automatic bubble classifier

    NASA Astrophysics Data System (ADS)

    Beaumont, Christopher; Goodman, Alyssa; Williams, Jonathan; Kendrew, Sarah; Simpson, Robert

    2014-07-01

    Brut, written in Python, identifies bubbles in infrared images of the Galactic midplane; it uses a database of known bubbles from the Milky Way Project and Spitzer images to build an automatic bubble classifier. The classifier is based on the Random Forest algorithm, and uses the WiseRF implementation of this algorithm.

  8. Automatic multiple applicator electrophoresis

    NASA Technical Reports Server (NTRS)

    Grunbaum, B. W.

    1977-01-01

    Easy-to-use, economical device permits electrophoresis on all known supporting media. System includes automatic multiple-sample applicator, sample holder, and electrophoresis apparatus. System has potential applicability to fields of taxonomy, immunology, and genetics. Apparatus is also used for electrofocusing.

  9. Automatic finite element generators

    NASA Technical Reports Server (NTRS)

    Wang, P. S.

    1984-01-01

    The design and implementation of a software system for generating finite elements and related computations are described. Exact symbolic computational techniques are employed to derive strain-displacement matrices and element stiffness matrices. Methods for dealing with the excessive growth of symbolic expressions are discussed. Automatic FORTRAN code generation is described with emphasis on improving the efficiency of the resultant code.

  10. Reactor component automatic grapple

    SciTech Connect

    Greenaway, P.R.

    1982-12-07

    A grapple for handling nuclear reactor components in a medium such as liquid sodium which, upon proper seating and alignment of the grapple with the component as sensed by a mechanical logic integral to the grapple, automatically seizes the component. The mechanical logic system also precludes seizure in the absence of proper seating and alignment.

  11. Reactor component automatic grapple

    DOEpatents

    Greenaway, Paul R.

    1982-01-01

    A grapple for handling nuclear reactor components in a medium such as liquid sodium which, upon proper seating and alignment of the grapple with the component as sensed by a mechanical logic integral to the grapple, automatically seizes the component. The mechanical logic system also precludes seizure in the absence of proper seating and alignment.

  12. Automatic Data Processing Glossary.

    ERIC Educational Resources Information Center

    Bureau of the Budget, Washington, DC.

    The technology of the automatic information processing field has progressed dramatically in the past few years and has created a problem in common term usage. As a solution, "Datamation" Magazine offers this glossary which was compiled by the U.S. Bureau of the Budget as an official reference. The terms appear in a single alphabetic sequence,…

  13. AUTOmatic Message PACKing Facility

    2004-07-01

    AUTOPACK is a library that provides several useful features for programs using the Message Passing Interface (MPI). Features included are: 1. automatic message packing facility 2. management of send and receive requests. 3. management of message buffer memory. 4. determination of the number of anticipated messages from a set of arbitrary sends, and 5. deterministic message delivery for testing purposes.

  14. Fully automatic telemetry data processor

    NASA Technical Reports Server (NTRS)

    Cox, F. B.; Keipert, F. A.; Lee, R. C.

    1968-01-01

    Satellite Telemetry Automatic Reduction System /STARS 2/, a fully automatic computer-controlled telemetry data processor, maximizes data recovery, reduces turnaround time, increases flexibility, and improves operational efficiency. The system incorporates a CDC 3200 computer as its central element.

  15. Automatism and driving offences.

    PubMed

    Rumbold, John

    2013-10-01

    Automatism is a rarely used defence, but it is particularly used for driving offences because many are strict liability offences. Medical evidence is almost always crucial to argue the defence, and it is important to understand the bars that limit the use of automatism so that the important medical issues can be identified. The issue of prior fault is an important public safeguard to ensure that reasonable precautions are taken to prevent accidents. The total loss of control definition is more problematic, especially with disorders of more gradual onset like hypoglycaemic episodes. In these cases the alternative of 'effective loss of control' would be fairer. This article explores several cases, how the criteria were applied to each, and the types of medical assessment required. PMID:24112330

  16. Automatic transmission control method

    SciTech Connect

    Hasegawa, H.; Ishiguro, T.

    1989-07-04

    This patent describes a method of controlling an automatic transmission of an automotive vehicle. The transmission has a gear train which includes a brake for establishing a first lowest speed of the transmission, the brake acting directly on a ring gear which meshes with a pinion, the pinion meshing with a sun gear in a planetary gear train, the ring gear connected with an output member, the sun gear being engageable and disengageable with an input member of the transmission by means of a clutch. The method comprises the steps of: detecting that a shift position of the automatic transmission has been shifted to a neutral range; thereafter introducing hydraulic pressure to the brake if present vehicle velocity is below a predetermined value, whereby the brake is engaged to establish the first lowest speed; and exhausting hydraulic pressure from the brake if present vehicle velocity is higher than a predetermined value, whereby the brake is disengaged.

  17. Automatism and driving offences.

    PubMed

    Rumbold, John

    2013-10-01

    Automatism is a rarely used defence, but it is particularly used for driving offences because many are strict liability offences. Medical evidence is almost always crucial to argue the defence, and it is important to understand the bars that limit the use of automatism so that the important medical issues can be identified. The issue of prior fault is an important public safeguard to ensure that reasonable precautions are taken to prevent accidents. The total loss of control definition is more problematic, especially with disorders of more gradual onset like hypoglycaemic episodes. In these cases the alternative of 'effective loss of control' would be fairer. This article explores several cases, how the criteria were applied to each, and the types of medical assessment required.

  18. Automatic Abstraction in Planning

    NASA Technical Reports Server (NTRS)

    Christensen, J.

    1991-01-01

    Traditionally, abstraction in planning has been accomplished by either state abstraction or operator abstraction, neither of which has been fully automatic. We present a new method, predicate relaxation, for automatically performing state abstraction. PABLO, a nonlinear hierarchical planner, implements predicate relaxation. Theoretical, as well as empirical results are presented which demonstrate the potential advantages of using predicate relaxation in planning. We also present a new definition of hierarchical operators that allows us to guarantee a limited form of completeness. This new definition is shown to be, in some ways, more flexible than previous definitions of hierarchical operators. Finally, a Classical Truth Criterion is presented that is proven to be sound and complete for a planning formalism that is general enough to include most classical planning formalisms that are based on the STRIPS assumption.

  19. Automatic vehicle monitoring

    NASA Technical Reports Server (NTRS)

    Bravman, J. S.; Durrani, S. H.

    1976-01-01

    Automatic vehicle monitoring systems are discussed. In a baseline system for highway applications, each vehicle obtains position information through a Loran-C receiver in rural areas and through a 'signpost' or 'proximity' type sensor in urban areas; the vehicle transmits this information to a central station via a communication link. In an advance system, the vehicle carries a receiver for signals emitted by satellites in the Global Positioning System and uses a satellite-aided communication link to the central station. An advanced railroad car monitoring system uses car-mounted labels and sensors for car identification and cargo status; the information is collected by electronic interrogators mounted along the track and transmitted to a central station. It is concluded that automatic vehicle monitoring systems are technically feasible but not economically feasible unless a large market develops.

  20. Automatic speech recognition

    NASA Astrophysics Data System (ADS)

    Espy-Wilson, Carol

    2005-04-01

    Great strides have been made in the development of automatic speech recognition (ASR) technology over the past thirty years. Most of this effort has been centered around the extension and improvement of Hidden Markov Model (HMM) approaches to ASR. Current commercially-available and industry systems based on HMMs can perform well for certain situational tasks that restrict variability such as phone dialing or limited voice commands. However, the holy grail of ASR systems is performance comparable to humans-in other words, the ability to automatically transcribe unrestricted conversational speech spoken by an infinite number of speakers under varying acoustic environments. This goal is far from being reached. Key to the success of ASR is effective modeling of variability in the speech signal. This tutorial will review the basics of ASR and the various ways in which our current knowledge of speech production, speech perception and prosody can be exploited to improve robustness at every level of the system.

  1. Automatic volume calibration system

    SciTech Connect

    Gates, A.J.; Aaron, C.C.

    1985-05-06

    The Automatic Volume Calibration System presently consists of three independent volume-measurement subsystems and can possibly be expanded to five subsystems. When completed, the system will manually or automatically perform the sequence of valve-control and data-acquisition operations required to measure given volumes. An LSI-11 minicomputer controls the vacuum and pressure sources and controls solenoid control valves to open and close various volumes. The input data are obtained from numerous displacement, temperature, and pressure sensors read by the LSI-11. The LSI-11 calculates the unknown volume from the data acquired during the sequence of valve operations. The results, based on the Ideal Gas Law, also provide information for feedback and control. This paper describes the volume calibration system, its subsystems, and the integration of the various instrumentation used in the system's design and development. 11 refs., 13 figs., 4 tabs.

  2. Automatic Skin Color Beautification

    NASA Astrophysics Data System (ADS)

    Chen, Chih-Wei; Huang, Da-Yuan; Fuh, Chiou-Shann

    In this paper, we propose an automatic skin beautification framework based on color-temperature-insensitive skin-color detection. To polish selected skin region, we apply bilateral filter to smooth the facial flaw. Last, we use Poisson image cloning to integrate the beautified parts into the original input. Experimental results show that the proposed method can be applied in varied light source environment. In addition, this method can naturally beautify the portrait skin.

  3. Automatic payload deployment system

    NASA Astrophysics Data System (ADS)

    Pezeshkian, Narek; Nguyen, Hoa G.; Burmeister, Aaron; Holz, Kevin; Hart, Abraham

    2010-04-01

    The ability to precisely emplace stand-alone payloads in hostile territory has long been on the wish list of US warfighters. This type of activity is one of the main functions of special operation forces, often conducted at great danger. Such risk can be mitigated by transitioning the manual placement of payloads over to an automated placement mechanism by the use of the Automatic Payload Deployment System (APDS). Based on the Automatically Deployed Communication Relays (ADCR) system, which provides non-line-of-sight operation for unmanned ground vehicles by automatically dropping radio relays when needed, the APDS takes this concept a step further and allows for the delivery of a mixed variety of payloads. For example, payloads equipped with a camera and gas sensor in addition to a radio repeater, can be deployed in support of rescue operations of trapped miners. Battlefield applications may include delivering food, ammunition, and medical supplies to the warfighter. Covert operations may require the unmanned emplacement of a network of sensors for human-presence detection, before undertaking the mission. The APDS is well suited for these tasks. Demonstrations have been conducted using an iRobot PackBot EOD in delivering a variety of payloads, for which the performance and results will be discussed in this paper.

  4. Multiple zone catalytic cracking of hydrocarbons

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1992-10-13

    This patent describes a method of cracking a heavy hydrocarbon feedstock and a light hydrocarbon feedstock in a riser reactor, the method producing spent catalyst and regenerated catalyst, the spent and regeneration catalyst comprising a large pore size aluminosilicate zeolite cracking catalyst selected form zeolite Y or USY. It comprises: contacting the light hydrocarbon feedstock with spent catalyst at an initial contact location in the riser; passing a suspension comprising the light hydrocarbon feedstock and the spent catalyst through the riser; introducing the heavy hydrocarbon feedstock into the suspension at a second location downstream of the initial contact location; and introducing the regenerated catalyst into the suspension at a location in the riser downstream of the initial contact location.

  5. Automatic range selector

    DOEpatents

    McNeilly, Clyde E.

    1977-01-04

    A device is provided for automatically selecting from a plurality of ranges of a scale of values to which a meter may be made responsive, that range which encompasses the value of an unknown parameter. A meter relay indicates whether the unknown is of greater or lesser value than the range to which the meter is then responsive. The rotatable part of a stepping relay is rotated in one direction or the other in response to the indication from the meter relay. Various positions of the rotatable part are associated with particular scales. Switching means are sensitive to the position of the rotatable part to couple the associated range to the meter.

  6. AUTOMATIC FREQUENCY CONTROL SYSTEM

    DOEpatents

    Hansen, C.F.; Salisbury, J.D.

    1961-01-10

    A control is described for automatically matching the frequency of a resonant cavity to that of a driving oscillator. The driving oscillator is disconnected from the cavity and a secondary oscillator is actuated in which the cavity is the frequency determining element. A low frequency is mixed with the output of the driving oscillator and the resultant lower and upper sidebands are separately derived. The frequencies of the sidebands are compared with the secondary oscillator frequency. deriving a servo control signal to adjust a tuning element in the cavity and matching the cavity frequency to that of the driving oscillator. The driving oscillator may then be connected to the cavity.

  7. Automatic level control circuit

    NASA Technical Reports Server (NTRS)

    Toole, P. C.; Mccarthy, D. M. (Inventor)

    1983-01-01

    An automatic level control circuit for an operational amplifier for minimizing spikes or instantaneous gain of the amplifier at a low period wherein no signal is received on the input is provided. The apparatus includes a multibranch circuit which is connected between an output terminal and a feedback terminal. A pair of zener diodes are connected back to back in series with a capacitor provided in one of the branches. A pair of voltage dividing resistors are connected in another of the branches and a second capacitor is provided in the remaining branch of controlling the high frequency oscillations of the operational amplifier.

  8. Automatic readout micrometer

    DOEpatents

    Lauritzen, T.

    A measuring system is described for surveying and very accurately positioning objects with respect to a reference line. A principle use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse of fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.

  9. Automatic readout micrometer

    DOEpatents

    Lauritzen, Ted

    1982-01-01

    A measuring system is disclosed for surveying and very accurately positioning objects with respect to a reference line. A principal use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse or fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.

  10. Automatic temperature control

    SciTech Connect

    Sheridan, J.P.

    1986-07-22

    An automatic temperature control system is described for maintaining a preset temperature in an enclosed space in a building, comprising: heating and cooling means for conditioning the air in the enclosed space to maintain the preset temperature; exterior thermostat means outside the building for sensing ambient exterior temperature levels; interior thermostat means in the enclosed space, preset to the preset temperature to be maintained and connected with the heating and cooling means to energize the means for heating or cooling, as appropriate, when the preset temperature is reached; means defining a heat sink containing a volume of air heated by solar radiation, the volume of the heat sink being such that the temperature level therein is not affected by minor or temporary ambient temperature fluctuations; and heat sink thermostat means in the heat sink sensing the temperature in the heat sink, the heat sink thermostat means being connected in tandem with the exterior thermostat means and operative with the exterior thermostat means to switch the interior thermostat means to either a first readiness state for heating or a second readiness state for cooling, depending upon which mode is indicated by both the exterior and heat sink thermostat means, whereby the system automatically switches between heating and cooling, as required, in response to a comparison of exterior and heat sink temperatures.

  11. Comparison of automatic control systems

    NASA Technical Reports Server (NTRS)

    Oppelt, W

    1941-01-01

    This report deals with a reciprocal comparison of an automatic pressure control, an automatic rpm control, an automatic temperature control, and an automatic directional control. It shows the difference between the "faultproof" regulator and the actual regulator which is subject to faults, and develops this difference as far as possible in a parallel manner with regard to the control systems under consideration. Such as analysis affords, particularly in its extension to the faults of the actual regulator, a deep insight into the mechanism of the regulator process.

  12. Automatism, medicine and the law.

    PubMed

    Fenwick, P

    1990-01-01

    The law on automatism is undergoing change. For some time there has been a conflict between the medical and the legal views. The medical profession believes that the present division between sane and insane automatism makes little medical sense. Insane automatism is due to an internal factor, that is, a disease of the brain, while sane automatism is due to an external factor, such as a blow on the head or an injection of a drug. This leads to the situation where, for example, the hypoglycaemia resulting from injected insulin would be sane automatism, while hypoglycaemia while results from an islet tumour would be insane automatism. This would not matter if the consequences were the same. However, sane automatism leads to an acquittal, whereas insane automatism leads to committal to a secure mental hospital. This article traces the development of the concept of automatism in the 1950s to the present time, and looks at the anomalies in the law as it now stands. It considers the medical conditions of, and the law relating to, epilepsy, alcohol and drug automatism, hypoglycaemic automatisms, transient global amnesia, and hysterical automatisms. Sleep automatisms, and offences committed during a somnambulistic automatism, are also discussed in detail. The article also examines the need of the Courts to be provided with expert evidence and the role that the qualified medical practitioner should take. It clarifies the various points which medical practitioners should consider when assessing whether a defence of automatism is justified on medical grounds, and in seeking to establish such a defence. The present law is unsatisfactory, as it does not allow any discretion in sentencing on the part of the judge once a verdict of not guilty by virtue of insane automatism has been passed. The judge must sentence the defendant to detention in a secure mental hospital. This would certainly be satisfactory where violent crimes have been committed. However, it is inappropriate in

  13. Automatic dynamic mask extraction for PIV images containing an unsteady interface, bubbles, and a moving structure

    NASA Astrophysics Data System (ADS)

    Dussol, David; Druault, Philippe; Mallat, Bachar; Delacroix, Sylvain; Germain, Grégory

    2016-07-01

    When performing Particle Image Velocimetry (PIV) measurements in complex fluid flows with moving interfaces and a two-phase flow, it is necessary to develop a mask to remove non-physical measurements. This is the case when studying, for example, the complex bubble sweep-down phenomenon observed in oceanographic research vessels. Indeed, in such a configuration, the presence of an unsteady free surface, of a solid-liquid interface and of bubbles in the PIV frame, leads to generate numerous laser reflections and therefore spurious velocity vectors. In this note, an image masking process is developed to successively identify the boundaries of the ship and the free surface interface. As the presence of the solid hull surface induces laser reflections, the hull edge contours are simply detected in the first PIV frame and dynamically estimated for consecutive ones. As for the unsteady surface determination, a specific process is implemented like the following: i) the edge detection of the gradient magnitude in the PIV frame, ii) the extraction of the particles by filtering high-intensity large areas related to the bubbles and/or hull reflections, iii) the extraction of the rough region containing these particles and their reflections, iv) the removal of these reflections. The unsteady surface is finally obtained with a fifth-order polynomial interpolation. The resulted free surface is successfully validated from the Fourier analysis and by visualizing selected PIV images containing numerous spurious high intensity areas. This paper demonstrates how this data analysis process leads to PIV images database without reflections and an automatic detection of both the free surface and the rigid body. An application of this new mask is finally detailed, allowing a preliminary analysis of the hydrodynamic flow.

  14. Automatic MR volume registration and its evaluation for the pelvis and prostate

    NASA Astrophysics Data System (ADS)

    Fei, Baowei; Wheaton, Andrew; Lee, Zhenghong; Duerk, Jeffrey L.; Wilson, David L.

    2002-03-01

    A three-dimensional (3D) mutual information registration method was created and used to register MRI volumes of the pelvis and prostate. It had special features to improve robustness. First, it used a multi-resolution approach and performed registration from low to high resolution. Second, it used two similarity measures, correlation coefficient at lower resolutions and mutual information at full resolution, because of their particular advantages. Third, we created a method to avoid local minima by restarting the registration with randomly perturbed parameters. The criterion for restarting was a correlation coefficient below an empirically determined threshold. Experiments determined the accuracy of registration under conditions found in potential applications in prostate cancer diagnosis, staging, treatment and interventional MRI (iMRI) guided therapies. Images were acquired in the diagnostic (supine) and treatment position (supine with legs raised). Images were also acquired as a function of bladder filling and the time interval between imaging sessions. Overall studies on three patients and three healthy volunteers, when both volumes in a pair were obtained in the diagnostic position under comparable conditions, bony landmarks and prostate 3D centroids were aligned within 1.6 +/- 0.2 mm and 1.4 +/- 0.2 mm, respectively, values only slightly larger than a voxel. Analysis suggests that actual errors are smaller because of the uncertainty in landmark localization and prostate segmentation. Between the diagnostic and treatment positions, bony landmarks continued to register well, but prostate centroids moved towards the posterior 2.8-3.4 mm. Manual cropping to remove voxels in the legs was necessary to register these images. In conclusion, automatic, rigid body registration is probably sufficiently accurate for many applications in prostate cancer. For potential iMRI-guided treatments, the small prostate displacement between the diagnostic and treatment positions

  15. Automatic routing module

    NASA Technical Reports Server (NTRS)

    Malin, Janice A.

    1987-01-01

    Automatic Routing Module (ARM) is a tool to partially automate Air Launched Cruise Missile (ALCM) routing. For any accessible launch point or target pair, ARM creates flyable routes that, within the fidelity of the models, are optimal in terms of threat avoidance, clobber avoidance, and adherence to vehicle and planning constraints. Although highly algorithmic, ARM is an expert system. Because of the heuristics applied, ARM generated routes closely resemble manually generated routes in routine cases. In more complex cases, ARM's ability to accumulate and assess threat danger in three dimensions and trade that danger off with the probability of ground clobber results in the safest path around or through difficult areas. The tools available prior to ARM did not provide the planner with enough information or present it in such a way that ensured he would select the safest path.

  16. AUTOMATIC HAND COUNTER

    DOEpatents

    Mann J.R.; Wainwright, A.E.

    1963-06-11

    An automatic, personnel-operated, alpha-particle hand monitor is described which functions as a qualitative instrument to indicate to the person using it whether his hands are cold'' or hot.'' The monitor is activated by a push button and includes several capacitor-triggered thyratron tubes. Upon release of the push button, the monitor starts the counting of the radiation present on the hands of the person. If the count of the radiation exceeds a predetermined level within a predetermined time, then a capacitor will trigger a first thyratron tube to light a hot'' lamp. If, however, the count is below such level during this time period, another capacitor will fire a second thyratron to light a safe'' lamp. (AEC)

  17. Automatic thermal switch

    NASA Technical Reports Server (NTRS)

    Wing, L. D.; Cunningham, J. W. (Inventor)

    1981-01-01

    An automatic thermal switch to control heat flow includes a first thermally conductive plate, a second thermally conductive plate and a thermal transfer plate pivotally mounted between the first and second plates. A phase change power unit, including a plunger connected to the transfer plate, is in thermal contact with the first thermally conductive plate. A biasing element, connected to the transfer plate, biases the transfer plate in a predetermined position with respect to the first and second plates. When the phase change power unit is actuated by an increase in heat transmitted through the first plate, the plunger extends and pivots the transfer plate to vary the thermal conduction between the first and second plates through the transfer plate. The biasing element, transfer plate and piston can be arranged to provide either a normally closed or normally open thermally conductive path between the first and second plates.

  18. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-07-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanisms, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  19. Automatic alkaloid removal system.

    PubMed

    Yahaya, Muhammad Rizuwan; Hj Razali, Mohd Hudzari; Abu Bakar, Che Abdullah; Ismail, Wan Ishak Wan; Muda, Wan Musa Wan; Mat, Nashriyah; Zakaria, Abd

    2014-01-01

    This alkaloid automated removal machine was developed at Instrumentation Laboratory, Universiti Sultan Zainal Abidin Malaysia that purposely for removing the alkaloid toxicity from Dioscorea hispida (DH) tuber. It is a poisonous plant where scientific study has shown that its tubers contain toxic alkaloid constituents, dioscorine. The tubers can only be consumed after it poisonous is removed. In this experiment, the tubers are needed to blend as powder form before inserting into machine basket. The user is need to push the START button on machine controller for switching the water pump ON by then creating turbulence wave of water in machine tank. The water will stop automatically by triggering the outlet solenoid valve. The powders of tubers are washed for 10 minutes while 1 liter of contaminated water due toxin mixture is flowing out. At this time, the controller will automatically triggered inlet solenoid valve and the new water will flow in machine tank until achieve the desire level that which determined by ultra sonic sensor. This process will repeated for 7 h and the positive result is achieved and shows it significant according to the several parameters of biological character ofpH, temperature, dissolve oxygen, turbidity, conductivity and fish survival rate or time. From that parameter, it also shows the positive result which is near or same with control water and assuming was made that the toxin is fully removed when the pH of DH powder is near with control water. For control water, the pH is about 5.3 while water from this experiment process is 6.0 and before run the machine the pH of contaminated water is about 3.8 which are too acid. This automated machine can save time for removing toxicity from DH compared with a traditional method while less observation of the user. PMID:24783795

  20. Automatic Coal-Mining System

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1985-01-01

    Coal cutting and removal done with minimal hazard to people. Automatic coal mine cutting, transport and roof-support movement all done by automatic machinery. Exposure of people to hazardous conditions reduced to inspection tours, maintenance, repair, and possibly entry mining.

  1. Automatic Indexing of Full Texts.

    ERIC Educational Resources Information Center

    Jonak, Zdenek

    1984-01-01

    Demonstrates efficiency of preparation of query description using semantic analyser method based on analysis of semantic structure of documents in field of automatic indexing. Results obtained are compared with automatic indexing results performed by traditional methods and results of indexing done by human indexers. Sample terms and codes are…

  2. Automatic Command Sequence Generation

    NASA Technical Reports Server (NTRS)

    Fisher, Forest; Gladded, Roy; Khanampompan, Teerapat

    2007-01-01

    Automatic Sequence Generator (Autogen) Version 3.0 software automatically generates command sequences for the Mars Reconnaissance Orbiter (MRO) and several other JPL spacecraft operated by the multi-mission support team. Autogen uses standard JPL sequencing tools like APGEN, ASP, SEQGEN, and the DOM database to automate the generation of uplink command products, Spacecraft Command Message Format (SCMF) files, and the corresponding ground command products, DSN Keywords Files (DKF). Autogen supports all the major multi-mission mission phases including the cruise, aerobraking, mapping/science, and relay mission phases. Autogen is a Perl script, which functions within the mission operations UNIX environment. It consists of two parts: a set of model files and the autogen Perl script. Autogen encodes the behaviors of the system into a model and encodes algorithms for context sensitive customizations of the modeled behaviors. The model includes knowledge of different mission phases and how the resultant command products must differ for these phases. The executable software portion of Autogen, automates the setup and use of APGEN for constructing a spacecraft activity sequence file (SASF). The setup includes file retrieval through the DOM (Distributed Object Manager), an object database used to store project files. This step retrieves all the needed input files for generating the command products. Depending on the mission phase, Autogen also uses the ASP (Automated Sequence Processor) and SEQGEN to generate the command product sent to the spacecraft. Autogen also provides the means for customizing sequences through the use of configuration files. By automating the majority of the sequencing generation process, Autogen eliminates many sequence generation errors commonly introduced by manually constructing spacecraft command sequences. Through the layering of commands into the sequence by a series of scheduling algorithms, users are able to rapidly and reliably construct the

  3. Electronically controlled automatic transmission

    SciTech Connect

    Ohkubo, M.; Shiba, H.; Nakamura, K.

    1989-03-28

    This patent describes an electronically controlled automatic transmission having a manual valve working in connection with a manual shift lever, shift valves operated by solenoid valves which are driven by an electronic control circuit previously memorizing shift patterns, and a hydraulic circuit controlled by these manual valve and shift valves for driving brakes and a clutch in order to change speed. Shift patterns of 2-range and L-range, in addition to a shift pattern of D-range, are memorized previously in the electronic control circuit, an operation switch is provided which changes the shift pattern of the electronic control circuit to any shift pattern among those of D-range, 2-range and L-range at time of the manual shift lever being in a D-range position, a releasable lock mechanism is provided which prevents the manual shift lever from entering 2-range and L-range positions, and the hydraulic circuit is set to a third speed mode when the manual shift lever is in the D-range position. The circuit is set to a second speed mode when it is in the 2-range position, and the circuit is set to a first speed mode when it is in the L-range position, respectively, in case where the shift valves are not working.

  4. Automatic Welding System

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Robotic welding has been of interest to industrial firms because it offers higher productivity at lower cost than manual welding. There are some systems with automated arc guidance available, but they have disadvantages, such as limitations on types of materials or types of seams that can be welded; susceptibility to stray electrical signals; restricted field of view; or tendency to contaminate the weld seam. Wanting to overcome these disadvantages, Marshall Space Flight Center, aided by Hayes International Corporation, developed system that uses closed-circuit TV signals for automatic guidance of the welding torch. NASA granted license to Combined Technologies, Inc. for commercial application of the technology. They developed a refined and improved arc guidance system. CTI in turn, licensed the Merrick Corporation, also of Nashville, for marketing and manufacturing of the new system, called the CT2 Optical Trucker. CT2 is a non-contracting system that offers adaptability to broader range of welding jobs and provides greater reliability in high speed operation. It is extremely accurate and can travel at high speed of up to 150 inches per minute.

  5. Automatic transmission system

    SciTech Connect

    Ha, J.S.

    1989-04-25

    An automatic transmission system is described for use in vehicles, which comprises: a clutch wheel containing a plurality of concentric rings of decreasing diameter, the clutch wheel being attached to an engine of the vehicle; a plurality of clutch gears corresponding in size to the concentric rings, the clutch gears being adapted to selectively and frictionally engage with the concentric rings of the clutch wheel; an accelerator pedal and a gear selector, the accelerator pedals being connected to one end of a substantially U-shaped frame member, the other end of the substantially U-shaped frame member selectively engaging with one end of one of wires received in a pair of apertures of the gear selector; a plurality of drive gear controllers and a reverse gear controller; means operatively connected with the gear selector and the plurality of drive gear controllers and reverse gear controller for selectively engaging one of the drive and reverse gear controllers depending upon the position of the gear selector; and means for individually connecting the drive and reverse gear controllers with the corresponding clutch gears whereby upon the selection of the gear selector, friction engagement is achieved between the clutch gear and the clutch wheels for rotating the wheel in the forward or reverse direction.

  6. Attaining Automaticity in the Visual Numerosity Task is Not Automatic

    PubMed Central

    Speelman, Craig P.; Muller Townsend, Katrina L.

    2015-01-01

    This experiment is a replication of experiments reported by Lassaline and Logan (1993) using the visual numerosity task. The aim was to replicate the transition from controlled to automatic processing reported by Lassaline and Logan (1993), and to examine the extent to which this result, reported with average group results, can be observed in the results of individuals within a group. The group results in this experiment did replicate those reported by Lassaline and Logan (1993); however, one half of the sample did not attain automaticity with the task, and one-third did not exhibit a transition from controlled to automatic processing. These results raise questions about the pervasiveness of automaticity, and the interpretation of group means when examining cognitive processes. PMID:26635658

  7. Automatic transmission apparatus

    SciTech Connect

    Hiketa, M.

    1987-10-06

    An automatic transmission apparatus is described comprising: an input shaft, an output shaft disposed behind and coaxially with the input shaft, a counter shaft disposed substantially parallel to both of the input and output shafts, a first gear train including a first gear provided on the input shaft and a second gear provided on the counter shaft to be meshed with the first gear so as to form a first power transmitting path, first friction clutch means operative selectively to make and break the first power transmitting path, a second gear train including a third gear provided through one-way clutch means on a rear end portion of the input shaft and a fourth gear provided on the counter shaft to be meshed with the third gear so as to form a second power transmitting path, second friction clutch means provided at a front end portion of the output shaft, a third gear train including a fifth gear provided on a rear end portion of the counter shaft and a sixth gear provided on the output shaft to be meshed with the fifth gear so as to form a fourth power transmitting path, third friction clutch means operative selectively to make and break the fourth power transmitting path, fourth friction clutch means operative selectively to make and break the second power transmitting path, a fourth gear train including a seventh gear provided on the counter shaft and an eighth gear provided on the output shaft and fifth friction clutch means operative selectively to make and break the fifth power transmitting path.

  8. Clothes Dryer Automatic Termination Evaluation

    SciTech Connect

    TeGrotenhuis, Ward E.

    2014-10-01

    Volume 2: Improved Sensor and Control Designs Many residential clothes dryers on the market today provide automatic cycles that are intended to stop when the clothes are dry, as determined by the final remaining moisture content (RMC). However, testing of automatic termination cycles has shown that many dryers are susceptible to over-drying of loads, leading to excess energy consumption. In particular, tests performed using the DOE Test Procedure in Appendix D2 of 10 CFR 430 subpart B have shown that as much as 62% of the energy used in a cycle may be from over-drying. Volume 1 of this report shows an average of 20% excess energy from over-drying when running automatic cycles with various load compositions and dryer settings. Consequently, improving automatic termination sensors and algorithms has the potential for substantial energy savings in the U.S.

  9. Automatic programming of simulation models

    NASA Technical Reports Server (NTRS)

    Schroer, Bernard J.; Tseng, Fan T.; Zhang, Shou X.; Dwan, Wen S.

    1988-01-01

    The objective of automatic programming is to improve the overall environment for describing the program. This improved environment is realized by a reduction in the amount of detail that the programmer needs to know and is exposed to. Furthermore, this improved environment is achieved by a specification language that is more natural to the user's problem domain and to the user's way of thinking and looking at the problem. The goal of this research is to apply the concepts of automatic programming (AP) to modeling discrete event simulation system. Specific emphasis is on the design and development of simulation tools to assist the modeler define or construct a model of the system and to then automatically write the corresponding simulation code in the target simulation language, GPSS/PC. A related goal is to evaluate the feasibility of various languages for constructing automatic programming simulation tools.

  10. Automatic safety rod for reactors

    DOEpatents

    Germer, John H.

    1988-01-01

    An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-core flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

  11. Prospects for de-automatization.

    PubMed

    Kihlstrom, John F

    2011-06-01

    Research by Raz and his associates has repeatedly found that suggestions for hypnotic agnosia, administered to highly hypnotizable subjects, reduce or even eliminate Stroop interference. The present paper sought unsuccessfully to extend these findings to negative priming in the Stroop task. Nevertheless, the reduction of Stroop interference has broad theoretical implications, both for our understanding of automaticity and for the prospect of de-automatizing cognition in meditation and other altered states of consciousness.

  12. Automatic Collision Avoidance Technology (ACAT)

    NASA Technical Reports Server (NTRS)

    Swihart, Donald E.; Skoog, Mark A.

    2007-01-01

    This document represents two views of the Automatic Collision Avoidance Technology (ACAT). One viewgraph presentation reviews the development and system design of Automatic Collision Avoidance Technology (ACAT). Two types of ACAT exist: Automatic Ground Collision Avoidance (AGCAS) and Automatic Air Collision Avoidance (AACAS). The AGCAS Uses Digital Terrain Elevation Data (DTED) for mapping functions, and uses Navigation data to place aircraft on map. It then scans DTED in front of and around aircraft and uses future aircraft trajectory (5g) to provide automatic flyup maneuver when required. The AACAS uses data link to determine position and closing rate. It contains several canned maneuvers to avoid collision. Automatic maneuvers can occur at last instant and both aircraft maneuver when using data link. The system can use sensor in place of data link. The second viewgraph presentation reviews the development of a flight test and an evaluation of the test. A review of the operation and comparison of the AGCAS and a pilot's performance are given. The same review is given for the AACAS is given.

  13. Automatic rapid attachable warhead section

    DOEpatents

    Trennel, Anthony J.

    1994-05-10

    Disclosed are a method and apparatus for (1) automatically selecting warheads or reentry vehicles from a storage area containing a plurality of types of warheads or reentry vehicles, (2) automatically selecting weapon carriers from a storage area containing at least one type of weapon carrier, (3) manipulating and aligning the selected warheads or reentry vehicles and weapon carriers, and (4) automatically coupling the warheads or reentry vehicles with the weapon carriers such that coupling of improperly selected warheads or reentry vehicles with weapon carriers is inhibited. Such inhibition enhances safety of operations and is achieved by a number of means including computer control of the process of selection and coupling and use of connectorless interfaces capable of assuring that improperly selected items will be rejected or rendered inoperable prior to coupling. Also disclosed are a method and apparatus wherein the stated principles pertaining to selection, coupling and inhibition are extended to apply to any item-to-be-carried and any carrying assembly.

  14. Automatic rapid attachable warhead section

    DOEpatents

    Trennel, A.J.

    1994-05-10

    Disclosed are a method and apparatus for automatically selecting warheads or reentry vehicles from a storage area containing a plurality of types of warheads or reentry vehicles, automatically selecting weapon carriers from a storage area containing at least one type of weapon carrier, manipulating and aligning the selected warheads or reentry vehicles and weapon carriers, and automatically coupling the warheads or reentry vehicles with the weapon carriers such that coupling of improperly selected warheads or reentry vehicles with weapon carriers is inhibited. Such inhibition enhances safety of operations and is achieved by a number of means including computer control of the process of selection and coupling and use of connectorless interfaces capable of assuring that improperly selected items will be rejected or rendered inoperable prior to coupling. Also disclosed are a method and apparatus wherein the stated principles pertaining to selection, coupling and inhibition are extended to apply to any item-to-be-carried and any carrying assembly. 10 figures.

  15. Automatic analysis of macroarrays images.

    PubMed

    Caridade, C R; Marcal, A S; Mendonca, T; Albuquerque, P; Mendes, M V; Tavares, F

    2010-01-01

    The analysis of dot blot (macroarray) images is currently based on the human identification of positive/negative dots, which is a subjective and time consuming process. This paper presents a system for the automatic analysis of dot blot images, using a pre-defined grid of markers, including a number of ON and OFF controls. The geometric deformations of the input image are corrected, and the individual markers detected, both tasks fully automatically. Based on a previous training stage, the probability for each marker to be ON is established. This information is provided together with quality parameters for training, noise and classification, allowing for a fully automatic evaluation of a dot blot image. PMID:21097139

  16. Automatic programming of simulation models

    NASA Technical Reports Server (NTRS)

    Schroer, Bernard J.; Tseng, Fan T.; Zhang, Shou X.; Dwan, Wen S.

    1990-01-01

    The concepts of software engineering were used to improve the simulation modeling environment. Emphasis was placed on the application of an element of rapid prototyping, or automatic programming, to assist the modeler define the problem specification. Then, once the problem specification has been defined, an automatic code generator is used to write the simulation code. The following two domains were selected for evaluating the concepts of software engineering for discrete event simulation: manufacturing domain and a spacecraft countdown network sequence. The specific tasks were to: (1) define the software requirements for a graphical user interface to the Automatic Manufacturing Programming System (AMPS) system; (2) develop a graphical user interface for AMPS; and (3) compare the AMPS graphical interface with the AMPS interactive user interface.

  17. Grinding Parts For Automatic Welding

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.; Hoult, William S.

    1989-01-01

    Rollers guide grinding tool along prospective welding path. Skatelike fixture holds rotary grinder or file for machining large-diameter rings or ring segments in preparation for welding. Operator grasps handles to push rolling fixture along part. Rollers maintain precise dimensional relationship so grinding wheel cuts precise depth. Fixture-mounted grinder machines surface to quality sufficient for automatic welding; manual welding with attendant variations and distortion not necessary. Developed to enable automatic welding of parts, manual welding of which resulted in weld bead permeated with microscopic fissures.

  18. Automatic interpretation of Schlumberger soundings

    SciTech Connect

    Ushijima, K.

    1980-09-01

    The automatic interpretation of apparent resistivity curves from horizontally layered earth models is carried out by the curve-fitting method in three steps: (1) the observed VES data are interpolated at equidistant points of electrode separations on the logarithmic scale by using the cubic spline function, (2) the layer parameters which are resistivities and depths are predicted from the sampled apparent resistivity values by SALS system program and (3) the theoretical VES curves from the models are calculated by Ghosh's linear filter method using the Zhody's computer program. Two soundings taken over Takenoyu geothermal area were chosen to test the procedures of the automatic interpretation.

  19. Algorithms for skiascopy measurement automatization

    NASA Astrophysics Data System (ADS)

    Fomins, Sergejs; Trukša, Renārs; KrūmiĆa, Gunta

    2014-10-01

    Automatic dynamic infrared retinoscope was developed, which allows to run procedure at a much higher rate. Our system uses a USB image sensor with up to 180 Hz refresh rate equipped with a long focus objective and 850 nm infrared light emitting diode as light source. Two servo motors driven by microprocessor control the rotation of semitransparent mirror and motion of retinoscope chassis. Image of eye pupil reflex is captured via software and analyzed along the horizontal plane. Algorithm for automatic accommodative state analysis is developed based on the intensity changes of the fundus reflex.

  20. Traduction automatique et terminologie automatique (Automatic Translation and Automatic Terminology

    ERIC Educational Resources Information Center

    Dansereau, Jules

    1978-01-01

    An exposition of reasons why a system of automatic translation could not use a terminology bank except as a source of information. The fundamental difference between the two tools is explained and examples of translation and mistranslation are given as evidence of the limits and possibilities of each process. (Text is in French.) (AMH)

  1. Automatic Error Analysis Using Intervals

    ERIC Educational Resources Information Center

    Rothwell, E. J.; Cloud, M. J.

    2012-01-01

    A technique for automatic error analysis using interval mathematics is introduced. A comparison to standard error propagation methods shows that in cases involving complicated formulas, the interval approach gives comparable error estimates with much less effort. Several examples are considered, and numerical errors are computed using the INTLAB…

  2. Automatic 35 mm slide duplicator

    NASA Technical Reports Server (NTRS)

    Seidel, H. F.; Texler, R. E.

    1980-01-01

    Automatic duplicator is readily assembled from conventional, inexpensive equipment and parts. Series of slides can be exposed without operator attention, eliminating considerable manual handling and processing ordinarily required. At end of programmed exposure sequence, unit shuts off and audible alarm signals completion of process.

  3. Bubble vector in automatic merging

    NASA Technical Reports Server (NTRS)

    Pamidi, P. R.; Butler, T. G.

    1987-01-01

    It is shown that it is within the capability of the DMAP language to build a set of vectors that can grow incrementally to be applied automatically and economically within a DMAP loop that serves to append sub-matrices that are generated within a loop to a core matrix. The method of constructing such vectors is explained.

  4. Automatically Preparing Safe SQL Queries

    NASA Astrophysics Data System (ADS)

    Bisht, Prithvi; Sistla, A. Prasad; Venkatakrishnan, V. N.

    We present the first sound program source transformation approach for automatically transforming the code of a legacy web application to employ PREPARE statements in place of unsafe SQL queries. Our approach therefore opens the way for eradicating the SQL injection threat vector from legacy web applications.

  5. Graphonomics, Automaticity and Handwriting Assessment

    ERIC Educational Resources Information Center

    Tucha, Oliver; Tucha, Lara; Lange, Klaus W.

    2008-01-01

    A recent review of handwriting research in "Literacy" concluded that current curricula of handwriting education focus too much on writing style and neatness and neglect the aspect of handwriting automaticity. This conclusion is supported by evidence in the field of graphonomic research, where a range of experiments have been used to investigate…

  6. Automatic Identification of Metaphoric Utterances

    ERIC Educational Resources Information Center

    Dunn, Jonathan Edwin

    2013-01-01

    This dissertation analyzes the problem of metaphor identification in linguistic and computational semantics, considering both manual and automatic approaches. It describes a manual approach to metaphor identification, the Metaphoricity Measurement Procedure (MMP), and compares this approach with other manual approaches. The dissertation then…

  7. Automatic marker for photographic film

    NASA Technical Reports Server (NTRS)

    Gabbard, N. M.; Surrency, W. M.

    1974-01-01

    Commercially-produced wire-marking machine is modified to title or mark film rolls automatically. Machine is used with film drive mechanism which is powered with variable-speed, 28-volt dc motor. Up to 40 frames per minute can be marked, reducing time and cost of process.

  8. How automatic are crossmodal correspondences?

    PubMed

    Spence, Charles; Deroy, Ophelia

    2013-03-01

    The last couple of years have seen a rapid growth of interest (especially amongst cognitive psychologists, cognitive neuroscientists, and developmental researchers) in the study of crossmodal correspondences - the tendency for our brains (not to mention the brains of other species) to preferentially associate certain features or dimensions of stimuli across the senses. By now, robust empirical evidence supports the existence of numerous crossmodal correspondences, affecting people's performance across a wide range of psychological tasks - in everything from the redundant target effect paradigm through to studies of the Implicit Association Test, and from speeded discrimination/classification tasks through to unspeeded spatial localisation and temporal order judgment tasks. However, one question that has yet to receive a satisfactory answer is whether crossmodal correspondences automatically affect people's performance (in all, or at least in a subset of tasks), as opposed to reflecting more of a strategic, or top-down, phenomenon. Here, we review the latest research on the topic of crossmodal correspondences to have addressed this issue. We argue that answering the question will require researchers to be more precise in terms of defining what exactly automaticity entails. Furthermore, one's answer to the automaticity question may also hinge on the answer to a second question: Namely, whether crossmodal correspondences are all 'of a kind', or whether instead there may be several different kinds of crossmodal mapping (e.g., statistical, structural, and semantic). Different answers to the automaticity question may then be revealed depending on the type of correspondence under consideration. We make a number of suggestions for future research that might help to determine just how automatic crossmodal correspondences really are. PMID:23370382

  9. Robust methods for automatic image-to-world registration in cone-beam CT interventional guidance

    SciTech Connect

    Dang, H.; Otake, Y.; Schafer, S.; Stayman, J. W.; Kleinszig, G.; Siewerdsen, J. H.

    2012-10-15

    Purpose: Real-time surgical navigation relies on accurate image-to-world registration to align the coordinate systems of the image and patient. Conventional manual registration can present a workflow bottleneck and is prone to manual error and intraoperator variability. This work reports alternative means of automatic image-to-world registration, each method involving an automatic registration marker (ARM) used in conjunction with C-arm cone-beam CT (CBCT). The first involves a Known-Model registration method in which the ARM is a predefined tool, and the second is a Free-Form method in which the ARM is freely configurable. Methods: Studies were performed using a prototype C-arm for CBCT and a surgical tracking system. A simple ARM was designed with markers comprising a tungsten sphere within infrared reflectors to permit detection of markers in both x-ray projections and by an infrared tracker. The Known-Model method exercised a predefined specification of the ARM in combination with 3D-2D registration to estimate the transformation that yields the optimal match between forward projection of the ARM and the measured projection images. The Free-Form method localizes markers individually in projection data by a robust Hough transform approach extended from previous work, backprojected to 3D image coordinates based on C-arm geometric calibration. Image-domain point sets were transformed to world coordinates by rigid-body point-based registration. The robustness and registration accuracy of each method was tested in comparison to manual registration across a range of body sites (head, thorax, and abdomen) of interest in CBCT-guided surgery, including cases with interventional tools in the radiographic scene. Results: The automatic methods exhibited similar target registration error (TRE) and were comparable or superior to manual registration for placement of the ARM within {approx}200 mm of C-arm isocenter. Marker localization in projection data was robust across all

  10. Robust methods for automatic image-to-world registration in cone-beam CT interventional guidance

    PubMed Central

    Dang, H.; Otake, Y.; Schafer, S.; Stayman, J. W.; Kleinszig, G.; Siewerdsen, J. H.

    2012-01-01

    Purpose: Real-time surgical navigation relies on accurate image-to-world registration to align the coordinate systems of the image and patient. Conventional manual registration can present a workflow bottleneck and is prone to manual error and intraoperator variability. This work reports alternative means of automatic image-to-world registration, each method involving an automatic registration marker (ARM) used in conjunction with C-arm cone-beam CT (CBCT). The first involves a Known-Model registration method in which the ARM is a predefined tool, and the second is a Free-Form method in which the ARM is freely configurable. Methods: Studies were performed using a prototype C-arm for CBCT and a surgical tracking system. A simple ARM was designed with markers comprising a tungsten sphere within infrared reflectors to permit detection of markers in both x-ray projections and by an infrared tracker. The Known-Model method exercised a predefined specification of the ARM in combination with 3D-2D registration to estimate the transformation that yields the optimal match between forward projection of the ARM and the measured projection images. The Free-Form method localizes markers individually in projection data by a robust Hough transform approach extended from previous work, backprojected to 3D image coordinates based on C-arm geometric calibration. Image-domain point sets were transformed to world coordinates by rigid-body point-based registration. The robustness and registration accuracy of each method was tested in comparison to manual registration across a range of body sites (head, thorax, and abdomen) of interest in CBCT-guided surgery, including cases with interventional tools in the radiographic scene. Results: The automatic methods exhibited similar target registration error (TRE) and were comparable or superior to manual registration for placement of the ARM within ∼200 mm of C-arm isocenter. Marker localization in projection data was robust across all

  11. Auxiliary circuit enables automatic monitoring of EKG'S

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Auxiliary circuits allow direct, automatic monitoring of electrocardiograms by digital computers. One noiseless square-wave output signal for each trigger pulse from an electrocardiogram preamplifier is produced. The circuit also permits automatic processing of cardiovascular data from analog tapes.

  12. Automatisms: bridging clinical neurology with criminal law.

    PubMed

    Rolnick, Joshua; Parvizi, Josef

    2011-03-01

    The law, like neurology, grapples with the relationship between disease states and behavior. Sometimes, the two disciplines share the same terminology, such as automatism. In law, the "automatism defense" is a claim that action was involuntary or performed while unconscious. Someone charged with a serious crime can acknowledge committing the act and yet may go free if, relying on the expert testimony of clinicians, the court determines that the act of crime was committed in a state of automatism. In this review, we explore the relationship between the use of automatism in the legal and clinical literature. We close by addressing several issues raised by the automatism defense: semantic ambiguity surrounding the term automatism, the presence or absence of consciousness during automatisms, and the methodological obstacles that have hindered the study of cognition during automatisms.

  13. Self-Compassion and Automatic Thoughts

    ERIC Educational Resources Information Center

    Akin, Ahmet

    2012-01-01

    The aim of this research is to examine the relationships between self-compassion and automatic thoughts. Participants were 299 university students. In this study, the Self-compassion Scale and the Automatic Thoughts Questionnaire were used. The relationships between self-compassion and automatic thoughts were examined using correlation analysis…

  14. Exploring the effects of a rigid body on the evolution of the Rayleigh Taylor instability

    NASA Astrophysics Data System (ADS)

    Brown, Christopher; Dalziel, Stuart B.

    2014-11-01

    This talk discusses the effects of a rigid solid boundary impeding the evolution of the Rayleigh-Taylor (RT) instability. Previous experimental studies e.g. those of Linden, Dalziel and Davies Wykes, amongst others, used a solid rigid barrier to separate the two layers which when removed revealed the RT unstable interface. But what happens if the barrier is only partially removed? Initially the interface grows classically, however, this is soon replaced by two circulation cells, one either side of the barrier. The circulation forces fluid from both layers onto the interface at z = 0 , resulting in a RT mixing zone superimposed onto the circulation cells. This RT mixing zone grows in a manner similar to that found by Andrews et al. for RT in water tunnels, except here the flow is modified by the end wall. Near to the end wall the two circulation cells are deflected vertically, stretching the mixing zone vertically along the end wall rapidly. Using a combination of ILES simulations and low Atwood number experiments this talk will present a model for a multi-stage mixing process, discussing the effects of the opening size on the density change of each layer, buoyancy driven flux through the opening and mixing efficiency. ©British Crown Owned Copyright 2014/AWE.

  15. Regular and chaotic motions in applied dynamics of a rigid body.

    PubMed

    Beletskii, V. V.; Pivovarov, M. L.; Starostin, E. L.

    1996-06-01

    Periodic and regular motions, having a predictable functioning mode, play an important role in many problems of dynamics. The achievements of mathematics and mechanics (beginning with Poincare) have made it possible to establish that such motion modes, generally speaking, are local and form "islands" of regularity in a "chaotic sea" of essentially unpredictable trajectories. The development of computer techniques together with theoretical investigations makes it possible to study the global structure of the phase space of many problems having applied significance. A review of a number of such problems, considered by the authors in the past four or five years, is given in this paper. These include orientation and rotation problems of artificial and natural celestial bodies and the problem of controlling the motion of a locomotion robot. The structure of phase space is investigated for these problems. The phase trajectories of the motion are constructed by a numerical implementation of the Poincare point map method. Distinctions are made between regular (or resonance), quasiregular (or conditionally periodic), and chaotic trajectories. The evolution of the phase picture as the parameters are varied is investigated. A large number of "phase portraits" gives a notion of the arrangement and size of the stability islands in the "sea" of chaotic motions, about the appearance and disappearance of these islands as the parameters are varied, etc. (c) 1996 American Institute of Physics. PMID:12780243

  16. An efficient conservative cut-cell method for rigid bodies interacting with viscous compressible flows

    NASA Astrophysics Data System (ADS)

    Schneiders, Lennart; Günther, Claudia; Meinke, Matthias; Schröder, Wolfgang

    2016-04-01

    A Cartesian cut-cell method for viscous flows interacting with freely moving boundaries is presented. The method enables a sharp resolution of the embedded boundaries and strictly conserves mass, momentum, and energy. A new explicit Runge-Kutta scheme (PC-RK) is introduced by which the overall computational time is reduced by a factor of up to 2.5. The new scheme is a predictor-corrector type reformulation of a popular class of Runge-Kutta methods which substantially reduces the computational effort for tracking the moving boundaries and subsequently reinitializing the solver impairing neither stability nor accuracy. The structural motion is computed by an implicit scheme with good stability properties due to a strong-coupling strategy and the conservative discretization of the flow solver at the material interfaces. A new formulation for the treatment of small cut cells is proposed with high accuracy and robustness for arbitrary geometries based on a weighted Taylor-series approach solved via singular-value decomposition. The efficiency and the accuracy of the new method are demonstrated for several three-dimensional cases of laminar and turbulent particulate flow. It is shown that the new method remains fully conservative even for large displacements of the boundaries leading to a fast convergence of the fluid-solid coupling while spurious force oscillations inherent to this class of methods are effectively suppressed. The results substantiate the good stability and accuracy properties of the scheme even on relatively coarse meshes.

  17. Do Lehmann cholesteric droplets subjected to a temperature gradient rotate as rigid bodies?

    PubMed

    Poy, Guilhem; Oswald, Patrick

    2016-03-01

    We performed a Fluorescence Recovery After Photobleaching (FRAP) experiment during the Lehmann rotation of cholesteric droplets in thermodynamic coexistence with the isotropic liquid and subjected to a temperature gradient. By creating and tracking bleached spots near the surface of banded droplets (in which the cholesteric helix is perpendicular to the gradient) and concentric circle droplets oriented by an electric field (in which the helix is parallel to the gradient), we found that neither type of droplet rotates as a solid. This result shows that the texture rotation is mainly due to the local director rotation.

  18. Arterial mechanical motion estimation based on a semi-rigid body deformation approach.

    PubMed

    Guzman, Pablo; Hamarneh, Ghassan; Ros, Rafael; Ros, Eduardo

    2014-01-01

    Arterial motion estimation in ultrasound (US) sequences is a hard task due to noise and discontinuities in the signal derived from US artifacts. Characterizing the mechanical properties of the artery is a promising novel imaging technique to diagnose various cardiovascular pathologies and a new way of obtaining relevant clinical information, such as determining the absence of dicrotic peak, estimating the Augmentation Index (AIx), the arterial pressure or the arterial stiffness. One of the advantages of using US imaging is the non-invasive nature of the technique unlike Intra Vascular Ultra Sound (IVUS) or angiography invasive techniques, plus the relative low cost of the US units. In this paper, we propose a semi rigid deformable method based on Soft Bodies dynamics realized by a hybrid motion approach based on cross-correlation and optical flow methods to quantify the elasticity of the artery. We evaluate and compare different techniques (for instance optical flow methods) on which our approach is based. The goal of this comparative study is to identify the best model to be used and the impact of the accuracy of these different stages in the proposed method. To this end, an exhaustive assessment has been conducted in order to decide which model is the most appropriate for registering the variation of the arterial diameter over time. Our experiments involved a total of 1620 evaluations within nine simulated sequences of 84 frames each and the estimation of four error metrics. We conclude that our proposed approach obtains approximately 2.5 times higher accuracy than conventional state-of-the-art techniques. PMID:24871987

  19. Regular and chaotic motions in applied dynamics of a rigid body.

    PubMed

    Beletskii, V. V.; Pivovarov, M. L.; Starostin, E. L.

    1996-06-01

    Periodic and regular motions, having a predictable functioning mode, play an important role in many problems of dynamics. The achievements of mathematics and mechanics (beginning with Poincare) have made it possible to establish that such motion modes, generally speaking, are local and form "islands" of regularity in a "chaotic sea" of essentially unpredictable trajectories. The development of computer techniques together with theoretical investigations makes it possible to study the global structure of the phase space of many problems having applied significance. A review of a number of such problems, considered by the authors in the past four or five years, is given in this paper. These include orientation and rotation problems of artificial and natural celestial bodies and the problem of controlling the motion of a locomotion robot. The structure of phase space is investigated for these problems. The phase trajectories of the motion are constructed by a numerical implementation of the Poincare point map method. Distinctions are made between regular (or resonance), quasiregular (or conditionally periodic), and chaotic trajectories. The evolution of the phase picture as the parameters are varied is investigated. A large number of "phase portraits" gives a notion of the arrangement and size of the stability islands in the "sea" of chaotic motions, about the appearance and disappearance of these islands as the parameters are varied, etc. (c) 1996 American Institute of Physics.

  20. A Fully Coupled Multi-Rigid-Body Fuel Slosh Dynamics Model Applied to the Triana Stack

    NASA Technical Reports Server (NTRS)

    London, K. W.

    2001-01-01

    A somewhat general multibody model is presented that accounts for energy dissipation associated with fuel slosh and which unifies some of the existing more specialized representations. This model is used to predict the mutation growth time constant for the Triana Spacecraft, or Stack, consisting of the Triana Observatory mated with the Gyroscopic Upper Stage of GUS (includes the solid rocket motor, SRM, booster). At the nominal spin rate of 60 rpm and with 145 kg of hydrazine propellant on board, a time constant of 116 s is predicted for worst case sloshing of a spherical slug model compared to 1,681 s (nominal), 1,043 s (worst case) for sloshing of a three degree of freedom pendulum model.

  1. Rigid-body rotation of an electron cloud in divergent magnetic fields

    SciTech Connect

    Fruchtman, A.; Gueroult, R.; Fisch, N. J.

    2013-07-10

    For a given voltage across a divergent poloidal magnetic field, two electric potential distributions, each supported by a rigid-rotor electron cloud rotating with a different frequency, are found analytically. The two rotation frequencies correspond to the slow and fast rotation frequencies known in uniform plasma. Due to the centrifugal force, the equipotential surfaces, that correspond to the two electric potential distributions, diverge more than the magnetic surfaces do, the equipotential surfaces in the fast mode diverge largely in particular. The departure of the equipotential surfaces from the magnetic field surfaces may have a significant focusing effect on the ions accelerated by the electric field. Furthermore, the focusing effect could be important for laboratory plasma accelerators as well as for collimation of astrophysical jets.

  2. Pseudo-Rigid-Body Model and Kinematic Analysis of MRI-Actuated Catheters

    PubMed Central

    Greigarn, Tipakorn; Çavuşoğlu, M. Cenk

    2015-01-01

    This paper presents a kinematic study of a pseudorigid-body model (PRBM) of MRI-compatible, magnetically actuated, steerable catheters. It includes a derivation of a mathematical model of the PRBM of the catheter, singularity studies of the model, and a new manipulability measure. While the forward kinematics of the model presented here is applicable to PRBMs for other applications, actuation method is unique to the particular design. Hence, a careful study of singularities and manipulability of the model is required. The singularities are studied from the underlying equations of motion with intuitive interpretations. The proposed manipulability measure is a generalization of the inverse condition number manipulability measure of robotic manipulators. While the PRBM is an approximation of the flexible catheter, kinematic studies of the PRBM still provide some insight into feasibility and limitations of the catheter, which is beneficial to the design and motion planning of the catheter. PMID:26413380

  3. Rigid-body rotation of an electron cloud in divergent magnetic fields

    DOE PAGES

    Fruchtman, A.; Gueroult, R.; Fisch, N. J.

    2013-07-10

    For a given voltage across a divergent poloidal magnetic field, two electric potential distributions, each supported by a rigid-rotor electron cloud rotating with a different frequency, are found analytically. The two rotation frequencies correspond to the slow and fast rotation frequencies known in uniform plasma. Due to the centrifugal force, the equipotential surfaces, that correspond to the two electric potential distributions, diverge more than the magnetic surfaces do, the equipotential surfaces in the fast mode diverge largely in particular. The departure of the equipotential surfaces from the magnetic field surfaces may have a significant focusing effect on the ions acceleratedmore » by the electric field. Furthermore, the focusing effect could be important for laboratory plasma accelerators as well as for collimation of astrophysical jets.« less

  4. The Advanced Part of a Treatise on the Dynamics of a System of Rigid Bodies

    NASA Astrophysics Data System (ADS)

    Routh, Edward John

    2013-03-01

    Preface; 1. Moving axes and relative motion; 2. Oscillations about equilibrium; 3. Oscillations about a state of motion; 4. Motion of a body under no forces; 5. Motion of a body under any forces; 6. Nature of the motion given by linear equations and the conditions of stability; 7. Free and forced oscillations; 8. Determination of the constants of integration in terms of the initial conditions; 9. Calculus of finite differences; 10. Calculus of variations; 11. Precession and nutation; 12. Motion of the moon about its centre; 13. Motion of a string or chain; 14. Motion of a membrane; Notes.

  5. Coupling between eddy currents and rigid body rotation: analysis, computation, and experiments

    SciTech Connect

    Hua, T.Q.; Turner, L.R.

    1985-01-01

    Computation and experiment show that the coupling between eddy currents and the angular deflections resulting from those eddy currents can reduce electromagnetic effects such as forces, torques, and power dissipation to levels far less severe than would be predicted without regard for the coupling. This paper explores the coupling effects beyond the parameter range that has been explored experimentally, using analytical means and the eddy-current computer code EDDYNET. The paper also describes upcoming FELIX experiments with cantilevered beams.

  6. Stationary points of the rigid body kinetic energy and the principal axes of inertia

    NASA Astrophysics Data System (ADS)

    Labinac, Velimir; Jusup, Marko; Legović, Tarzan

    2013-10-01

    We demonstrate how searching for the extrema of the rotational kinetic energy can be exploited to introduce the idea of the principal axes of inertia in a general and intuitive way. To that end, we propose a motivational starting point for a discussion with students, followed by a physical problem that, in its simplest form, can be handled using only basic calculus. Principal axes and moments of inertia arise seamlessly as solutions to the proposed problem. A numerical example is provided to emphasize key ideas. To encourage alternative ways of thinking, we also show how similar conclusions can be derived from the square of the angular momentum. A generalized procedure, appropriate for a classical mechanics course, is outlined in the Appendix.

  7. On relative equilibria of mutually gravitating massive point and triangular rigid body

    NASA Astrophysics Data System (ADS)

    Nikonov, Vasily I.

    2014-07-01

    Planar motions of a triangular body and a massive point under the action of mutual Newtonian attraction are studied. For the first formulation the triangle is assumed to be composed of three massive points. For the second formulation it is constructed with three homogeneous rods. Some partial solutions are observed within the analysis of the geometry of mass distribution. The investigation is motivated by the problem of motion of spacecrafts near asteroid-like celestial objects possessing irregular mass distribution. Comparison of dynamical effects for two types of mass distribution is another goal of the research. Problems appearing because of irregularities in mass distributions have been known for a long time. Certain approaches to the description of motions under attraction as well as qualitative particulars of dynamics are discussed by Demin (1963), Burov & Karapetyan (1995), Buchin & Burov & Troger (2008), Burov & Guerman & Sulikashvili (2010), Kholshevnikov & Kuznetsov (2011), Beletsky & Rodnikov (2011) and Scheeres (2012).

  8. Rotation elastogram: a novel method to visualize local rigid body rotation under quasi-static compression

    NASA Astrophysics Data System (ADS)

    Sowmiya, C.; Kothawala, Ali Arshad; Thittai, Arun K.

    2016-04-01

    During manual palpation of breast masses, the perception of its stiffness and slipperiness are the two commonly used information by the physician. In order to reliably and quantitatively obtain this information several non-invasive elastography techniques have been developed that seek to provide an image of the underlying mechanical properties, mostly stiffness-related. Very few approaches have visualized the "slip" at the lesion-background boundary that only occurs for a loosely-bonded benign lesion. It has been shown that axial-shear strain distribution provides information about underlying slip. One such feature, referred to as "fill-in" was interpreted as a surrogate of the rotation undergone by an asymmetrically-oriented-loosely bonded-benign-lesion under quasi-static compression. However, imaging and direct visualization of the rotation itself has not been addressed yet. In order to accomplish this, the quality of lateral displacement estimation needs to be improved. In this simulation study, we utilize spatial compounding approach and assess the feasibility to obtain good quality rotation elastogram. The angular axial and lateral displacement estimates were obtained at different insonification angles from a phantom containing an elliptical inclusion oriented at 45°, subjected to 1% compression from the top. A multilevel 2D-block matching algorithm was used for displacement tracking and 2D-least square compounding of angular axial and lateral displacement estimates was employed. By varying the maximum steering angle and incremental angle, the improvement in the lateral motion tracking accuracy and its effects on the quality of rotational elastogram were evaluated. Results demonstrate significantly-improved rotation elastogram using this technique.

  9. Determining rigid body transformation parameters from ill-conditioned spatial marker co-ordinates.

    PubMed

    Carman, A B; Milburn, P D

    2006-01-01

    The three-dimensional location of a body-fixed axis system is described by position and orientation parameters that can be calculated knowing local and global coordinates of three or more body-fixed markers. However, marker distribution can become ill-conditioned when marker placement is symmetrical with respect to the mean of the markers. As symmetry and ill-conditioning increases, random errors in marker locations can affect the stability of orientation parameters as a result of the mathematical approach adopted. The present study investigates the methods of Veldpaus et al. [1988; Journal of Biomechanics 21, 45], Challis [1995; Biomechanics 28, 733] and Andriacchi et al. [1998; Journal of Biomedical Engineering 120, 743] for obtaining segment orientation parameters when segment markers ranged from well-defined to highly ill-conditioned depending on the symmetry of segment markers. A novel fourth approach is also presented that enabled comparisons of the root mean square error of reconstructed marker coordinates to verify that an optimal solution was obtained. No single method produced optimal results for all axis orientation parameters when reconstructing movement trials. The best performed was the method of Veldpaus et al. [1988; Journal of Biomechanics 21, 45] based on consistent results and ease of implementation. The fourth approach presented provided a reliable method in all but the highly ill-conditioned markers, however implementation was computationally difficult. The method of Challis [1995; Biomechanics 28, 733] was only suited to well-conditioned marker sets which avoided markers lying in a single plane with symmetries in marker distribution relative to the mean. The method of Andriacchi et al. [1998; Journal of Biomedical Engineering 120, 743] produced, at best, orientation parameters that approximated the results obtained by least squares methods.

  10. Rigid body mode pointing accuracy and stability criteria for an orbiting spacecraft

    NASA Technical Reports Server (NTRS)

    Sandhu, G. S.

    1974-01-01

    The effect of gravity gradient torque disturbances (which is an order of magnitude greater than the other torque disturbances and is sinusoidal with a frequency of two cycles per orbit) on pointing accuracy can be predicted very precisely. However, since the sensor noise such as star tracker and gyro inherent noise, is random, their effect can only be predicted statistically. The most common method used is computer simulation with appropriate sensor model and adjusting spacecraft control laws for minimum pointing error, as presented by Harris (1972). The general investigation outlined theoretically relates spacecraft controls to pointing accuracy in terms of the sensor noise power spectrum. The results are presented in graphical form.

  11. Thermodynamic, diffusional, and structural anomalies in rigid-body water models.

    PubMed

    Agarwal, Manish; Alam, Mohammad Parvez; Chakravarty, Charusita

    2011-06-01

    Structural, density, entropy, and diffusivity anomalies of the TIP4P/2005 model of water are mapped out over a wide range of densities and temperatures. The locus of temperatures of maximum density (TMD) for this model is very close to the experimental TMD locus for temperatures between 250 and 275 K. Four different water models (mTIP3P, TIP4P, TIP5P, and SPC/E) are compared with the TIP4P/2005 model in terms of their anomalous behavior. For all the water models, the density regimes for anomalous behavior are bounded by a low-density limit at around 0.85-0.90 g cm(-3) and a high-density limit at about 1.10-1.15 g cm(-3). The onset temperatures of the density anomaly in the various models show a much greater variation, ranging from 202 K for mTIP3P to 289 K for TIP5P. The order maps for the various water models are qualitatively very similar with the structurally anomalous regions almost superimposable in the q(tet)-τ plane. Comparison of the phase diagrams of water models with the region of liquid-state anomalies shows that the crystalline phases are much more sensitive to the choice of water models than the liquid state anomalies; for example, SPC/E and TIP4P/2005 show qualitatively similar liquid state anomalies but very different phase diagrams. The anomalies in the liquid in all the models occur at much lower pressures than those at which the melting line changes from negative to positive slope. The results in this study demonstrate several aspects of structure-entropy-diffusivity relationships of water models that can be compared with experiment and used to develop better atomistic and coarse-grained models for water.

  12. An order n formulation for the motion simulation of general multi-rigid-body tree systems

    NASA Astrophysics Data System (ADS)

    Anderson, K. S.

    1993-02-01

    An algorithm is developed for formulating dynamical equations of motion in a highly efficient concurrent form. The algorithm allows for the determination of system state derivative values in O(n) operation overall for tree structures. When the algorithm is implemented using symbolic manipulation to develop the explicit dynamical equations of motion, and appropriate substitutions are made for the reoccurring intermediate variable (as is done with the SWIFT program), substantial reductions in operations count per integration step are realized. If the inherent concurrency of the equations is then exploited through application on a parallel processing system, previously unrealizable simulation speed is possible.

  13. Rationalizing foot and ankle measurements to conform to a rigid body model.

    PubMed

    Al-Homidan, Suliman; Fletcher, Roger

    2006-04-01

    Accurate estimation of the in vivo locations of skeletal landmarks plays an integral role in several biomechanical research techniques. Because of rounding errors caused by instruments or skin movement, the data obtained through cinematography are usually not accurate and rise to a distance matrix which, because of the data errors, may not be Euclidean. The aim of this paper is to find the best Euclidean distance matrix (EDM) that approximates the distance matrix and then, an accurate estimation of the locations of skeletal landmarks. A useful scheme for parametrizing an orthogonal matrix is also described. PMID:16880161

  14. Automatic registration between reference and on-board digital tomosynthesis images for positioning verification

    SciTech Connect

    Ren Lei; Godfrey, Devon J.; Yan, Hui; Wu, Q. Jackie; Yin, Fang-Fang

    2008-02-15

    The authors developed a hybrid multiresolution rigid-body registration technique to automatically register reference digital tomosynthesis (DTS) images with on-board DTS images to guide patient positioning in radiation therapy. This hybrid registration technique uses a faster but less accurate static method to achieve an initial registration, followed by a slower but more accurate adaptive method to fine tune the registration. A multiresolution scheme is employed in the registration to further improve the registration accuracy, robustness, and efficiency. Normalized mutual information is selected as the criterion for the similarity measure and the downhill simplex method is used as the search engine. This technique was tested using image data both from an anthropomorphic chest phantom and from eight head-and-neck cancer patients. The effects of the scan angle and the region-of-interest (ROI) size on the registration accuracy and robustness were investigated. The necessity of using the adaptive registration method in the hybrid technique was validated by comparing the results of the static method and the hybrid method. With a 44 deg. scan angle and a large ROI covering the entire DTS volume, the average of the registration capture ranges in single-axis simulations was between -31 and +34 deg. for rotations and between -89 and +78 mm for translations in the phantom study, and between -38 and +38 deg. for rotations and between -58 and +65 mm for translations in the patient study. Decreasing the DTS scan angle from 44 deg. to 22 deg. mainly degraded the registration accuracy and robustness for the out-of-plane rotations. Decreasing the ROI size from the entire DTS volume to the volume surrounding the spinal cord reduced the capture ranges to between -23 and +18 deg. for rotations and between -33 and +43 mm for translations in the phantom study, and between -18 and +25 deg. for rotations and between -35 and +39 mm for translations in the patient study. Results also

  15. Automatic Target Recognizer Database Requirements

    NASA Astrophysics Data System (ADS)

    Power, David R.

    1987-09-01

    Data representative of imaging sensors and scenarios which form the inputs for automatic target recognizers (ATRs) is critical to their development, testing and performance evaluation. The Data Base Committee of the Automatic Target Recognizer Working Group provides a forum and produces products to assist collection, distribution and use of data for development of military ATR systems. Examples discussed in the paper include digital image data exchange format specifications. Requirements for ground and image truth data have been the subject of surveys. Such inputs are intended as recommendations for consideration by imagery data collection activities whose products are potentially useful for ATR development. Other topics concerning collection, reduction, use and exchange of imaging sensor data are outlined but not discussed in detail.

  16. Automatically-Programed Machine Tools

    NASA Technical Reports Server (NTRS)

    Purves, L.; Clerman, N.

    1985-01-01

    Software produces cutter location files for numerically-controlled machine tools. APT, acronym for Automatically Programed Tools, is among most widely used software systems for computerized machine tools. APT developed for explicit purpose of providing effective software system for programing NC machine tools. APT system includes specification of APT programing language and language processor, which executes APT statements and generates NC machine-tool motions specified by APT statements.

  17. Automatic computation of transfer functions

    SciTech Connect

    Atcitty, Stanley; Watson, Luke Dale

    2015-04-14

    Technologies pertaining to the automatic computation of transfer functions for a physical system are described herein. The physical system is one of an electrical system, a mechanical system, an electromechanical system, an electrochemical system, or an electromagnetic system. A netlist in the form of a matrix comprises data that is indicative of elements in the physical system, values for the elements in the physical system, and structure of the physical system. Transfer functions for the physical system are computed based upon the netlist.

  18. Toward automatic finite element analysis

    NASA Technical Reports Server (NTRS)

    Kela, Ajay; Perucchio, Renato; Voelcker, Herbert

    1987-01-01

    Two problems must be solved if the finite element method is to become a reliable and affordable blackbox engineering tool. Finite element meshes must be generated automatically from computer aided design databases and mesh analysis must be made self-adaptive. The experimental system described solves both problems in 2-D through spatial and analytical substructuring techniques that are now being extended into 3-D.

  19. Automatic translation among spoken languages

    NASA Astrophysics Data System (ADS)

    Walter, Sharon M.; Costigan, Kelly

    1994-02-01

    The Machine Aided Voice Translation (MAVT) system was developed in response to the shortage of experienced military field interrogators with both foreign language proficiency and interrogation skills. Combining speech recognition, machine translation, and speech generation technologies, the MAVT accepts an interrogator's spoken English question and translates it into spoken Spanish. The spoken Spanish response of the potential informant can then be translated into spoken English. Potential military and civilian applications for automatic spoken language translation technology are discussed in this paper.

  20. Automatic translation among spoken languages

    NASA Technical Reports Server (NTRS)

    Walter, Sharon M.; Costigan, Kelly

    1994-01-01

    The Machine Aided Voice Translation (MAVT) system was developed in response to the shortage of experienced military field interrogators with both foreign language proficiency and interrogation skills. Combining speech recognition, machine translation, and speech generation technologies, the MAVT accepts an interrogator's spoken English question and translates it into spoken Spanish. The spoken Spanish response of the potential informant can then be translated into spoken English. Potential military and civilian applications for automatic spoken language translation technology are discussed in this paper.

  1. Group Dynamics in Automatic Imitation

    PubMed Central

    Wilson, Neil; Reddy, Geetha; Catmur, Caroline

    2016-01-01

    Imitation–matching the configural body movements of another individual–plays a crucial part in social interaction. We investigated whether automatic imitation is not only influenced by who we imitate (ingroup vs. outgroup member) but also by the nature of an expected interaction situation (competitive vs. cooperative). In line with assumptions from Social Identity Theory), we predicted that both social group membership and the expected situation impact on the level of automatic imitation. We adopted a 2 (group membership target: ingroup, outgroup) x 2 (situation: cooperative, competitive) design. The dependent variable was the degree to which participants imitated the target in a reaction time automatic imitation task. 99 female students from two British Universities participated. We found a significant two-way interaction on the imitation effect. When interacting in expectation of cooperation, imitation was stronger for an ingroup target compared to an outgroup target. However, this was not the case in the competitive condition where imitation did not differ between ingroup and outgroup target. This demonstrates that the goal structure of an expected interaction will determine the extent to which intergroup relations influence imitation, supporting a social identity approach. PMID:27657926

  2. Automatic Contrail Detection and Segmentation

    NASA Technical Reports Server (NTRS)

    Weiss, John M.; Christopher, Sundar A.; Welch, Ronald M.

    1998-01-01

    Automatic contrail detection is of major importance in the study of the atmospheric effects of aviation. Due to the large volume of satellite imagery, selecting contrail images for study by hand is impractical and highly subject to human error. It is far better to have a system in place that will automatically evaluate an image to determine 1) whether it contains contrails and 2) where the contrails are located. Preliminary studies indicate that it is possible to automatically detect and locate contrails in Advanced Very High Resolution Radiometer (AVHRR) imagery with a high degree of confidence. Once contrails have been identified and localized in a satellite image, it is useful to segment the image into contrail versus noncontrail pixels. The ability to partition image pixels makes it possible to determine the optical properties of contrails, including optical thickness and particle size. In this paper, we describe a new technique for segmenting satellite images containing contrails. This method has good potential for creating a contrail climatology in an automated fashion. The majority of contrails are detected, rejecting clutter in the image, even cirrus streaks. Long, thin contrails are most easily detected. However, some contrails may be missed because they are curved, diffused over a large area, or present in short segments. Contrails average 2-3 km in width for the cases studied.

  3. Automatic programming for critical applications

    NASA Technical Reports Server (NTRS)

    Loganantharaj, Raj L.

    1988-01-01

    The important phases of a software life cycle include verification and maintenance. Usually, the execution performance is an expected requirement in a software development process. Unfortunately, the verification and the maintenance of programs are the time consuming and the frustrating aspects of software engineering. The verification cannot be waived for the programs used for critical applications such as, military, space, and nuclear plants. As a consequence, synthesis of programs from specifications, an alternative way of developing correct programs, is becoming popular. The definition, or what is understood by automatic programming, has been changed with our expectations. At present, the goal of automatic programming is the automation of programming process. Specifically, it means the application of artificial intelligence to software engineering in order to define techniques and create environments that help in the creation of high level programs. The automatic programming process may be divided into two phases: the problem acquisition phase and the program synthesis phase. In the problem acquisition phase, an informal specification of the problem is transformed into an unambiguous specification while in the program synthesis phase such a specification is further transformed into a concrete, executable program.

  4. The Automaticity of Social Life.

    PubMed

    Bargh, John A; Williams, Erin L

    2006-02-01

    Much of social life is experienced through mental processes that are not intended and about which one is fairly oblivious. These processes are automatically triggered by features of the immediate social environment, such as the group memberships of other people, the qualities of their behavior, and features of social situations (e.g., norms, one's relative power). Recent research has shown these nonconscious influences to extend beyond the perception and interpretation of the social world to the actual guidance, over extended time periods, of one's important goal pursuits and social interactions.

  5. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  6. The Automaticity of Social Life.

    PubMed

    Bargh, John A; Williams, Erin L

    2006-02-01

    Much of social life is experienced through mental processes that are not intended and about which one is fairly oblivious. These processes are automatically triggered by features of the immediate social environment, such as the group memberships of other people, the qualities of their behavior, and features of social situations (e.g., norms, one's relative power). Recent research has shown these nonconscious influences to extend beyond the perception and interpretation of the social world to the actual guidance, over extended time periods, of one's important goal pursuits and social interactions. PMID:18568084

  7. Automatic Computer Mapping of Terrain

    NASA Technical Reports Server (NTRS)

    Smedes, H. W.

    1971-01-01

    Computer processing of 17 wavelength bands of visible, reflective infrared, and thermal infrared scanner spectrometer data, and of three wavelength bands derived from color aerial film has resulted in successful automatic computer mapping of eight or more terrain classes in a Yellowstone National Park test site. The tests involved: (1) supervised and non-supervised computer programs; (2) special preprocessing of the scanner data to reduce computer processing time and cost, and improve the accuracy; and (3) studies of the effectiveness of the proposed Earth Resources Technology Satellite (ERTS) data channels in the automatic mapping of the same terrain, based on simulations, using the same set of scanner data. The following terrain classes have been mapped with greater than 80 percent accuracy in a 12-square-mile area with 1,800 feet of relief; (1) bedrock exposures, (2) vegetated rock rubble, (3) talus, (4) glacial kame meadow, (5) glacial till meadow, (6) forest, (7) bog, and (8) water. In addition, shadows of clouds and cliffs are depicted, but were greatly reduced by using preprocessing techniques.

  8. Capillary-driven automatic packaging.

    PubMed

    Ding, Yuzhe; Hong, Lingfei; Nie, Baoqing; Lam, Kit S; Pan, Tingrui

    2011-04-21

    Packaging continues to be one of the most challenging steps in micro-nanofabrication, as many emerging techniques (e.g., soft lithography) are incompatible with the standard high-precision alignment and bonding equipment. In this paper, we present a simple-to-operate, easy-to-adapt packaging strategy, referred to as Capillary-driven Automatic Packaging (CAP), to achieve automatic packaging process, including the desired features of spontaneous alignment and bonding, wide applicability to various materials, potential scalability, and direct incorporation in the layout. Specifically, self-alignment and self-engagement of the CAP process induced by the interfacial capillary interactions between a liquid capillary bridge and the top and bottom substrates have been experimentally characterized and theoretically analyzed with scalable implications. High-precision alignment (of less than 10 µm) and outstanding bonding performance (up to 300 kPa) has been reliably obtained. In addition, a 3D microfluidic network, aligned and bonded by the CAP technique, has been devised to demonstrate the applicability of this facile yet robust packaging technique for emerging microfluidic and bioengineering applications.

  9. Automatic temperature controlled retinal photocoagulation

    NASA Astrophysics Data System (ADS)

    Schlott, Kerstin; Koinzer, Stefan; Ptaszynski, Lars; Bever, Marco; Baade, Alex; Roider, Johann; Birngruber, Reginald; Brinkmann, Ralf

    2012-06-01

    Laser coagulation is a treatment method for many retinal diseases. Due to variations in fundus pigmentation and light scattering inside the eye globe, different lesion strengths are often achieved. The aim of this work is to realize an automatic feedback algorithm to generate desired lesion strengths by controlling the retinal temperature increase with the irradiation time. Optoacoustics afford non-invasive retinal temperature monitoring during laser treatment. A 75 ns/523 nm Q-switched Nd:YLF laser was used to excite the temperature-dependent pressure amplitudes, which were detected at the cornea by an ultrasonic transducer embedded in a contact lens. A 532 nm continuous wave Nd:YAG laser served for photocoagulation. The ED50 temperatures, for which the probability of ophthalmoscopically visible lesions after one hour in vivo in rabbits was 50%, varied from 63°C for 20 ms to 49°C for 400 ms. Arrhenius parameters were extracted as ΔE=273 J mol-1 and A=3.1044 s-1. Control algorithms for mild and strong lesions were developed, which led to average lesion diameters of 162+/-34 μm and 189+/-34 μm, respectively. It could be demonstrated that the sizes of the automatically controlled lesions were widely independent of the treatment laser power and the retinal pigmentation.

  10. Automatic Inspection In Industry Today

    NASA Astrophysics Data System (ADS)

    Brook, Richard A.

    1989-02-01

    With increasing competition in the manufacturing industries product quality is becoming even more important. The shortcomings of human inspectors in many applications are well know, however, the eye/brain combination is very powerful and difficult to replace. At best, any system only simulates a small subset of the human's operations. The economic justification for installing automatic inspection is often difficult without previous applications experience. It therefore calls for confidence and long-term vision by those making the decisions. Over the last ten years the use of such systems has increased as the technology involved has matured and the risks have diminished. There is now a complete spectrum of industrial applications from simple, low-cost systems using standard sensors and computer hardware to the higher cost, custom-designed systems using novel sensors and processing hardware. The underlying growth in enabling technology has been in many areas; sensors and sensing techniques, signal processing and data processing have all moved forward rapidly. This paper will examine the currrent state of automatic inspection and look to the future. The use of expert systems is an obvious candidate. Parallel processing, giving massive increases in the speed of data reduction, is also likely to play a major role in future systems.

  11. Automatic Inspection In Industry Today

    NASA Astrophysics Data System (ADS)

    Brook, Richard A.

    1989-03-01

    With increasing competition in the manufacturing industries product quality is becoming even more important. The shortcomings of human inspectors in many applications are well know, however, the eye/brain combination is very powerful and difficult to replace. At best, any system only simulates a small subset of the human's operations. The economic justification for installing automatic inspection is often difficult without previous applications experience. It therefore calls for confidence and long-term vision by those making the decisions. Over the last ten years the use of such systems has increased as the technology involved has matured and the risks have diminished. There is now a complete spectrum of industrial applications from simple, low-cost systems using standard sensors and computer hardware to the higher cost, custom-designed systems using novel sensors and processing hardware. The underlying growth in enabling technology has been in many areas; sensors and sensing techniques, signal processing and data processing have all moved forward rapidly. This paper will examine the currrent state of automatic inspection and look to the future. The use of expert systems is an obvious candidate. Parallel processing, giving massive increases in the speed of data reduction, is also likely to play a major role in future systems.

  12. ANPS - AUTOMATIC NETWORK PROGRAMMING SYSTEM

    NASA Technical Reports Server (NTRS)

    Schroer, B. J.

    1994-01-01

    Development of some of the space program's large simulation projects -- like the project which involves simulating the countdown sequence prior to spacecraft liftoff -- requires the support of automated tools and techniques. The number of preconditions which must be met for a successful spacecraft launch and the complexity of their interrelationship account for the difficulty of creating an accurate model of the countdown sequence. Researchers developed ANPS for the Nasa Marshall Space Flight Center to assist programmers attempting to model the pre-launch countdown sequence. Incorporating the elements of automatic programming as its foundation, ANPS aids the user in defining the problem and then automatically writes the appropriate simulation program in GPSS/PC code. The program's interactive user dialogue interface creates an internal problem specification file from user responses which includes the time line for the countdown sequence, the attributes for the individual activities which are part of a launch, and the dependent relationships between the activities. The program's automatic simulation code generator receives the file as input and selects appropriate macros from the library of software modules to generate the simulation code in the target language GPSS/PC. The user can recall the problem specification file for modification to effect any desired changes in the source code. ANPS is designed to write simulations for problems concerning the pre-launch activities of space vehicles and the operation of ground support equipment and has potential for use in developing network reliability models for hardware systems and subsystems. ANPS was developed in 1988 for use on IBM PC or compatible machines. The program requires at least 640 KB memory and one 360 KB disk drive, PC DOS Version 2.0 or above, and GPSS/PC System Version 2.0 from Minuteman Software. The program is written in Turbo Prolog Version 2.0. GPSS/PC is a trademark of Minuteman Software. Turbo Prolog

  13. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1981-01-01

    A commutated automatic gain control system (AGC) was designed and constructed for the prototype Loran C receiver. The AGC is designed to improve the signal-to-signal ratio of the received Loran signals. The AGC design does not require any analog to digital conversion and it utilizes commonly available components. The AGC consists of: (1) a circuit which samples the peak of the envelope of the Loran signal to obtain an AGC voltage for each of three Loran stations, (2) a dc gain circuit to control the overall gain of the AGC system, and (3) an AGC amplification of the input RF signal. The performance of the AGC system was observed in bench and flight tests; it has improved the overall accuracy of the receiver. Improvements in the accuracy of the time difference calculations to within approx. + or - 1.5 microseconds of the observed time differnces for a given position are reported.

  14. Automatic inspection of leather surfaces

    NASA Astrophysics Data System (ADS)

    Poelzleitner, Wolfgang; Niel, Albert

    1994-10-01

    This paper describes the key elements of a system for detecting quality defects on leather surfaces. The inspection task must treat defects like scars, mite nests, warts, open fissures, healed scars, holes, pin holes, and fat folds. The industrial detection of these defects is difficult because of the large dimensions of the leather hides (2 m X 3 m), and the small dimensions of the defects (150 micrometers X 150 micrometers ). Pattern recognition approaches suffer from the fact that defects are hidden on an irregularly textured background, and can be hardly seen visually by human graders. We describe the methods tested for automatic classification using image processing, which include preprocessing, local feature description of texture elements, and final segmentation and grading of defects. We conclude with a statistical evaluation of the recognition error rate, and an outlook on the expected industrial performance.

  15. Automatic blocking of nested loops

    NASA Technical Reports Server (NTRS)

    Schreiber, Robert; Dongarra, Jack J.

    1990-01-01

    Blocked algorithms have much better properties of data locality and therefore can be much more efficient than ordinary algorithms when a memory hierarchy is involved. On the other hand, they are very difficult to write and to tune for particular machines. The reorganization is considered of nested loops through the use of known program transformations in order to create blocked algorithms automatically. The program transformations used are strip mining, loop interchange, and a variant of loop skewing in which invertible linear transformations (with integer coordinates) of the loop indices are allowed. Some problems are solved concerning the optimal application of these transformations. It is shown, in a very general setting, how to choose a nearly optimal set of transformed indices. It is then shown, in one particular but rather frequently occurring situation, how to choose an optimal set of block sizes.

  16. Automatic tools for system testing

    NASA Technical Reports Server (NTRS)

    Peccia, N. M.

    1993-01-01

    As spacecraft control and other space-related ground systems become increasingly complex, the effort required in testing and validation also increases. Implementation of a spacecraft control system normally involves a number of incremental deliveries. In addition kernel or general purpose software may also be involved, which must itself be considered in the integration and testing program. Tools can be used to assist this testing. These can reduce the effort required or alternatively they can ensure that for a given level of effort, a better job is done. Great benefit could be derived by automating certain types of testing (interactive software) which up to now has been performed manually at a terminal. This paper reports on an on-going study. The study examines means of automating spacecraft control system testing, evaluates relevant commercial tools and aims to prototype basic automatic testing functions.

  17. Automatic home medical product recommendation.

    PubMed

    Luo, Gang; Thomas, Selena B; Tang, Chunqiang

    2012-04-01

    Web-based personal health records (PHRs) are being widely deployed. To improve PHR's capability and usability, we proposed the concept of intelligent PHR (iPHR). In this paper, we use automatic home medical product recommendation as a concrete application to demonstrate the benefits of introducing intelligence into PHRs. In this new application domain, we develop several techniques to address the emerging challenges. Our approach uses treatment knowledge and nursing knowledge, and extends the language modeling method to (1) construct a topic-selection input interface for recommending home medical products, (2) produce a global ranking of Web pages retrieved by multiple queries, and (3) provide diverse search results. We demonstrate the effectiveness of our techniques using USMLE medical exam cases. PMID:20703712

  18. Automatic Mechetronic Wheel Light Device

    DOEpatents

    Khan, Mohammed John Fitzgerald

    2004-09-14

    A wheel lighting device for illuminating a wheel of a vehicle to increase safety and enhance aesthetics. The device produces the appearance of a "ring of light" on a vehicle's wheels as the vehicle moves. The "ring of light" can automatically change in color and/or brightness according to a vehicle's speed, acceleration, jerk, selection of transmission gears, and/or engine speed. The device provides auxiliary indicator lights by producing light in conjunction with a vehicle's turn signals, hazard lights, alarm systems, and etc. The device comprises a combination of mechanical and electronic components and can be placed on the outer or inner surface of a wheel or made integral to a wheel or wheel cover. The device can be configured for all vehicle types, and is electrically powered by a vehicle's electrical system and/or battery.

  19. Automatic insulation resistance testing apparatus

    DOEpatents

    Wyant, Francis J.; Nowlen, Steven P.; Luker, Spencer M.

    2005-06-14

    An apparatus and method for automatic measurement of insulation resistances of a multi-conductor cable. In one embodiment of the invention, the apparatus comprises a power supply source, an input measuring means, an output measuring means, a plurality of input relay controlled contacts, a plurality of output relay controlled contacts, a relay controller and a computer. In another embodiment of the invention the apparatus comprises a power supply source, an input measuring means, an output measuring means, an input switching unit, an output switching unit and a control unit/data logger. Embodiments of the apparatus of the invention may also incorporate cable fire testing means. The apparatus and methods of the present invention use either voltage or current for input and output measured variables.

  20. Autoclass: An automatic classification system

    NASA Technical Reports Server (NTRS)

    Stutz, John; Cheeseman, Peter; Hanson, Robin

    1991-01-01

    The task of inferring a set of classes and class descriptions most likely to explain a given data set can be placed on a firm theoretical foundation using Bayesian statistics. Within this framework, and using various mathematical and algorithmic approximations, the AutoClass System searches for the most probable classifications, automatically choosing the number of classes and complexity of class descriptions. A simpler version of AutoClass has been applied to many large real data sets, has discovered new independently-verified phenomena, and has been released as a robust software package. Recent extensions allow attributes to be selectively correlated within particular classes, and allow classes to inherit, or share, model parameters through a class hierarchy. The mathematical foundations of AutoClass are summarized.

  1. Automatic electronic fish tracking system

    NASA Technical Reports Server (NTRS)

    Osborne, P. W.; Hoffman, E.; Merriner, J. V.; Richards, C. E.; Lovelady, R. W.

    1976-01-01

    A newly developed electronic fish tracking system to automatically monitor the movements and migratory habits of fish is reported. The system is aimed particularly at studies of effects on fish life of industrial facilities which use rivers or lakes to dump their effluents. Location of fish is acquired by means of acoustic links from the fish to underwater Listening Stations, and by radio links which relay tracking information to a shore-based Data Base. Fish over 4 inches long may be tracked over a 5 x 5 mile area. The electronic fish tracking system provides the marine scientist with electronics which permit studies that were not practical in the past and which are cost-effective compared to manual methods.

  2. Automatic Synthesis Of Greedy Programs

    NASA Astrophysics Data System (ADS)

    Bhansali, Sanjay; Miriyala, Kanth; Harandi, Mehdi T.

    1989-03-01

    This paper describes a knowledge based approach to automatically generate Lisp programs using the Greedy method of algorithm design. The system's knowledge base is composed of heuristics for recognizing problems amenable to the Greedy method and knowledge about the Greedy strategy itself (i.e., rules for local optimization, constraint satisfaction, candidate ordering and candidate selection). The system has been able to generate programs for a wide variety of problems including the job-scheduling problem, the 0-1 knapsack problem, the minimal spanning tree problem, and the problem of arranging files on tape to minimize access time. For the special class of problems called matroids, the synthesized program provides optimal solutions, whereas for most other problems the solutions are near-optimal.

  3. Automatic toilet seat lowering apparatus

    SciTech Connect

    Guerty, Harold G.

    1994-09-06

    A toilet seat lowering apparatus includes a housing defining an internal cavity for receiving water from the water supply line to the toilet holding tank. A descent delay assembly of the apparatus can include a stationary dam member and a rotating dam member for dividing the internal cavity into an inlet chamber and an outlet chamber and controlling the intake and evacuation of water in a delayed fashion. A descent initiator is activated when the internal cavity is filled with pressurized water and automatically begins the lowering of the toilet seat from its upright position, which lowering is also controlled by the descent delay assembly. In an alternative embodiment, the descent initiator and the descent delay assembly can be combined in a piston linked to the rotating dam member and provided with a water channel for creating a resisting pressure to the advancing piston and thereby slowing the associated descent of the toilet seat. A toilet seat lowering apparatus includes a housing defining an internal cavity for receiving water from the water supply line to the toilet holding tank. A descent delay assembly of the apparatus can include a stationary dam member and a rotating dam member for dividing the internal cavity into an inlet chamber and an outlet chamber and controlling the intake and evacuation of water in a delayed fashion. A descent initiator is activated when the internal cavity is filled with pressurized water and automatically begins the lowering of the toilet seat from its upright position, which lowering is also controlled by the descent delay assembly. In an alternative embodiment, the descent initiator and the descent delay assembly can be combined in a piston linked to the rotating dam member and provided with a water channel for creating a resisting pressure to the advancing piston and thereby slowing the associated descent of the toilet seat.

  4. Automatic star-horizon angle measurement system

    NASA Technical Reports Server (NTRS)

    Koerber, K.; Koso, D. A.; Nardella, P. C.

    1969-01-01

    Automatic star horizontal angle measuring aid for general navigational use incorporates an Apollo type sextant. The eyepiece of the sextant is replaced with two light detectors and appropriate circuitry. The device automatically determines the angle between a navigational star and a unique point on the earths horizon as seen on a spacecraft.

  5. Automatic Item Generation of Probability Word Problems

    ERIC Educational Resources Information Center

    Holling, Heinz; Bertling, Jonas P.; Zeuch, Nina

    2009-01-01

    Mathematical word problems represent a common item format for assessing student competencies. Automatic item generation (AIG) is an effective way of constructing many items with predictable difficulties, based on a set of predefined task parameters. The current study presents a framework for the automatic generation of probability word problems…

  6. Annual Report: Automatic Informative Abstracting and Extracting.

    ERIC Educational Resources Information Center

    Earl, L. L.; And Others

    The development of automatic indexing, abstracting, and extracting systems is investigated. Part I describes the development of tools for making syntactic and semantic distinctions of potential use in automatic indexing and extracting. One of these tools is a program for syntactic analysis (i.e., parsing) of English, the other is a dictionary of…

  7. Automatic Contour Tracking in Ultrasound Images

    ERIC Educational Resources Information Center

    Li, Min; Kambhamettu, Chandra; Stone, Maureen

    2005-01-01

    In this paper, a new automatic contour tracking system, EdgeTrak, for the ultrasound image sequences of human tongue is presented. The images are produced by a head and transducer support system (HATS). The noise and unrelated high-contrast edges in ultrasound images make it very difficult to automatically detect the correct tongue surfaces. In…

  8. Automatic Grading of Spreadsheet and Database Skills

    ERIC Educational Resources Information Center

    Kovacic, Zlatko J.; Green, John Steven

    2012-01-01

    Growing enrollment in distance education has increased student-to-lecturer ratios and, therefore, increased the workload of the lecturer. This growing enrollment has resulted in mounting efforts to develop automatic grading systems in an effort to reduce this workload. While research in the design and development of automatic grading systems has a…

  9. Automatic data editing: a brief introduction

    SciTech Connect

    Liepins, G.E.

    1982-01-01

    This paper briefly discusses the automatic data editing process: (1) check the data records for consistency, (2) analyze the inconsistent records to determine the inconsistent variables. It is stated that the application of automatic data editing is broad, and two specific examples are cited. One example, that of a vehicle maintenance data base is used to illustrate the process.

  10. 6 CFR 7.28 - Automatic declassification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Automatic declassification. 7.28 Section 7.28 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY CLASSIFIED NATIONAL SECURITY INFORMATION Classified Information § 7.28 Automatic declassification. (a) Subject to paragraph (b) of...

  11. Automatic Weather Station (AWS) Lidar

    NASA Technical Reports Server (NTRS)

    Rall, Jonathan A.R.; Abshire, James B.; Spinhirne, James D.; Smith, David E. (Technical Monitor)

    2000-01-01

    An autonomous, low-power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. This compact, portable lidar will operate continuously in a temperature controlled enclosure, charge its own batteries through a combination of a small rugged wind generator and solar panels, and transmit its data from remote locations to ground stations via satellite. A network of these instruments will be established by co-locating them at remote Automatic Weather Station (AWS) sites in Antarctica under the auspices of the National Science Foundation (NSF). The NSF Office of Polar Programs provides support to place the weather stations in remote areas of Antarctica in support of meteorological research and operations. The AWS meteorological data will directly benefit the analysis of the lidar data while a network of ground based atmospheric lidar will provide knowledge regarding the temporal evolution and spatial extent of Type la polar stratospheric clouds (PSC). These clouds play a crucial role in the annual austral springtime destruction of stratospheric ozone over Antarctica, i.e. the ozone hole. In addition, the lidar will monitor and record the general atmospheric conditions (transmission and backscatter) of the overlying atmosphere which will benefit the Geoscience Laser Altimeter System (GLAS). Prototype lidar instruments have been deployed to the Amundsen-Scott South Pole Station (1995-96, 2000) and to an Automated Geophysical Observatory site (AGO 1) in January 1999. We report on data acquired with these instruments, instrument performance, and anticipated performance of the AWS Lidar.

  12. Ekofisk automatic GPS subsidence measurements

    SciTech Connect

    Mes, M.J.; Landau, H.; Luttenberger, C.

    1996-10-01

    A fully automatic GPS satellite-based procedure for the reliable measurement of subsidence of several platforms in almost real time is described. Measurements are made continuously on platforms in the North Sea Ekofisk Field area. The procedure also yields rate measurements, which are also essential for confirming platform safety, planning of remedial work, and verification of subsidence models. GPS measurements are more attractive than seabed pressure-gauge-based platform subsidence measurements-they are much cheaper to install and maintain and not subject to gauge drift. GPS measurements were coupled to oceanographic quantities such as the platform deck clearance, which leads to less complex offshore survey procedures. Ekofisk is an oil and gas field in the southern portion of the Norwegian North Sea. Late in 1984, it was noticed that the Ekofisk platform decks were closer to the sea surface than when the platforms were installed-subsidence was the only logical explanation. After the subsidence phenomenon was recognized, an accurate measurement method was needed to measure progression of subsidence and the associated subsidence rate. One available system for which no further development was needed, was the NAVSTAR GPS-measurements started in March 1985.

  13. Automatic segmentation of psoriasis lesions

    NASA Astrophysics Data System (ADS)

    Ning, Yang; Shi, Chenbo; Wang, Li; Shu, Chang

    2014-10-01

    The automatic segmentation of psoriatic lesions is widely researched these years. It is an important step in Computer-aid methods of calculating PASI for estimation of lesions. Currently those algorithms can only handle single erythema or only deal with scaling segmentation. In practice, scaling and erythema are often mixed together. In order to get the segmentation of lesions area - this paper proposes an algorithm based on Random forests with color and texture features. The algorithm has three steps. The first step, the polarized light is applied based on the skin's Tyndall-effect in the imaging to eliminate the reflection and Lab color space are used for fitting the human perception. The second step, sliding window and its sub windows are used to get textural feature and color feature. In this step, a feature of image roughness has been defined, so that scaling can be easily separated from normal skin. In the end, Random forests will be used to ensure the generalization ability of the algorithm. This algorithm can give reliable segmentation results even the image has different lighting conditions, skin types. In the data set offered by Union Hospital, more than 90% images can be segmented accurately.

  14. Actuator for automatic cruising system

    SciTech Connect

    Suzuki, K.

    1989-03-07

    An actuator for an automatic cruising system is described, comprising: a casing; a control shaft provided in the casing for rotational movement; a control motor for driving the control shaft; an input shaft; an electromagnetic clutch and a reduction gear which are provided between the control motor and the control shaft; and an external linkage mechanism operatively connected to the control shaft; wherein the reduction gear is a type of Ferguson's mechanical paradox gear having a pinion mounted on the input shaft always connected to the control motor; a planetary gear meshing with the pinion so as to revolve around the pinion; a static internal gear meshing with the planetary gear and connected with the electromagnetic clutch for movement to a position restricting rotation of the static internal gear; and a rotary internal gear fixed on the control shaft and meshed with the planetary gear, the rotary internal gear having a number of teeth slightly different from a number of teeth of the static internal gear; and the electromagnetic clutch has a tubular electromagnetic coil coaxially provided around the input shaft and an engaging means for engaging and disengaging with the static internal gear in accordance with on-off operation of the electromagnetic coil.

  15. Automatic locking orthotic knee device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  16. Automatic restart of complex irrigation systems

    SciTech Connect

    Werner, H.D.; Alcock, R.; DeBoer, D.W.; Olson, D.I. . Dept. of Agricultural Engineering)

    1992-05-01

    Automatic restart of irrigation systems under load management has the potential to maximize pumping time during off-peak hours. Existing automation technology ranges from time delay relays to more sophisticated control using computers together with weather data to optimize irrigation practices. Centrifugal pumps and water hammer concerns prevent automatic restart of common but often complex irrigation systems in South Dakota. The irrigator must manually prime the pump and control water hammer during pipeline pressurization. Methods to prime centrifugal pumps and control water hammer facilitate automatic restart after load management is released. Seven priming methods and three water hammer control methods were investigated. A sump pump and small vacuum pump were used to test two automatic prime and restart systems in the laboratory. A variable frequency phase converter was also used to automatically control water hammer during pipeline pressurization. Economical methods to safely prime and restart centrifugal pumps were discussed. The water hammer control methods safely pressurize the pipeline but require a higher initial investment. The automatic restart systems can be used to safely restart centrifugal pumps and control water hammer after load management is released. Based upon laboratory research and a technical review of available restart components, a computer software program was developed. The program assists customers in evaluating various restart options for automatic restarting of electric irrigation pumps. For further information on the software program, contact the South Dakota State University, Department of Agricultural Engineering.

  17. Automatisms in non common law countries.

    PubMed

    Falk-Pedersen, J K

    1997-01-01

    The distinction made in the common law tradition between sane and insane automatisms, and in particular the labelling of epileptic automatisms as insane, are legal concepts which surprise and even astonish lawyers of other traditions, whether they work within a civil law system or one with elements both from civil law and common law. It could be useful to those lawyers, doctors and patients struggling for a change in the common law countries to receive comparative material from other countries. Thus, the way automatisms are dealt with in non-common law countries will be discussed with an emphasis on the Norwegian criminal law system. In Norway no distinction is made between sane and insane automatisms and the plea Not Guilty by virtue of epileptic automatism is both available and valid assuming certain conditions are met. No. 44 of the Penal Code states that acts committed while the perpetrator is unconscious are not punishable. Automatisms are regarded as "relative unconsciousness", and thus included under No. 44. Exceptions may be made if the automatism is a result of self-inflicted intoxication following the consumption of alcohol or (illegal) drugs. Also, the role and relevance of experts as well as the law of some other European countries will be briefly discussed.

  18. Automatic Operation For A Robot Lawn Mower

    NASA Astrophysics Data System (ADS)

    Huang, Y. Y.; Cao, Z. L.; Oh, S. J.; Kattan, E. U.; Hall, E. L.

    1987-02-01

    A domestic mobile robot, lawn mower, which performs the automatic operation mode, has been built up in the Center of Robotics Research, University of Cincinnati. The robot lawn mower automatically completes its work with the region filling operation, a new kind of path planning for mobile robots. Some strategies for region filling of path planning have been developed for a partly-known or a unknown environment. Also, an advanced omnidirectional navigation system and a multisensor-based control system are used in the automatic operation. Research on the robot lawn mower, especially on the region filling of path planning, is significant in industrial and agricultural applications.

  19. Automatic Behavior Pattern Classification for Social Robots

    NASA Astrophysics Data System (ADS)

    Prieto, Abraham; Bellas, Francisco; Caamaño, Pilar; Duro, Richard J.

    In this paper, we focus our attention on providing robots with a system that allows them to automatically detect behavior patterns in other robots, as a first step to introducing social responsive robots. The system is called ANPAC (Automatic Neural-based Pattern Classification). Its main feature is that ANPAC automatically adjusts the optimal processing window size and obtains the appropriate features through a dimensional transformation process that allow for the classification of behavioral patterns of large groups of entities from perception datasets. Here we present the basic elements and operation of ANPAC, and illustrate its applicability through the detection of behavior patterns in the motion of flocks.

  20. Automatic defensive control of asynchronous sequential machines

    NASA Astrophysics Data System (ADS)

    Hammer, Jacob

    2016-01-01

    Control theoretic techniques are utilised to develop automatic controllers that counteract robotic adversarial interventions in the operation of asynchronous sequential machines. The scenario centres on automatic protection against pre-programmed adversarial agents that attempt to subvert the operation of an asynchronous computing system. Necessary and sufficient conditions for the existence of defensive controllers that automatically defeat such adversarial agents are derived. These conditions are stated in terms of skeleton matrices - matrices of zeros and ones obtained directly from the given description of the asynchronous sequential machine being protected. When defensive controllers exist, a procedure for their design is outlined.

  1. Output gear of automatic transmission

    SciTech Connect

    Ideta, Y.; Miida, S.

    1986-12-16

    An automatic transmission is described for a front engine, front wheel drive vehicle, comprising: a torque converter; a main power train comprising a rotatory terminal member, the main power train being connected with the torque converter for transmitting a driving torque from the torque converter to the terminal member; housing means enclosing the main power train, the housing means having a cylindrical bore and at least one oil feed passage opening in a cylindrical surface of the bore, and an output gear rotatably supported by the housing means and connected detachably with the terminal member of the main power train for transmitting the driving torque from the main power train to front wheels of the vehicle. The main power train is placed between the torque converter and the output gear, the output gear having a hub which is splined detachably to the terminal member, and which is fitting in the bore of the housing means in such a manner that the hub can rotate in the bore. The hub has an annular groove formed on an outer cylindrical surface of the hub, the output gear being formed with lubricating means extending from the annular groove for conveying oil from the annular groove, the oil feed passage of the housing means opening into the annular groove for supplying oil into the lubricating means through the annular groove. The annular groove has sufficient depth and width within a range permitted by a strength of the hub to prevent a shortage of the oil supply through the annular groove to the lubricating means due to a centrifugal force of the oil rotating in the annular groove together with walls of the annular groove.

  2. Traceability Through Automatic Program Generation

    NASA Technical Reports Server (NTRS)

    Richardson, Julian; Green, Jeff

    2003-01-01

    Program synthesis is a technique for automatically deriving programs from specifications of their behavior. One of the arguments made in favour of program synthesis is that it allows one to trace from the specification to the program. One way in which traceability information can be derived is to augment the program synthesis system so that manipulations and calculations it carries out during the synthesis process are annotated with information on what the manipulations and calculations were and why they were made. This information is then accumulated throughout the synthesis process, at the end of which, every artifact produced by the synthesis is annotated with a complete history relating it to every other artifact (including the source specification) which influenced its construction. This approach requires modification of the entire synthesis system - which is labor-intensive and hard to do without influencing its behavior. In this paper, we introduce a novel, lightweight technique for deriving traceability from a program specification to the corresponding synthesized code. Once a program has been successfully synthesized from a specification, small changes are systematically made to the specification and the effects on the synthesized program observed. We have partially automated the technique and applied it in an experiment to one of our program synthesis systems, AUTOFILTER, and to the GNU C compiler, GCC. The results are promising: 1. Manual inspection of the results indicates that most of the connections derived from the source (a specification in the case of AUTOFILTER, C source code in the case of GCC) to its generated target (C source code in the case of AUTOFILTER, assembly language code in the case of GCC) are correct. 2. Around half of the lines in the target can be traced to at least one line of the source. 3. Small changes in the source often induce only small changes in the target.

  3. Automatic mathematical modeling for space application

    NASA Technical Reports Server (NTRS)

    Wang, Caroline K.

    1987-01-01

    A methodology for automatic mathematical modeling is described. The major objective is to create a very friendly environment for engineers to design, maintain and verify their model and also automatically convert the mathematical model into FORTRAN code for conventional computation. A demonstration program was designed for modeling the Space Shuttle Main Engine simulation mathematical model called Propulsion System Automatic Modeling (PSAM). PSAM provides a very friendly and well organized environment for engineers to build a knowledge base for base equations and general information. PSAM contains an initial set of component process elements for the Space Shuttle Main Engine simulation and a questionnaire that allows the engineer to answer a set of questions to specify a particular model. PSAM is then able to automatically generate the model and the FORTRAN code. A future goal is to download the FORTRAN code to the VAX/VMS system for conventional computation.

  4. Automatic program debugging for intelligent tutoring systems

    SciTech Connect

    Murray, W.R.

    1986-01-01

    This thesis explores the process by which student programs can be automatically debugged in order to increase the instructional capabilities of these systems. This research presents a methodology and implementation for the diagnosis and correction of nontrivial recursive programs. In this approach, recursive programs are debugged by repairing induction proofs in the Boyer-Moore Logic. The potential of a program debugger to automatically debug widely varying novice programs in a nontrivial domain is proportional to its capabilities to reason about computational semantics. By increasing these reasoning capabilities a more powerful and robust system can result. This thesis supports these claims by examining related work in automated program debugging and by discussing the design, implementation, and evaluation of Talus, an automatic degugger for LISP programs. Talus relies on its abilities to reason about computational semantics to perform algorithm recognition, infer code teleology, and to automatically detect and correct nonsyntactic errors in student programs written in a restricted, but nontrivial, subset of LISP.

  5. Low distortion automatic phase control circuit

    NASA Technical Reports Server (NTRS)

    Hauge, G.; Pederson, C. W.

    1972-01-01

    Circuit for generation and demodulation of quadrature double side band signals in frequency division multiplexing system is described. Circuit is designed to produce low distortion automatic phase control. Illustration of circuit and components is included.

  6. Variable load automatically tests dc power supplies

    NASA Technical Reports Server (NTRS)

    Burke, H. C., Jr.; Sullivan, R. M.

    1965-01-01

    Continuously variable load automatically tests dc power supplies over an extended current range. External meters monitor current and voltage, and multipliers at the outputs facilitate plotting the power curve of the unit.

  7. Computer systems for automatic earthquake detection

    USGS Publications Warehouse

    Stewart, S.W.

    1974-01-01

    U.S Geological Survey seismologists in Menlo park, California, are utilizing the speed, reliability, and efficiency of minicomputers to monitor seismograph stations and to automatically detect earthquakes. An earthquake detection computer system, believed to be the only one of its kind in operation, automatically reports about 90 percent of all local earthquakes recorded by a network of over 100 central California seismograph stations. The system also monitors the stations for signs of malfunction or abnormal operation. Before the automatic system was put in operation, all of the earthquakes recorded had to be detected by manually searching the records, a time-consuming process. With the automatic detection system, the stations are efficiently monitored continuously. 

  8. Automaticity in social-cognitive processes.

    PubMed

    Bargh, John A; Schwader, Kay L; Hailey, Sarah E; Dyer, Rebecca L; Boothby, Erica J

    2012-12-01

    Over the past several years, the concept of automaticity of higher cognitive processes has permeated nearly all domains of psychological research. In this review, we highlight insights arising from studies in decision-making, moral judgments, close relationships, emotional processes, face perception and social judgment, motivation and goal pursuit, conformity and behavioral contagion, embodied cognition, and the emergence of higher-level automatic processes in early childhood. Taken together, recent work in these domains demonstrates that automaticity does not result exclusively from a process of skill acquisition (in which a process always begins as a conscious and deliberate one, becoming capable of automatic operation only with frequent use) - there are evolved substrates and early childhood learning mechanisms involved as well.

  9. Automatic Evolution of Molecular Nanotechnology Designs

    NASA Technical Reports Server (NTRS)

    Globus, Al; Lawton, John; Wipke, Todd; Saini, Subhash (Technical Monitor)

    1998-01-01

    This paper describes strategies for automatically generating designs for analog circuits at the molecular level. Software maps out the edges and vertices of potential nanotechnology systems on graphs, then selects appropriate ones through evolutionary or genetic paradigms.

  10. Automatic water inventory, collecting, and dispensing unit

    NASA Technical Reports Server (NTRS)

    Hall, J. B., Jr.; Williams, E. F.

    1972-01-01

    Two cylindrical tanks with piston bladders and associated components for automatic filling and emptying use liquid inventory readout devices in control of water flow. Unit provides for adaptive water collection, storage, and dispensation in weightlessness environment.

  11. A Versatile, Automatic Chromatographic Column Packing Device

    ERIC Educational Resources Information Center

    Barry, Eugene F.; And Others

    1977-01-01

    Describes an inexpensive apparatus for packing liquid and gas chromatographic columns of high efficiency. Consists of stainless steel support struts, an Automat Getriebmotor, and an associated three-pulley system capable of 10, 30, and 300 rpm. (MLH)

  12. Gear drive automatically indexes rotary table

    NASA Technical Reports Server (NTRS)

    Johns, M. F.

    1966-01-01

    Combination indexer and drive unit drills equally spaced circular hole patterns on rotary tables. It automatically rotates the table a distance exactly equal to one hole spacing for each revolution of a special idler gear.

  13. Three layered framework for automatic service composition

    NASA Astrophysics Data System (ADS)

    Liu, Xinqiong; Xia, Ping; Wan, Junli

    2009-10-01

    For automatic service composition, a planning based framework MOCIS is proposed. Planning is based on two major techniques, service reasoning and constraint satisfaction. Constraint satisfaction can be divided into quality constraint satisfaction and quantity constraint satisfaction. Contrary to traditional methods realizing upon techniques by interleaving activity, message and provider, the novelty of the framework is dividing these concerns into three layers, with activity layer majoring service reasoning, message layer for quality constraint and provider layer for quantity constraint. The layered architecture makes automatic web service composition possible for activity tree that abstract BPEL list and concrete BPEL list are achieved automatically with each layer, and users can selection proper abstract BPEL or BPEL to satisfy their request. And E-traveling composition cases have been tested, demonstrating that complex service can be achieved through three layers compositing automatically.

  14. Automatic calibration system for pressure transducers

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Fifty-channel automatic pressure transducer calibration system increases quantity and accuracy for test evaluation calibration. The pressure transducers are installed in an environmental tests chamber and manifolded to connect them to a pressure balance which is uniform.

  15. An automatic LCD panel quality detection system

    NASA Astrophysics Data System (ADS)

    Guo, Bianfang; Hou, Wenguang; Ding, Mingyue

    2009-10-01

    Automatic detection using computer vision expands rapidly along with the development of image processing technology. In this paper, we developed a rapid LCD quality detection system for automobile instrument panel production, which has wide range of usage and good stability.Our automatic detection system consists of four parts: panel fixture, signal generator module, image acquisition module and image processing software. Experiments demonstrated that our system is feasible, efficient and fast compared to manual detection.

  16. Automatic Refilling System For Liquid Helium

    NASA Technical Reports Server (NTRS)

    Serlemitsos, Aristides; Sansebastian, Mark; Geagen, Jay; Warner, Brent

    1990-01-01

    Cryogenic experiments left unattended for days. System automatically replenishes liquid helium in cryogenic experimental apparatus as liquid evaporates. Automatic filling system transfers liquid helium from storage vessel to experimental apparatus under computer control. Gaseous helium from cylinder supplies pumping pressure. Circuit senses level of liquid helium by sensing voltage across measuring resistors in series with silicon resistance thermometers (SRT's). Low voltage indicates SRT covered, while high voltage indicates uncovered.

  17. Automatic safety rod for reactors. [LMFBR

    DOEpatents

    Germer, J.H.

    1982-03-23

    An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

  18. UMLS-based automatic image indexing.

    PubMed

    Sneiderman, C; Sneiderman, Charles Alan; Demner-Fushman, D; Demner-Fushman, Dina; Fung, K W; Fung, Kin Wah; Bray, B; Bray, Bruce

    2008-01-01

    To date, most accurate image retrieval techniques rely on textual descriptions of images. Our goal is to automatically generate indexing terms for an image extracted from a biomedical article by identifying Unified Medical Language System (UMLS) concepts in image caption and its discussion in the text. In a pilot evaluation of the suggested image indexing method by five physicians, a third of the automatically identified index terms were found suitable for indexing.

  19. Production from multiple zones of a tar sands formation

    DOEpatents

    Karanikas, John Michael; Vinegar, Harold J

    2013-02-26

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. Fluids are produced from the formation through at least one production well that is located in at least two zones in the formation. The first zone has an initial permeability of at least 1 darcy. The second zone has an initial of at most 0.1 darcy. The two zones are separated by a substantially impermeable barrier.

  20. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000...

  1. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000...

  2. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000...

  3. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000...

  4. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000...

  5. 46 CFR 52.01-10 - Automatic controls.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Automatic controls. 52.01-10 Section 52.01-10 Shipping... Requirements § 52.01-10 Automatic controls. (a) Each main boiler must meet the special requirements for automatic safety controls in § 62.35-20(a)(1) of this chapter. (b) Each automatically controlled...

  6. 46 CFR 52.01-10 - Automatic controls.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Automatic controls. 52.01-10 Section 52.01-10 Shipping... Requirements § 52.01-10 Automatic controls. (a) Each main boiler must meet the special requirements for automatic safety controls in § 62.35-20(a)(1) of this chapter. (b) Each automatically controlled...

  7. 46 CFR 52.01-10 - Automatic controls.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Automatic controls. 52.01-10 Section 52.01-10 Shipping... Requirements § 52.01-10 Automatic controls. (a) Each main boiler must meet the special requirements for automatic safety controls in § 62.35-20(a)(1) of this chapter. (b) Each automatically controlled...

  8. 14 CFR 23.1329 - Automatic pilot system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Automatic pilot system. 23.1329 Section 23...: Installation § 23.1329 Automatic pilot system. If an automatic pilot system is installed, it must meet the following: (a) Each system must be designed so that the automatic pilot can— (1) Be quickly and...

  9. The Importance of Automaticity for Developing Expertise in Reading.

    ERIC Educational Resources Information Center

    Samuels, S. Jay; Flor, Richard F.

    1997-01-01

    Discusses how students become automatic at reading sub-skills, the indicators that can be used to determine whether a student is automatic, and the psychological mechanisms that allow students to perform complex skills automatically. Discusses implications of automaticity research for teaching reading. (RS)

  10. 7 CFR 58.418 - Automatic cheese making equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Automatic cheese making equipment. 58.418 Section 58... Service 1 Equipment and Utensils § 58.418 Automatic cheese making equipment. (a) Automatic Curd Maker. The automatic curd making system shall be constructed of stainless steel or of material approved in the...

  11. 7 CFR 58.418 - Automatic cheese making equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Automatic cheese making equipment. 58.418 Section 58... Service 1 Equipment and Utensils § 58.418 Automatic cheese making equipment. (a) Automatic Curd Maker. The automatic curd making system shall be constructed of stainless steel or of material approved in the...

  12. 7 CFR 58.418 - Automatic cheese making equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Automatic cheese making equipment. 58.418 Section 58... Service 1 Equipment and Utensils § 58.418 Automatic cheese making equipment. (a) Automatic Curd Maker. The automatic curd making system shall be constructed of stainless steel or of material approved in the...

  13. 7 CFR 58.418 - Automatic cheese making equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Automatic cheese making equipment. 58.418 Section 58... Service 1 Equipment and Utensils § 58.418 Automatic cheese making equipment. (a) Automatic Curd Maker. The automatic curd making system shall be constructed of stainless steel or of material approved in the...

  14. 7 CFR 58.418 - Automatic cheese making equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Automatic cheese making equipment. 58.418 Section 58... Service 1 Equipment and Utensils § 58.418 Automatic cheese making equipment. (a) Automatic Curd Maker. The automatic curd making system shall be constructed of stainless steel or of material approved in the...

  15. 10 CFR 429.45 - Automatic commercial ice makers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Automatic commercial ice makers. 429.45 Section 429.45... PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.45 Automatic commercial ice makers. (a... automatic commercial ice makers; and (2) For each basic model of automatic commercial ice maker selected...

  16. 10 CFR 429.45 - Automatic commercial ice makers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Automatic commercial ice makers. 429.45 Section 429.45... PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.45 Automatic commercial ice makers. (a... automatic commercial ice makers; and (2) For each basic model of automatic commercial ice maker selected...

  17. 10 CFR 429.45 - Automatic commercial ice makers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Automatic commercial ice makers. 429.45 Section 429.45... PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.45 Automatic commercial ice makers. (a... automatic commercial ice makers; and (2) For each basic model of automatic commercial ice maker selected...

  18. 46 CFR 52.01-10 - Automatic controls.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Automatic controls. 52.01-10 Section 52.01-10 Shipping... Requirements § 52.01-10 Automatic controls. (a) Each main boiler must meet the special requirements for automatic safety controls in § 62.35-20(a)(1) of this chapter. (b) Each automatically controlled...

  19. 14 CFR 23.1329 - Automatic pilot system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Automatic pilot system. 23.1329 Section 23...: Installation § 23.1329 Automatic pilot system. If an automatic pilot system is installed, it must meet the following: (a) Each system must be designed so that the automatic pilot can— (1) Be quickly and...

  20. Practical automatic Arabic license plate recognition system

    NASA Astrophysics Data System (ADS)

    Mohammad, Khader; Agaian, Sos; Saleh, Hani

    2011-02-01

    Since 1970's, the need of an automatic license plate recognition system, sometimes referred as Automatic License Plate Recognition system, has been increasing. A license plate recognition system is an automatic system that is able to recognize a license plate number, extracted from image sensors. In specific, Automatic License Plate Recognition systems are being used in conjunction with various transportation systems in application areas such as law enforcement (e.g. speed limit enforcement) and commercial usages such as parking enforcement and automatic toll payment private and public entrances, border control, theft and vandalism control. Vehicle license plate recognition has been intensively studied in many countries. Due to the different types of license plates being used, the requirement of an automatic license plate recognition system is different for each country. [License plate detection using cluster run length smoothing algorithm ].Generally, an automatic license plate localization and recognition system is made up of three modules; license plate localization, character segmentation and optical character recognition modules. This paper presents an Arabic license plate recognition system that is insensitive to character size, font, shape and orientation with extremely high accuracy rate. The proposed system is based on a combination of enhancement, license plate localization, morphological processing, and feature vector extraction using the Haar transform. The performance of the system is fast due to classification of alphabet and numerals based on the license plate organization. Experimental results for license plates of two different Arab countries show an average of 99 % successful license plate localization and recognition in a total of more than 20 different images captured from a complex outdoor environment. The results run times takes less time compared to conventional and many states of art methods.

  1. Attention to Automatic Movements in Parkinson's Disease: Modified Automatic Mode in the Striatum

    PubMed Central

    Wu, Tao; Liu, Jun; Zhang, Hejia; Hallett, Mark; Zheng, Zheng; Chan, Piu

    2015-01-01

    We investigated neural correlates when attending to a movement that could be made automatically in healthy subjects and Parkinson's disease (PD) patients. Subjects practiced a visuomotor association task until they could perform it automatically, and then directed their attention back to the automated task. Functional MRI was obtained during the early-learning, automatic stage, and when re-attending. In controls, attention to automatic movement induced more activation in the dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex, and rostral supplementary motor area. The motor cortex received more influence from the cortical motor association regions. In contrast, the pattern of the activity and connectivity of the striatum remained at the level of the automatic stage. In PD patients, attention enhanced activity in the DLPFC, premotor cortex, and cerebellum, but the connectivity from the putamen to the motor cortex decreased. Our findings demonstrate that, in controls, when a movement achieves the automatic stage, attention can influence the attentional networks and cortical motor association areas, but has no apparent effect on the striatum. In PD patients, attention induces a shift from the automatic mode back to the controlled pattern within the striatum. The shifting between controlled and automatic behaviors relies in part on striatal function. PMID:24925772

  2. Automatic imitation is reduced in narcissists.

    PubMed

    Obhi, Sukhvinder S; Hogeveen, Jeremy; Giacomin, Miranda; Jordan, Christian H

    2014-06-01

    Narcissism is a personality trait that has been extensively studied in normal populations. Individuals high on subclinical narcissism tend to display an excessive self-focus and reduced concern for others. Does their disregard of others have roots in low-level processes of social perception? We investigated whether narcissism is related to the automatic imitation of observed actions. In the automatic imitation task, participants make cued actions in the presence of action videos displaying congruent or incongruent actions. The difference in response times and accuracy between congruent and incongruent trials (i.e., the interference effect) is a behavioral index of motor resonance in the brain-a process whereby observed actions activate matching motor representations in the observer. We found narcissism to be negatively related to interference in the automatic imitation task, such that high narcissism is associated with reduced imitation. Thus, levels of narcissism predict differences in the tendency to automatically resonate with others, and the pattern of data we observe suggests that a key difference is that high narcissists possess an improved ability to suppress automatic imitation when such imitation would be detrimental to task performance. To the extent that motor resonance is a product of a human mirror system, our data constitute evidence for a link between narcissistic tendencies and mirror system functioning. PMID:23957308

  3. Automatic Fastening Large Structures: a New Approach

    NASA Technical Reports Server (NTRS)

    Lumley, D. F.

    1985-01-01

    The external tank (ET) intertank structure for the space shuttle, a 27.5 ft diameter 22.5 ft long externally stiffened mechanically fastened skin-stringer-frame structure, was a labor intensitive manual structure built on a modified Saturn tooling position. A new approach was developed based on half-section subassemblies. The heart of this manufacturing approach will be 33 ft high vertical automatic riveting system with a 28 ft rotary positioner coming on-line in mid 1985. The Automatic Riveting System incorporates many of the latest automatic riveting technologies. Key features include: vertical columns with two sets of independently operating CNC drill-riveting heads; capability of drill, insert and upset any one piece fastener up to 3/8 inch diameter including slugs without displacing the workpiece offset bucking ram with programmable rotation and deep retraction; vision system for automatic parts program re-synchronization and part edge margin control; and an automatic rivet selection/handling system.

  4. Automatic prejudice in childhood and early adolescence.

    PubMed

    Degner, Juliane; Wentura, Dirk

    2010-03-01

    Four cross-sectional studies are presented that investigated the automatic activation of prejudice in children and adolescents (aged 9 years to 15 years). Therefore, 4 different versions of the affective priming task were used, with pictures of ingroup and outgroup members being presented as prejudice-related prime stimuli. In all 4 studies, a pattern occurred that suggests a linear developmental increase of automatic prejudice with significant effects of outgroup negativity appearing only around the ages of 12 to 13 years. Results of younger children, on the contrary, did not indicate any effect of automatic prejudice activation. In contrast, prejudice effects in an Implicit Association Test (IAT) showed high levels of prejudice independent of age (Study 3). Results of Study 4 suggest that these age differences are due to age-related differences in spontaneous categorization processes. Introducing a forced-categorization into the affective priming procedure produced a pattern of results equivalent to that obtained with the IAT. These results suggest that although children are assumed to acquire prejudice at much younger ages, automatization of such attitudes might be related to developmental processes in early adolescence. We discuss possible theoretical implications of these results for a developmental theory of prejudice representation and automatization during childhood and adolescence. PMID:20175618

  5. Automatic contrast: evidence that automatic comparison with the social self affects evaluative responses.

    PubMed

    Ruys, Kirsten I; Spears, Russell; Gordijn, Ernestine H; de Vries, Nanne K

    2007-08-01

    The aim of the present research was to investigate whether unconsciously presented affective information may cause opposite evaluative responses depending on what social category the information originates from. We argue that automatic comparison processes between the self and the unconscious affective information produce this evaluative contrast effect. Consistent with research on automatic behaviour, we propose that when an intergroup context is activated, an automatic comparison to the social self may determine the automatic evaluative responses, at least for highly visible categories (e.g. sex, ethnicity). Contrary to previous research on evaluative priming, we predict automatic contrastive responses to affective information originating from an outgroup category such that the evaluative response to neutral targets is opposite to the valence of the suboptimal primes. Two studies using different intergroup contexts provide support for our hypotheses. PMID:17705936

  6. Automatic CT Measurement In Lumbar Vertebrae

    NASA Astrophysics Data System (ADS)

    Bisseling, Johannes T.; van Erning, Leon J. T. O.; Schouten, Theo E.; Lemmen, J. Albert M.

    1989-04-01

    Reliable software for automatic determination of the border between the cancellous bone and the cortical bone of lumbar vertebrae has been developed. An automatic procedure is needed because calculations in a larger series of patient data take too much time due to the inevitable human interaction required by available software packages. Processing in batch mode is essential. An important advantage of automatic outlining is its reproducibility, because only a single technique with objective criteria is used. In a so-called Region Of Interest (ROI) texture analysis can be performed to quantify the condition of the vertebral body in order to diagnose osteoporosis. This technique may be an alternative to a classification based solely on the average X-ray absorption value.

  7. Automatic welding of stainless steel tubing

    NASA Technical Reports Server (NTRS)

    Clautice, W. E.

    1978-01-01

    The use of automatic welding for making girth welds in stainless steel tubing was investigated as well as the reduction in fabrication costs resulting from the elimination of radiographic inspection. Test methodology, materials, and techniques are discussed, and data sheets for individual tests are included. Process variables studied include welding amperes, revolutions per minute, and shielding gas flow. Strip chart recordings, as a definitive method of insuring weld quality, are studied. Test results, determined by both radiographic and visual inspection, are presented and indicate that once optimum welding procedures for specific sizes of tubing are established, and the welding machine operations are certified, then the automatic tube welding process produces good quality welds repeatedly, with a high degree of reliability. Revised specifications for welding tubing using the automatic process and weld visual inspection requirements at the Kennedy Space Center are enumerated.

  8. Support vector machine for automatic pain recognition

    NASA Astrophysics Data System (ADS)

    Monwar, Md Maruf; Rezaei, Siamak

    2009-02-01

    Facial expressions are a key index of emotion and the interpretation of such expressions of emotion is critical to everyday social functioning. In this paper, we present an efficient video analysis technique for recognition of a specific expression, pain, from human faces. We employ an automatic face detector which detects face from the stored video frame using skin color modeling technique. For pain recognition, location and shape features of the detected faces are computed. These features are then used as inputs to a support vector machine (SVM) for classification. We compare the results with neural network based and eigenimage based automatic pain recognition systems. The experiment results indicate that using support vector machine as classifier can certainly improve the performance of automatic pain recognition system.

  9. Automatic weld torch guidance control system

    NASA Technical Reports Server (NTRS)

    Smaith, H. E.; Wall, W. A.; Burns, M. R., Jr.

    1982-01-01

    A highly reliable, fully digital, closed circuit television optical, type automatic weld seam tracking control system was developed. This automatic tracking equipment is used to reduce weld tooling costs and increase overall automatic welding reliability. The system utilizes a charge injection device digital camera which as 60,512 inidividual pixels as the light sensing elements. Through conventional scanning means, each pixel in the focal plane is sequentially scanned, the light level signal digitized, and an 8-bit word transmitted to scratch pad memory. From memory, the microprocessor performs an analysis of the digital signal and computes the tracking error. Lastly, the corrective signal is transmitted to a cross seam actuator digital drive motor controller to complete the closed loop, feedback, tracking system. This weld seam tracking control system is capable of a tracking accuracy of + or - 0.2 mm, or better. As configured, the system is applicable to square butt, V-groove, and lap joint weldments.

  10. Automatic metro map layout using multicriteria optimization.

    PubMed

    Stott, Jonathan; Rodgers, Peter; Martínez-Ovando, Juan Carlos; Walker, Stephen G

    2011-01-01

    This paper describes an automatic mechanism for drawing metro maps. We apply multicriteria optimization to find effective placement of stations with a good line layout and to label the map unambiguously. A number of metrics are defined, which are used in a weighted sum to find a fitness value for a layout of the map. A hill climbing optimizer is used to reduce the fitness value, and find improved map layouts. To avoid local minima, we apply clustering techniques to the map-the hill climber moves both stations and clusters when finding improved layouts. We show the method applied to a number of metro maps, and describe an empirical study that provides some quantitative evidence that automatically-drawn metro maps can help users to find routes more efficiently than either published maps or undistorted maps. Moreover, we have found that, in these cases, study subjects indicate a preference for automatically-drawn maps over the alternatives.

  11. Automatic alignment method for calibration of hydrometers

    NASA Astrophysics Data System (ADS)

    Lee, Y. J.; Chang, K. H.; Chon, J. C.; Oh, C. Y.

    2004-04-01

    This paper presents a new method to automatically align specific scale-marks for the calibration of hydrometers. A hydrometer calibration system adopting the new method consists of a vision system, a stepping motor, and software to control the system. The vision system is composed of a CCD camera and a frame grabber, and is used to acquire images. The stepping motor moves the camera, which is attached to the vessel containing a reference liquid, along the hydrometer. The operating program has two main functions: to process images from the camera to find the position of the horizontal plane and to control the stepping motor for the alignment of the horizontal plane with a particular scale-mark. Any system adopting this automatic alignment method is a convenient and precise means of calibrating a hydrometer. The performance of the proposed method is illustrated by comparing the calibration results using the automatic alignment method with those obtained using the manual method.

  12. Automatic discrimination of emotion from spoken Finnish.

    PubMed

    Toivanen, Juhani; Väyrynen, Eero; Seppänen, Tapio

    2004-01-01

    In this paper, experiments on the automatic discrimination of basic emotions from spoken Finnish are described. For the purpose of the study, a large emotional speech corpus of Finnish was collected; 14 professional actors acted as speakers, and simulated four primary emotions when reading out a semantically neutral text. More than 40 prosodic features were derived and automatically computed from the speech samples. Two application scenarios were tested: the first scenario was speaker-independent for a small domain of speakers while the second scenario was completely speaker-independent. Human listening experiments were conducted to assess the perceptual adequacy of the emotional speech samples. Statistical classification experiments indicated that, with the optimal combination of prosodic feature vectors, automatic emotion discrimination performance close to human emotion recognition ability was achievable. PMID:16038449

  13. An Automatic Speed Control for Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Zahm, A F

    1928-01-01

    Described here is an automatic control that has been used in several forms in wind tunnels at the Washington Navy Yard. The form now in use with the 8-foot tunnel at the Navy Yard is considered here. Details of the design and operation of the automatic control system are given. Leads from a Pitot tube are joined to an inverted cup manometer located above a rheostat. When the sliding weight of this instrument is set to a given notch, say for 40 m.p.h, the beam tip vibrates between two electric contacts that feed the little motor. Thus, when the wind is too strong or too weak, the motor automatically throws the rheostat slide forward and backward. If it failed to function well, the operator would notice the effect on his meniscus, and would operate the hand control by merely pressing the switch.

  14. Automatically processed alpha-track radon monitor

    DOEpatents

    Langner, Jr., G. Harold

    1993-01-01

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

  15. Automatically processed alpha-track radon monitor

    DOEpatents

    Langner, G.H. Jr.

    1993-01-12

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

  16. Automatic gisting systems for voice communications

    NASA Astrophysics Data System (ADS)

    Maksymowicz, A. T.

    It is pointed out that the detection of a limited number of key words in voice communications, combined with nonlinguistic cues and situation knowledge, holds out the promise for automatic extraction of the general content or gist of the transmitted messages. A systems-level description of an end-to-end automatic gisting system for screening voice communications is presented. The emphasis is on identifying information which can usefully supplement the detected key words in the gisting process. Principal subsystems are identified, and their functions are discussed in the context of an overall system architecture. The example of automatic determination of aircraft takeoffs and landings at an airport, based on monitoring conversations between pilots and air traffic controllers, is used for illustrative purposes.

  17. Automatic exposure control for space sequential camera

    NASA Technical Reports Server (NTRS)

    Mcatee, G. E., Jr.; Stoap, L. J.; Solheim, C. D.; Sharpsteen, J. T.

    1975-01-01

    The final report for the automatic exposure control study for space sequential cameras, for the NASA Johnson Space Center is presented. The material is shown in the same sequence that the work was performed. The purpose of the automatic exposure control is to automatically control the lens iris as well as the camera shutter so that the subject is properly exposed on the film. A study of design approaches is presented. Analysis of the light range of the spectrum covered indicates that the practical range would be from approximately 20 to 6,000 foot-lamberts, or about nine f-stops. Observation of film available from space flights shows that optimum scene illumination is apparently not present in vehicle interior photography as well as in vehicle-to-vehicle situations. The evaluation test procedure for a breadboard, and the results, which provided information for the design of a brassboard are given.

  18. Automatic Welding of Stainless Steel Tubing

    NASA Technical Reports Server (NTRS)

    Clautice, W. E.

    1978-01-01

    To determine if the use of automatic welding would allow reduction of the radiographic inspection requirement, and thereby reduce fabrication costs, a series of welding tests were performed. In these tests an automatic welder was used on stainless steel tubing of 1/2, 3/4, and 1/2 inch diameter size. The optimum parameters were investigated to determine how much variation from optimum in machine settings could be tolerate and still result in a good quality weld. The process variables studied were the welding amperes, the revolutions per minute as a function of the circumferential weld travel speed, and the shielding gas flow. The investigation showed that the close control of process variables in conjunction with a thorough visual inspection of welds can be relied upon as an acceptable quality assurance procedure, thus permitting the radiographic inspection to be reduced by a large percentage when using the automatic process.

  19. Automatic identification of species with neural networks.

    PubMed

    Hernández-Serna, Andrés; Jiménez-Segura, Luz Fernanda

    2014-01-01

    A new automatic identification system using photographic images has been designed to recognize fish, plant, and butterfly species from Europe and South America. The automatic classification system integrates multiple image processing tools to extract the geometry, morphology, and texture of the images. Artificial neural networks (ANNs) were used as the pattern recognition method. We tested a data set that included 740 species and 11,198 individuals. Our results show that the system performed with high accuracy, reaching 91.65% of true positive fish identifications, 92.87% of plants and 93.25% of butterflies. Our results highlight how the neural networks are complementary to species identification.

  20. Automatic Control Of Length Of Welding Arc

    NASA Technical Reports Server (NTRS)

    Iceland, William F.

    1991-01-01

    Nonlinear relationships among current, voltage, and length stored in electronic memory. Conceptual microprocessor-based control subsystem maintains constant length of welding arc in gas/tungsten arc-welding system, even when welding current varied. Uses feedback of current and voltage from welding arc. Directs motor to set position of torch according to previously measured relationships among current, voltage, and length of arc. Signal paths marked "calibration" or "welding" used during those processes only. Other signal paths used during both processes. Control subsystem added to existing manual or automatic welding system equipped with automatic voltage control.

  1. Automatic reading of hybridization filter images.

    PubMed

    Audic, S; Zanetti, G

    1995-10-01

    We describe a new technique for the automatic detection and characterization, in terms of location, size and intensity, of positive hybridization spots on hybridization filter images. We will also discuss how this information can be used to reconstruct the spot deposition pattern on the filter and thus identify the spots. The part of the algorithm dedicated to the detection of spots is derived from a technique used in astronomy for the automatic recognition of galaxies on photographic plates. This technique has been modified so that it becomes able to cope with the strongly varying background typical of hybridization filter images. The technique does not require any human intervention.

  2. Automatic cell counting with ImageJ.

    PubMed

    Grishagin, Ivan V

    2015-03-15

    Cell counting is an important routine procedure. However, to date there is no comprehensive, easy to use, and inexpensive solution for routine cell counting, and this procedure usually needs to be performed manually. Here, we report a complete solution for automatic cell counting in which a conventional light microscope is equipped with a web camera to obtain images of a suspension of mammalian cells in a hemocytometer assembly. Based on the ImageJ toolbox, we devised two algorithms to automatically count these cells. This approach is approximately 10 times faster and yields more reliable and consistent results compared with manual counting.

  3. Automatic emotional expression analysis from eye area

    NASA Astrophysics Data System (ADS)

    Akkoç, Betül; Arslan, Ahmet

    2015-02-01

    Eyes play an important role in expressing emotions in nonverbal communication. In the present study, emotional expression classification was performed based on the features that were automatically extracted from the eye area. Fırst, the face area and the eye area were automatically extracted from the captured image. Afterwards, the parameters to be used for the analysis through discrete wavelet transformation were obtained from the eye area. Using these parameters, emotional expression analysis was performed through artificial intelligence techniques. As the result of the experimental studies, 6 universal emotions consisting of expressions of happiness, sadness, surprise, disgust, anger and fear were classified at a success rate of 84% using artificial neural networks.

  4. Automatic identification of species with neural networks

    PubMed Central

    Jiménez-Segura, Luz Fernanda

    2014-01-01

    A new automatic identification system using photographic images has been designed to recognize fish, plant, and butterfly species from Europe and South America. The automatic classification system integrates multiple image processing tools to extract the geometry, morphology, and texture of the images. Artificial neural networks (ANNs) were used as the pattern recognition method. We tested a data set that included 740 species and 11,198 individuals. Our results show that the system performed with high accuracy, reaching 91.65% of true positive fish identifications, 92.87% of plants and 93.25% of butterflies. Our results highlight how the neural networks are complementary to species identification. PMID:25392749

  5. Feedback Improvement in Automatic Program Evaluation Systems

    ERIC Educational Resources Information Center

    Skupas, Bronius

    2010-01-01

    Automatic program evaluation is a way to assess source program files. These techniques are used in learning management environments, programming exams and contest systems. However, use of automated program evaluation encounters problems: some evaluations are not clear for the students and the system messages do not show reasons for lost points.…

  6. Automatic Positioning System of Small Agricultural Robot

    NASA Astrophysics Data System (ADS)

    Momot, M. V.; Proskokov, A. V.; Natalchenko, A. S.; Biktimirov, A. S.

    2016-08-01

    The present article discusses automatic positioning systems of agricultural robots used in field works. The existing solutions in this area have been analyzed. The article proposes an original solution, which is easy to implement and is characterized by high- accuracy positioning.

  7. Automatic Guidance System for Welding Torches

    NASA Technical Reports Server (NTRS)

    Smith, H.; Wall, W.; Burns, M. R., Jr.

    1984-01-01

    Digital system automatically guides welding torch to produce squarebutt, V-groove and lap-joint weldments within tracking accuracy of +0.2 millimeter. Television camera observes and traverses weld joint, carrying welding torch behind. Image of joint digitized, and resulting data used to derive control signals that enable torch to track joint.

  8. Support for Debugging Automatically Parallelized Programs

    NASA Technical Reports Server (NTRS)

    Hood, Robert; Jost, Gabriele

    2001-01-01

    This viewgraph presentation provides information on support sources available for the automatic parallelization of computer program. CAPTools, a support tool developed at the University of Greenwich, transforms, with user guidance, existing sequential Fortran code into parallel message passing code. Comparison routines are then run for debugging purposes, in essence, ensuring that the code transformation was accurate.

  9. Flight Investigation of an Automatic Pitchup Control

    NASA Technical Reports Server (NTRS)

    Hurt, George J., Jr.; Whitten, James B.

    1960-01-01

    A flight investigation of an automatic pitchup control has been conducted by the National Aeronautics and Space Administration at the Langley Research Center. The pitching-moment characteristics of a transonic fighter airplane which was subject to pitchup were altered by driving the stabilizer in accordance with a signal that was a function of a combination of the measured angle of attack and the pitching velocity. An angle-of-attack threshold control was used to preset the angle of attack at which the automatic pitchup-control system would begin to drive the stabilizer. No threshold control as such existed for the pitching-velocity signal. A summing linkage in series with the pilot's longitudinal control allowed the automatic pitchup-control system to drive the stabilizer 13.5 percent of the total stabilizer travel independently of the pilot's control. Tests were made at an altitude of 35,000 feet over a Mach number range of 0.80 to 0.90. Various gearings between the control and the sensing devices were investigated. The automatic system was capable of extending the region of positive stability for the test airplane to angles of attack above the basic-airplane pitchup threshold angle of attack. In most cases a limit-cycle oscillation about the airplane pitch axis occurred.

  10. Automatic Layout Design for Power Module

    SciTech Connect

    Ning, Puqi; Wang, Fei; Ngo, Khai

    2013-01-01

    The layout of power modules is one of the key points in power module design, especially for high power densities, where couplings are increased. In this paper, along with the design example, an automatic design processes by using a genetic algorithm are presented. Some practical considerations and implementations are introduced in the optimization of module layout design.

  11. Automatic optometer operates with infrared test pattern

    NASA Technical Reports Server (NTRS)

    Cornsweet, T. N.; Crane, H. D.

    1970-01-01

    Refractive strength of human eye is monitored by optometer that automatically and continuously images infrared test pattern onto the retina. Condition of focus of the eye at any instant is determined from optometer settings needed to maintain focus of the pattern on the retina.

  12. Automatic thematic mapping in the EROS program

    NASA Technical Reports Server (NTRS)

    Edson, D. T.

    1972-01-01

    A specified approach to the automatic extraction and catographic presentation of thematic data contained in multispectral photographic images is presented. Experimental efforts were directed toward the mapping of open waters, snow and ice, infrared reflective vegetation, and massed works of man. The system must also be able to process data from a wide variety of sources.

  13. Low Speed Control for Automatic Welding

    NASA Technical Reports Server (NTRS)

    Iceland, W. E.

    1982-01-01

    Amplifier module allows rotating positioner of automatic welding machine to operate at speeds below normal range. Low speeds are precisely regulated by a servomechanism as are normal-range speeds. Addition of module to standard welding machine makes it unnecessary to purchase new equipment for low-speed welding.

  14. Automatic speech recognition in air traffic control

    NASA Technical Reports Server (NTRS)

    Karlsson, Joakim

    1990-01-01

    Automatic Speech Recognition (ASR) technology and its application to the Air Traffic Control system are described. The advantages of applying ASR to Air Traffic Control, as well as criteria for choosing a suitable ASR system are presented. Results from previous research and directions for future work at the Flight Transportation Laboratory are outlined.

  15. 42 CFR 407.17 - Automatic enrollment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SUPPLEMENTARY MEDICAL INSURANCE (SMI) ENROLLMENT AND ENTITLEMENT Individual Enrollment and Entitlement for SMI... enrolled for SMI if he or she: (1) Resides in the United States, except in Puerto Rico; (2) Becomes... chapter; and (3) Does not decline SMI enrollment. (b) Opportunity to decline automatic enrollment. (1)...

  16. Multiple Regression Analysis and Automatic Interaction Detection.

    ERIC Educational Resources Information Center

    Koplyay, Janos B.

    The Automatic Interaction Detector (AID) is discussed as to its usefulness in multiple regression analysis. The algorithm of AID-4 is a reversal of the model building process; it starts with the ultimate restricted model, namely, the whole group as a unit. By a unique splitting process maximizing the between sum of squares for the categories of…

  17. A Statistical Approach to Automatic Speech Summarization

    NASA Astrophysics Data System (ADS)

    Hori, Chiori; Furui, Sadaoki; Malkin, Rob; Yu, Hua; Waibel, Alex

    2003-12-01

    This paper proposes a statistical approach to automatic speech summarization. In our method, a set of words maximizing a summarization score indicating the appropriateness of summarization is extracted from automatically transcribed speech and then concatenated to create a summary. The extraction process is performed using a dynamic programming (DP) technique based on a target compression ratio. In this paper, we demonstrate how an English news broadcast transcribed by a speech recognizer is automatically summarized. We adapted our method, which was originally proposed for Japanese, to English by modifying the model for estimating word concatenation probabilities based on a dependency structure in the original speech given by a stochastic dependency context free grammar (SDCFG). We also propose a method of summarizing multiple utterances using a two-level DP technique. The automatically summarized sentences are evaluated by summarization accuracy based on a comparison with a manual summary of speech that has been correctly transcribed by human subjects. Our experimental results indicate that the method we propose can effectively extract relatively important information and remove redundant and irrelevant information from English news broadcasts.

  18. Automatic Assessment of 3D Modeling Exams

    ERIC Educational Resources Information Center

    Sanna, A.; Lamberti, F.; Paravati, G.; Demartini, C.

    2012-01-01

    Computer-based assessment of exams provides teachers and students with two main benefits: fairness and effectiveness in the evaluation process. This paper proposes a fully automatic evaluation tool for the Graphic and Virtual Design (GVD) curriculum at the First School of Architecture of the Politecnico di Torino, Italy. In particular, the tool is…

  19. Automatic Pilot For Flight-Test Maneuvers

    NASA Technical Reports Server (NTRS)

    Duke, Eugene L.; Jones, Frank P.; Roncoli, Ralph B.

    1992-01-01

    Autopilot replaces pilot during automatic maneuvers. Pilot, based on ground, flies aircraft to required altitude, then turns control over to autopilot. Increases quality of maneuvers significantly beyond that attainable through remote manual control by pilot on ground. Also increases quality of maneuvers because it performs maneuvers faster than pilot could and because it does not have to repeat poorly executed maneuvers.

  20. 28 CFR 17.28 - Automatic declassification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 17.28 Judicial Administration DEPARTMENT OF JUSTICE CLASSIFIED NATIONAL SECURITY INFORMATION AND... through the Department Security Officer of any specific information they propose to exempt from automatic... information exempted does not identify a confidential human source or human intelligence source. (c)...

  1. 28 CFR 17.28 - Automatic declassification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 17.28 Judicial Administration DEPARTMENT OF JUSTICE CLASSIFIED NATIONAL SECURITY INFORMATION AND... through the Department Security Officer of any specific information they propose to exempt from automatic... information exempted does not identify a confidential human source or human intelligence source. (c)...

  2. Laser tracking system with automatic reacquisition capability.

    PubMed

    Johnson, R E; Weiss, P F

    1968-06-01

    A laser based tracking system is described that has the capability of automatically performing an acquisition search to locate the target. This work is intended for precision launch phase tracking of the Saturn V launch vehicle. System tracking accuracies limited only by the atmosphere have been demonstrated, as has acquisition over a 1 degrees x 1 degrees field of view.

  3. Automatic thermographic image defect detection of composites

    NASA Astrophysics Data System (ADS)

    Luo, Bin; Liebenberg, Bjorn; Raymont, Jeff; Santospirito, SP

    2011-05-01

    Detecting defects, and especially reliably measuring defect sizes, are critical objectives in automatic NDT defect detection applications. In this work, the Sentence software is proposed for the analysis of pulsed thermography and near IR images of composite materials. Furthermore, the Sentence software delivers an end-to-end, user friendly platform for engineers to perform complete manual inspections, as well as tools that allow senior engineers to develop inspection templates and profiles, reducing the requisite thermographic skill level of the operating engineer. Finally, the Sentence software can also offer complete independence of operator decisions by the fully automated "Beep on Defect" detection functionality. The end-to-end automatic inspection system includes sub-systems for defining a panel profile, generating an inspection plan, controlling a robot-arm and capturing thermographic images to detect defects. A statistical model has been built to analyze the entire image, evaluate grey-scale ranges, import sentencing criteria and automatically detect impact damage defects. A full width half maximum algorithm has been used to quantify the flaw sizes. The identified defects are imported into the sentencing engine which then sentences (automatically compares analysis results against acceptance criteria) the inspection by comparing the most significant defect or group of defects against the inspection standards.

  4. Second-Generation Automatic Problem Grading

    ERIC Educational Resources Information Center

    Greene, Ronald L.

    2006-01-01

    Recent years have seen widespread adoption of automatic grading of physics homework problems. Although first-generation homework management systems provide feedback and assign scores based only on the answers, problem-solving performance on exams seems to be no worse for students using these systems than for those who receive detailed comments…

  5. 12 CFR 925.4 - Automatic membership.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK MEMBERS AND HOUSING ASSOCIATES... for certain charter conversions. An insured depository institution member that converts from one charter type to another automatically shall become a member of the Bank of which the...

  6. An automatic bridge for inductive voltage dividers

    SciTech Connect

    Chang, P.; Liang, C.P.; Hsiao, J.C.

    1994-12-31

    We describe an automatic, injection-type bridge for inductive voltage divider (IVD) applications at low audio frequencies. We used it to self-calibrate programmable IVDs fabricated in house, by an automated {open_quotes}boot-strap{close_quotes} procedure. It is the heart of our reference standard for ac voltage ratios as well as a calibration system for IVDs.

  7. 32 CFR 2001.30 - Automatic declassification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... provisions of the National Security Act of 1947, as amended, shall be referred to the Department of Energy... 32 National Defense 6 2011-07-01 2011-07-01 false Automatic declassification. 2001.30 Section 2001.30 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY...

  8. 32 CFR 2001.30 - Automatic declassification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... provisions of the National Security Act of 1947, as amended, shall be referred to the Department of Energy... 32 National Defense 6 2010-07-01 2010-07-01 false Automatic declassification. 2001.30 Section 2001.30 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY...

  9. 32 CFR 2001.30 - Automatic declassification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... provisions of the National Security Act of 1947, as amended, shall be referred to the Department of Energy... 32 National Defense 6 2013-07-01 2013-07-01 false Automatic declassification. 2001.30 Section 2001.30 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY...

  10. 32 CFR 2001.30 - Automatic declassification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... provisions of the National Security Act of 1947, as amended, shall be referred to the Department of Energy... 32 National Defense 6 2014-07-01 2014-07-01 false Automatic declassification. 2001.30 Section 2001.30 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY...

  11. 32 CFR 2001.30 - Automatic declassification.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... provisions of the National Security Act of 1947, as amended, shall be referred to the Department of Energy... 32 National Defense 6 2012-07-01 2012-07-01 false Automatic declassification. 2001.30 Section 2001.30 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY...

  12. Automatic Activation of Exercise and Sedentary Stereotypes

    ERIC Educational Resources Information Center

    Berry, Tanya; Spence, John C.

    2009-01-01

    We examined the automatic activation of "sedentary" and "exerciser" stereotypes using a social prime Stroop task. Results showed significantly slower response times between the exercise words and the exercise control words and between the sedentary words and the exercise control words when preceded by an attractive exerciser prime. Words preceded…

  13. Handwriting Automaticity: The Search for Performance Thresholds

    ERIC Educational Resources Information Center

    Medwell, Jane; Wray, David

    2014-01-01

    Evidence is accumulating that handwriting has an important role in written composition. In particular, handwriting automaticity appears to relate to success in composition. This relationship has been little explored in British contexts and we currently have little idea of what threshold performance levels might be. In this paper, we report on two…

  14. 38 CFR 51.31 - Automatic recognition.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Obtaining Per Diem for Nursing Home Care in... that already is recognized by VA as a State home for nursing home care at the time this part becomes effective, automatically will continue to be recognized as a State home for nursing home care but will...

  15. 38 CFR 51.31 - Automatic recognition.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Obtaining Per Diem for Nursing Home Care in... that already is recognized by VA as a State home for nursing home care at the time this part becomes effective, automatically will continue to be recognized as a State home for nursing home care but will...

  16. 38 CFR 51.31 - Automatic recognition.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Obtaining Per Diem for Nursing Home Care in... that already is recognized by VA as a State home for nursing home care at the time this part becomes effective, automatically will continue to be recognized as a State home for nursing home care but will...

  17. 38 CFR 51.31 - Automatic recognition.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Obtaining Per Diem for Nursing Home Care in... that already is recognized by VA as a State home for nursing home care at the time this part becomes effective, automatically will continue to be recognized as a State home for nursing home care but will...

  18. 38 CFR 51.31 - Automatic recognition.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Obtaining Per Diem for Nursing Home Care in... that already is recognized by VA as a State home for nursing home care at the time this part becomes effective, automatically will continue to be recognized as a State home for nursing home care but will...

  19. Automatic TLI recognition system beta prototype testing

    SciTech Connect

    Lassahn, G.D.

    1996-06-01

    This report describes the beta prototype automatic target recognition system ATR3, and some performance tests done with this system. This is a fully operational system, with a high computational speed. It is useful for findings any kind of target in digitized image data, and as a general purpose image analysis tool.

  20. RFID: A Revolution in Automatic Data Recognition

    ERIC Educational Resources Information Center

    Deal, Walter F., III

    2004-01-01

    Radio frequency identification, or RFID, is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna…

  1. A Method for Automatically Abstracting Visual Documents.

    ERIC Educational Resources Information Center

    Rorvig, Mark E.

    1993-01-01

    Describes a method for automatically selecting key frames that can be used to represent the total image sequence of visual documents. An abstracting algorithm developed at the National Aeronautics and Space Administration is explained, and extensive examples of abstracted motion sequences are presented. (eight references) (LRW)

  2. MARZ: Manual and automatic redshifting software

    NASA Astrophysics Data System (ADS)

    Hinton, S. R.; Davis, Tamara M.; Lidman, C.; Glazebrook, K.; Lewis, G. F.

    2016-04-01

    The Australian Dark Energy Survey (OzDES) is a 100-night spectroscopic survey underway on the Anglo-Australian Telescope using the fibre-fed 2-degree-field (2dF) spectrograph. We have developed a new redshifting application MARZ with greater usability, flexibility, and the capacity to analyse a wider range of object types than the RUNZ software package previously used for redshifting spectra from 2dF. MARZ is an open-source, client-based, Javascript web-application which provides an intuitive interface and powerful automatic matching capabilities on spectra generated from the AAOmega spectrograph to produce high quality spectroscopic redshift measurements. The software can be run interactively or via the command line, and is easily adaptable to other instruments and pipelines if conforming to the current FITS file standard is not possible. Behind the scenes, a modified version of the AUTOZ cross-correlation algorithm is used to match input spectra against a variety of stellar and galaxy templates, and automatic matching performance for OzDES spectra has increased from 54% (RUNZ) to 91% (MARZ). Spectra not matched correctly by the automatic algorithm can be easily redshifted manually by cycling automatic results, manual template comparison, or marking spectral features.

  3. Automatization of Student Assessment Using Multimedia Technology.

    ERIC Educational Resources Information Center

    Taniar, David; Rahayu, Wenny

    Most use of multimedia technology in teaching and learning to date has emphasized the teaching aspect only. An application of multimedia in examinations has been neglected. This paper addresses how multimedia technology can be applied to the automatization of assessment, by proposing a prototype of a multimedia question bank, which is able to…

  4. Grammatically-Based Automatic Word Class Formation

    ERIC Educational Resources Information Center

    Hirschman, Lynette; And Others

    1975-01-01

    Describes an automatic procedure which uses the syntactic relations as the basis for grouping words into classes. It forms classes by grouping together nouns that occur as subject (or object) of the same verbs, and similarly by grouping together verbs occurring with the same subject or object. (Author)

  5. A Semi-Automatic Variability Search

    NASA Astrophysics Data System (ADS)

    Maciejewski, G.; Niedzielski, A.

    Technical features of the Semi-Automatic Variability Search (SAVS) operating at the Astronomical Observatory of the Nicolaus Copernicus University and the results of the first year of observations are presented. The user-friendly software developed for reduction of acquired CCD images and detection of new variable stars is also described.

  6. Young Children's Automatic Encoding of Social Categories

    ERIC Educational Resources Information Center

    Weisman, Kara; Johnson, Marissa V.; Shutts, Kristin

    2015-01-01

    The present research investigated young children's automatic encoding of two social categories that are highly relevant to adults: gender and race. Three- to 6-year-old participants learned facts about unfamiliar target children who varied in either gender or race and were asked to remember which facts went with which targets. When participants…

  7. Automatic TLI recognition system, general description

    SciTech Connect

    Lassahn, G.D.

    1997-02-01

    This report is a general description of an automatic target recognition system developed at the Idaho National Engineering Laboratory for the Department of Energy. A user`s manual is a separate volume, Automatic TLI Recognition System, User`s Guide, and a programmer`s manual is Automatic TLI Recognition System, Programmer`s Guide. This system was designed as an automatic target recognition system for fast screening of large amounts of multi-sensor image data, based on low-cost parallel processors. This system naturally incorporates image data fusion, and it gives uncertainty estimates. It is relatively low cost, compact, and transportable. The software is easily enhanced to expand the system`s capabilities, and the hardware is easily expandable to increase the system`s speed. In addition to its primary function as a trainable target recognition system, this is also a versatile, general-purpose tool for image manipulation and analysis, which can be either keyboard-driven or script-driven. This report includes descriptions of three variants of the computer hardware, a description of the mathematical basis if the training process, and a description with examples of the system capabilities.

  8. Automatic visual inspection of hybrid microcircuits

    SciTech Connect

    Hines, R.E.

    1980-05-01

    An automatic visual inspection system using a minicomputer and a video digitizer was developed for inspecting hybrid microcircuits (HMC) and thin-film networks (TFN). The system performed well in detecting missing components on HMCs and reduced the testing time for each HMC by 75%.

  9. Semi-automatic approach for music classification

    NASA Astrophysics Data System (ADS)

    Zhang, Tong

    2003-11-01

    Audio categorization is essential when managing a music database, either a professional library or a personal collection. However, a complete automation in categorizing music into proper classes for browsing and searching is not yet supported by today"s technology. Also, the issue of music classification is subjective to some extent as each user may have his own criteria for categorizing music. In this paper, we propose the idea of semi-automatic music classification. With this approach, a music browsing system is set up which contains a set of tools for separating music into a number of broad types (e.g. male solo, female solo, string instruments performance, etc.) using existing music analysis methods. With results of the automatic process, the user may further cluster music pieces in the database into finer classes and/or adjust misclassifications manually according to his own preferences and definitions. Such a system may greatly improve the efficiency of music browsing and retrieval, while at the same time guarantee accuracy and user"s satisfaction of the results. Since this semi-automatic system has two parts, i.e. the automatic part and the manual part, they are described separately in the paper, with detailed descriptions and examples of each step of the two parts included.

  10. Automatic Collection of Rock and Soil Samples

    NASA Technical Reports Server (NTRS)

    Kyrias, G. M.

    1982-01-01

    Proposed machine would sample rock or soil automatically. Mounted on a wheeled or tracked vehicle, machine positions drill for cut at any angle from horizontal to vertical, moves power head to drive drill into cut, and stores drilled core in a container. New concept may also be useful in terrestrial agricultural and geologic surveys.

  11. Automatic spatiotemporal matching of detected pleural thickenings

    NASA Astrophysics Data System (ADS)

    Chaisaowong, Kraisorn; Keller, Simon Kai; Kraus, Thomas

    2014-01-01

    Pleural thickenings can be found in asbestos exposed patient's lung. Non-invasive diagnosis including CT imaging can detect aggressive malignant pleural mesothelioma in its early stage. In order to create a quantitative documentation of automatic detected pleural thickenings over time, the differences in volume and thickness of the detected thickenings have to be calculated. Physicians usually estimate the change of each thickening via visual comparison which provides neither quantitative nor qualitative measures. In this work, automatic spatiotemporal matching techniques of the detected pleural thickenings at two points of time based on the semi-automatic registration have been developed, implemented, and tested so that the same thickening can be compared fully automatically. As result, the application of the mapping technique using the principal components analysis turns out to be advantageous than the feature-based mapping using centroid and mean Hounsfield Units of each thickening, since the resulting sensitivity was improved to 98.46% from 42.19%, while the accuracy of feature-based mapping is only slightly higher (84.38% to 76.19%).

  12. Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

  13. Automatic River Network Extraction from LIDAR Data

    NASA Astrophysics Data System (ADS)

    Maderal, E. N.; Valcarcel, N.; Delgado, J.; Sevilla, C.; Ojeda, J. C.

    2016-06-01

    National Geographic Institute of Spain (IGN-ES) has launched a new production system for automatic river network extraction for the Geospatial Reference Information (GRI) within hydrography theme. The goal is to get an accurate and updated river network, automatically extracted as possible. For this, IGN-ES has full LiDAR coverage for the whole Spanish territory with a density of 0.5 points per square meter. To implement this work, it has been validated the technical feasibility, developed a methodology to automate each production phase: hydrological terrain models generation with 2 meter grid size and river network extraction combining hydrographic criteria (topographic network) and hydrological criteria (flow accumulation river network), and finally the production was launched. The key points of this work has been managing a big data environment, more than 160,000 Lidar data files, the infrastructure to store (up to 40 Tb between results and intermediate files), and process; using local virtualization and the Amazon Web Service (AWS), which allowed to obtain this automatic production within 6 months, it also has been important the software stability (TerraScan-TerraSolid, GlobalMapper-Blue Marble , FME-Safe, ArcGIS-Esri) and finally, the human resources managing. The results of this production has been an accurate automatic river network extraction for the whole country with a significant improvement for the altimetric component of the 3D linear vector. This article presents the technical feasibility, the production methodology, the automatic river network extraction production and its advantages over traditional vector extraction systems.

  14. Leg automaticity is stronger than arm automaticity during simultaneous arm and leg cycling.

    PubMed

    Sakamoto, Masanori; Tazoe, Toshiki; Nakajima, Tsuyoshi; Endoh, Takashi; Komiyama, Tomoyoshi

    2014-04-01

    Recent studies indicate that human locomotion is quadrupedal in nature. An automatic rhythm-generating system is thought to play a crucial role in controlling arm and leg movements. In the present study, we attempted to elucidate differences between intrinsic arm and leg automaticity by investigating cadence variability during simultaneous arm and leg (AL) cycling. Participants performed AL cycling with visual feedback of arm or leg cadence. Participants were asked to focus their attention to match the predetermined cadence; this affects the automaticity of the rhythm-generating system. Leg cadence variability was only mildly affected when the participants intended to precisely adjust either their arm or leg cycling cadence to a predetermined value. In contrast, arm cadence variability significantly increased when the participants adjusted their leg cycling cadence to a predetermined value. These findings suggest that different neural mechanisms underlie the automaticities of arm and leg cycling and that the latter is stronger than the former during AL cycling.

  15. PN acquisition demodulator achieves automatic synchronization of a telemetry channel

    NASA Technical Reports Server (NTRS)

    Couvillon, L.

    1966-01-01

    Data demodulator for automatic sync acquisition provides an automatic means for obtaining initial word and bit synchronization in a pulse-code-modulated/phase-shift-keyed digital communications system.

  16. Using automatic programming for simulating reliability network models

    NASA Technical Reports Server (NTRS)

    Tseng, Fan T.; Schroer, Bernard J.; Zhang, S. X.; Wolfsberger, John W.

    1988-01-01

    This paper presents the development of an automatic programming system for assisting modelers of reliability networks to define problems and then automatically generate the corresponding code in the target simulation language GPSS/PC.

  17. 2. FRONT VIEW, TWO DOUBLE AUTOMATIC BLOCK SIGNALS, EASTBOUND ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. FRONT VIEW, TWO DOUBLE AUTOMATIC BLOCK SIGNALS, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  18. 4. OBLIQUE VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. OBLIQUE VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  19. 1. FRONT VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. FRONT VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  20. 3. REAR VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. REAR VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  1. 5 CFR 831.502 - Automatic separation; exemption.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Automatic separation; exemption. 831.502... REGULATIONS (CONTINUED) RETIREMENT Eligibility for Retirement § 831.502 Automatic separation; exemption. (a... automatic separation at the end of that month. The department or agency shall notify the employee of...

  2. 5 CFR 831.502 - Automatic separation; exemption.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Automatic separation; exemption. 831.502... REGULATIONS (CONTINUED) RETIREMENT Eligibility for Retirement § 831.502 Automatic separation; exemption. (a... automatic separation at the end of that month. The department or agency shall notify the employee of...

  3. 5 CFR 831.502 - Automatic separation; exemption.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Automatic separation; exemption. 831.502... REGULATIONS (CONTINUED) RETIREMENT Eligibility for Retirement § 831.502 Automatic separation; exemption. (a... automatic separation at the end of that month. The department or agency shall notify the employee of...

  4. 5 CFR 831.502 - Automatic separation; exemption.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Automatic separation; exemption. 831.502... REGULATIONS (CONTINUED) RETIREMENT Eligibility for Retirement § 831.502 Automatic separation; exemption. (a... automatic separation at the end of that month. The department or agency shall notify the employee of...

  5. 46 CFR 171.118 - Automatic ventilators and side ports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Automatic ventilators and side ports. 171.118 Section... Bulkhead or Weather Deck § 171.118 Automatic ventilators and side ports. (a) An automatic ventilator must... Officer, Marine Safety Center. (b) The design and construction of each gangway, cargo and coaling...

  6. 46 CFR 171.118 - Automatic ventilators and side ports.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Automatic ventilators and side ports. 171.118 Section... Bulkhead or Weather Deck § 171.118 Automatic ventilators and side ports. (a) An automatic ventilator must... Officer, Marine Safety Center. (b) The design and construction of each gangway, cargo and coaling...

  7. 46 CFR 153.980 - Isolation of automatic closing valves.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Isolation of automatic closing valves. 153.980 Section... Transfer Procedures § 153.980 Isolation of automatic closing valves. The person in charge of cargo transfer may isolate automatic closing valves described in § 153.408(b) from a cargo containment system if...

  8. 46 CFR 153.980 - Isolation of automatic closing valves.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Isolation of automatic closing valves. 153.980 Section... Transfer Procedures § 153.980 Isolation of automatic closing valves. The person in charge of cargo transfer may isolate automatic closing valves described in § 153.408(b) from a cargo containment system if...

  9. 49 CFR 236.826 - System, automatic train stop.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false System, automatic train stop. 236.826 Section 236... § 236.826 System, automatic train stop. A system so arranged that its operation will automatically result in the application of the brakes until the train has been brought to a stop....

  10. 49 CFR 236.826 - System, automatic train stop.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false System, automatic train stop. 236.826 Section 236... § 236.826 System, automatic train stop. A system so arranged that its operation will automatically result in the application of the brakes until the train has been brought to a stop....

  11. 49 CFR 236.826 - System, automatic train stop.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false System, automatic train stop. 236.826 Section 236... § 236.826 System, automatic train stop. A system so arranged that its operation will automatically result in the application of the brakes until the train has been brought to a stop....

  12. 49 CFR 236.826 - System, automatic train stop.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false System, automatic train stop. 236.826 Section 236... § 236.826 System, automatic train stop. A system so arranged that its operation will automatically result in the application of the brakes until the train has been brought to a stop....

  13. 49 CFR 236.826 - System, automatic train stop.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false System, automatic train stop. 236.826 Section 236... § 236.826 System, automatic train stop. A system so arranged that its operation will automatically result in the application of the brakes until the train has been brought to a stop....

  14. Automaticity of walking: functional significance, mechanisms, measurement and rehabilitation strategies

    PubMed Central

    Clark, David J.

    2015-01-01

    Automaticity is a hallmark feature of walking in adults who are healthy and well-functioning. In the context of walking, “automaticity” refers to the ability of the nervous system to successfully control typical steady state walking with minimal use of attention-demanding executive control resources. Converging lines of evidence indicate that walking deficits and disorders are characterized in part by a shift in the locomotor control strategy from healthy automaticity to compensatory executive control. This is potentially detrimental to walking performance, as an executive control strategy is not optimized for locomotor control. Furthermore, it places excessive demands on a limited pool of executive reserves. The result is compromised ability to perform basic and complex walking tasks and heightened risk for adverse mobility outcomes including falls. Strategies for rehabilitation of automaticity are not well defined, which is due to both a lack of systematic research into the causes of impaired automaticity and to a lack of robust neurophysiological assessments by which to gauge automaticity. These gaps in knowledge are concerning given the serious functional implications of compromised automaticity. Therefore, the objective of this article is to advance the science of automaticity of walking by consolidating evidence and identifying gaps in knowledge regarding: (a) functional significance of automaticity; (b) neurophysiology of automaticity; (c) measurement of automaticity; (d) mechanistic factors that compromise automaticity; and (e) strategies for rehabilitation of automaticity. PMID:25999838

  15. 14 CFR 29.1329 - Automatic pilot system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Automatic pilot system. 29.1329 Section 29... pilot system. (a) Each automatic pilot system must be designed so that the automatic pilot can— (1) Be sufficiently overpowered by one pilot to allow control of the rotorcraft; and (2) Be readily and...

  16. 14 CFR 27.1329 - Automatic pilot system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Automatic pilot system. 27.1329 Section 27... pilot system. (a) Each automatic pilot system must be designed so that the automatic pilot can— (1) Be sufficiently overpowered by one pilot to allow control of the rotorcraft; and (2) Be readily and...

  17. 14 CFR 171.263 - Localizer automatic monitor system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Localizer automatic monitor system. 171.263... System (ISMLS) § 171.263 Localizer automatic monitor system. (a) The ISMLS localizer equipment must provide an automatic monitor system that transmits a warning to designated local and remote control...

  18. 21 CFR 211.68 - Automatic, mechanical, and electronic equipment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Automatic, mechanical, and electronic equipment. 211.68 Section 211.68 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Equipment § 211.68 Automatic, mechanical, and electronic equipment. (a) Automatic, mechanical, or...

  19. 21 CFR 211.68 - Automatic, mechanical, and electronic equipment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Automatic, mechanical, and electronic equipment. 211.68 Section 211.68 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Equipment § 211.68 Automatic, mechanical, and electronic equipment. (a) Automatic, mechanical, or...

  20. 21 CFR 211.68 - Automatic, mechanical, and electronic equipment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Automatic, mechanical, and electronic equipment. 211.68 Section 211.68 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Equipment § 211.68 Automatic, mechanical, and electronic equipment. (a) Automatic, mechanical, or...

  1. 21 CFR 211.68 - Automatic, mechanical, and electronic equipment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Automatic, mechanical, and electronic equipment. 211.68 Section 211.68 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Equipment § 211.68 Automatic, mechanical, and electronic equipment. (a) Automatic, mechanical, or...

  2. 21 CFR 211.68 - Automatic, mechanical, and electronic equipment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Automatic, mechanical, and electronic equipment. 211.68 Section 211.68 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Equipment § 211.68 Automatic, mechanical, and electronic equipment. (a) Automatic, mechanical, or...

  3. 40 CFR 1037.660 - Automatic engine shutdown systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Automatic engine shutdown systems... § 1037.660 Automatic engine shutdown systems. This section specifies requirements that apply for certified automatic engine shutdown systems (AES) that are modeled under § 1037.520. It does not apply...

  4. 40 CFR 1037.660 - Automatic engine shutdown systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Automatic engine shutdown systems... § 1037.660 Automatic engine shutdown systems. This section specifies requirements that apply for certified automatic engine shutdown (AES) systems modeled under § 1037.520. It does not apply for...

  5. 14 CFR 27.1329 - Automatic pilot system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Automatic pilot system. 27.1329 Section 27... pilot system. (a) Each automatic pilot system must be designed so that the automatic pilot can— (1) Be sufficiently overpowered by one pilot to allow control of the rotorcraft; and (2) Be readily and...

  6. 14 CFR 29.1329 - Automatic pilot system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Automatic pilot system. 29.1329 Section 29... pilot system. (a) Each automatic pilot system must be designed so that the automatic pilot can— (1) Be sufficiently overpowered by one pilot to allow control of the rotorcraft; and (2) Be readily and...

  7. 30 CFR 77.314 - Automatic temperature control instruments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic temperature control instruments. 77... UNDERGROUND COAL MINES Thermal Dryers § 77.314 Automatic temperature control instruments. (a) Automatic temperature control instruments for thermal dryer system shall be of the recording type. (b)...

  8. 30 CFR 77.314 - Automatic temperature control instruments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic temperature control instruments. 77... UNDERGROUND COAL MINES Thermal Dryers § 77.314 Automatic temperature control instruments. (a) Automatic temperature control instruments for thermal dryer system shall be of the recording type. (b)...

  9. 30 CFR 77.314 - Automatic temperature control instruments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic temperature control instruments. 77... UNDERGROUND COAL MINES Thermal Dryers § 77.314 Automatic temperature control instruments. (a) Automatic temperature control instruments for thermal dryer system shall be of the recording type. (b)...

  10. 30 CFR 77.314 - Automatic temperature control instruments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic temperature control instruments. 77... UNDERGROUND COAL MINES Thermal Dryers § 77.314 Automatic temperature control instruments. (a) Automatic temperature control instruments for thermal dryer system shall be of the recording type. (b)...

  11. 30 CFR 77.314 - Automatic temperature control instruments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic temperature control instruments. 77... UNDERGROUND COAL MINES Thermal Dryers § 77.314 Automatic temperature control instruments. (a) Automatic temperature control instruments for thermal dryer system shall be of the recording type. (b)...

  12. 12 CFR 7.1018 - Automatic payment plan account.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Automatic payment plan account. 7.1018 Section... OPERATIONS Bank Powers § 7.1018 Automatic payment plan account. A national bank may, for the benefit and convenience of its savings depositors, adopt an automatic payment plan under which a savings account will...

  13. 30 CFR 75.1403-4 - Criteria-Automatic elevators.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Criteria-Automatic elevators. 75.1403-4 Section... Criteria—Automatic elevators. (a) The doors of automatic elevators should be equipped with interlocking switches so arranged that the elevator car will be immovable while any door is opened or unlocked,...

  14. 30 CFR 75.1403-4 - Criteria-Automatic elevators.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Criteria-Automatic elevators. 75.1403-4 Section... Criteria—Automatic elevators. (a) The doors of automatic elevators should be equipped with interlocking switches so arranged that the elevator car will be immovable while any door is opened or unlocked,...

  15. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic controls and brakes. 77.1401 Section... MINES Personnel Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  16. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic controls and brakes. 77.1401 Section... MINES Personnel Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  17. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic controls and brakes. 77.1401 Section... MINES Personnel Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  18. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic controls and brakes. 77.1401 Section... MINES Personnel Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  19. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic controls and brakes. 77.1401 Section... MINES Personnel Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  20. 46 CFR 15.816 - Automatic radar plotting aids (ARPAs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Automatic radar plotting aids (ARPAs). 15.816 Section 15... REQUIREMENTS Computations § 15.816 Automatic radar plotting aids (ARPAs). Every person in the required complement of deck officers, including the master, on seagoing vessels equipped with automatic radar...

  1. Flight Investigation of an Automatic Throttle Control in Landing Approaches

    NASA Technical Reports Server (NTRS)

    Lina, Lindsay J.; Champine, Robert A.; Morris, Garland J.

    1959-01-01

    A flight investigation of an automatic throttle control in landing approaches has been made. It was found that airspeed could be maintained satisfactorily by the automatic throttle control. Turbulent air caused undesirably large variations of engine power which were uncomfortable and disconcerting; nevertheless, the pilot felt that he could make approaches 5 knots slower with equal assurance when the automatic control was in operation.

  2. Automatic TLI recognition system, user`s guide

    SciTech Connect

    Lassahn, G.D.

    1997-02-01

    This report describes how to use an automatic target recognition system (version 14). In separate volumes are a general description of the ATR system, Automatic TLI Recognition System, General Description, and a programmer`s manual, Automatic TLI Recognition System, Programmer`s Guide.

  3. 21 CFR 892.1900 - Automatic radiographic film processor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automatic radiographic film processor. 892.1900... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1900 Automatic radiographic film processor. (a) Identification. An automatic radiographic film processor is a device intended to be used...

  4. 30 CFR 56.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  5. 21 CFR 892.1900 - Automatic radiographic film processor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automatic radiographic film processor. 892.1900... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1900 Automatic radiographic film processor. (a) Identification. An automatic radiographic film processor is a device intended to be used...

  6. Automatic Evaluations in Clinically Anxious and Nonanxious Children and Adolescents

    ERIC Educational Resources Information Center

    Vervoort, Leentje; Wolters, Lidewij H.; Hogendoorn, Sanne M.; Prins, Pier J. M.; de Haan, Else; Nauta, Maaike H.; Boer, Frits

    2010-01-01

    Automatic evaluations of clinically anxious and nonanxious children (n = 40, aged 8-16, 18 girls) were compared using a pictorial performance-based measure of automatic affective associations. Results showed a threat-related evaluation bias in clinically anxious but not in nonanxious children. In anxious participants, automatic evaluations of…

  7. Free energetics of rigid body association of ubiquitin binding domains: a biochemical model for binding mediated by hydrophobic interaction.

    PubMed

    Cui, Di; Ou, Shuching; Patel, Sandeep

    2014-07-01

    Weak intermolecular interactions, such as hydrophobic associations, underlie numerous biomolecular recognition processes. Ubiquitin is a small protein that represents a biochemical model for exploring thermodynamic signatures of hydrophobic association as it is widely held that a major component of ubiquitin's binding to numerous partners is mediated by hydrophobic regions on both partners. Here, we use atomistic molecular dynamics simulations in conjunction with the Adaptive Biasing Force sampling method to compute potentials of mean force (the reversible work, or free energy, associated with the binding process) to investigate the thermodynamic signature of complexation in this well-studied biochemical model of hydrophobic association. We observe that much like in the case of a purely hydrophobic solute (i.e., graphene, carbon nanotubes), association is favored by entropic contributions from release of water from the interprotein regions. Moreover, association is disfavored by loss of enthalpic interactions, but unlike in the case of purely hydrophobic solutes, in this case protein-water interactions are lost and not compensated for by additional water-water interactions generated upon release of interprotein and moreso, hydration, water. We further find that relative orientations of the proteins that mutually present hydrophobic regions of each protein to its partner are favored over those that do not. In fact, the free energy minimum as predicted by a force field based method recapitulates the experimental NMR solution structure of the complex.

  8. Analysis of the data from a distributed set of accelerometers, for reconstruction of set geometry and its rigid body motion

    SciTech Connect

    Vreeburg, J. P. B.

    1999-01-22

    The paper reports on a current line of research in accelerometry. Two subjects are addressed: the reconstruction of the location and attitude of a linear, or uni-axial, accelerometer from its output under a known motion, and the reconstruction of the acceleration field constituent vectors from the combined output of a known arrangement of linear accelerometers. The arrangement can be arbitrary and, consequently, does not require precision mounting. The component of the acceleration along the sensitive direction gives the ideal output of the accelerometer. When the motion that induces the acceleration is known, a set of five ideal measurement data may suffice to recover the location and attitude of the accelerometer. The formulas for this calculation are given. Their use is illustrated by simulation of an accelerometer and its output. The effects of errors are shown; noisy data are much less detrimental to the reconstruction calculations than systematic errors in the known motion. If the geometry of a set of accelerometers is known, their output can be combined for the reconstruction of the linear and angular motion components that induce the acceleration. Conventionally this is achieved by elimination of the contribution of the angular rate of the geometry to the acceleration field. Only special arrangements of accelerometers, discussed in the literature, allow elimination by elementary operations. A method, thought to be new, is presented for the elimination of the linear and angular acceleration contributions to the field sensed by an arbitrary arrangement of accelerometers, and the consequent recovery of the angular rate vector from the reduced data set. Particular difficulties are encountered in this process but it has been shown that successful reconstruction is possible when a redundant set of data is available. Various options are suggested for further analysis, with the goal to determine the minimum arrangement, identify system errors or improve data accuracy.

  9. BCL::EM-Fit: rigid body fitting of atomic structures into density maps using geometric hashing and real space refinement.

    PubMed

    Woetzel, Nils; Lindert, Steffen; Stewart, Phoebe L; Meiler, Jens

    2011-09-01

    Cryo-electron microscopy (cryoEM) can visualize large macromolecular assemblies at resolutions often below 10Å and recently as good as 3.8-4.5 Å. These density maps provide important insights into the biological functioning of molecular machineries such as viruses or the ribosome, in particular if atomic-resolution crystal structures or models of individual components of the assembly can be placed into the density map. The present work introduces a novel algorithm termed BCL::EM-Fit that accurately fits atomic-detail structural models into medium resolution density maps. In an initial step, a "geometric hashing" algorithm provides a short list of likely placements. In a follow up Monte Carlo/Metropolis refinement step, the initial placements are optimized by their cross correlation coefficient. The resolution of density maps for a reliable fit was determined to be 10 Å or better using tests with simulated density maps. The algorithm was applied to fitting of capsid proteins into an experimental cryoEM density map of human adenovirus at a resolution of 6.8 and 9.0 Å, and fitting of the GroEL protein at 5.4 Å. In the process, the handedness of the cryoEM density map was unambiguously identified. The BCL::EM-Fit algorithm offers an alternative to the established Fourier/Real space fitting programs. BCL::EM-Fit is free for academic use and available from a web server or as downloadable binary file at http://www.meilerlab.org.

  10. Time-Stepping Approximation of Rigid-Body Dynamics with Perfect Unilateral Constraints. I: The Inelastic Impact Case

    NASA Astrophysics Data System (ADS)

    Paoli, L.

    2010-11-01

    We consider a discrete mechanical system with a non-trivial mass matrix, subjected to perfect unilateral constraints described by the geometrical inequalities {f_{α} (q) ≥q 0, α in \\{1, dots, ν\\} (ν ≥q 1)}. We assume that the transmission of the velocities at impact is governed by Newton’s Law with a coefficient of restitution e = 0 (so that the impact is inelastic). We propose a time-discretization of the second order differential inclusion describing the dynamics, which generalizes the scheme proposed in Paoli (J Differ Equ 211:247-281, 2005) and, for any admissible data, we prove the convergence of approximate motions to a solution of the initial-value problem.

  11. BCL::EM-Fit: Rigid body fitting of atomic structures into density maps using geometric hashing and real space refinement

    PubMed Central

    Woetzel, Nils; Lindert, Steffen; Stewart, Phoebe L.; Meiler, Jens

    2011-01-01

    Cryo-Electron Microscopy can visualize large macromolecular assemblies at resolutions often below 10 Å and recently as good as 3.8–4.5 Å. These density maps provide important insights into the biological functioning of molecular machineries such as viruses or the ribosome, in particular if atomic-resolution crystal structures or models of individual components of the assembly can be placed into the density map. The present work introduces a novel algorithm termed BCL::EM-Fit that accurately fits atomic-detail structural models into medium resolution density maps. In an initial step, a “geometric hashing” algorithm provides a short list of likely placements. In a follow up Monte Carlo/Metropolis refinement step, the initial placements are optimized by their cross correlation coefficient. The resolution of density maps for a reliable fit was determined to be 10 Å or better using tests with simulated density maps. The algorithm was applied to fitting of capsid proteins into an experimental cryoEM density map of human adenovirus at a resolution of 6.8 and 9.0 Å, and fitting of the GroEL protein at 5.4 Å. In the process, the handedness of the cryoEM density map was unambiguously identified. The BCL::EM-Fit algorithm offers an alternative to the established Fourier/Real space fitting programs. BCL::EM-Fit is free for academic use and available from a webserver or as downloadable binary file at http://www.meilerlab.org. PMID:21565271

  12. Modelling multi-protein complexes using PELDOR distance measurements for rigid body minimisation experiments using XPLOR-NIH

    PubMed Central

    Hammond, Colin M.; Owen-Hughes, Tom; Norman, David G.

    2014-01-01

    Crystallographic and NMR approaches have provided a wealth of structural information about protein domains. However, often these domains are found as components of larger multi domain polypeptides or complexes. Orienting domains within such contexts can provide powerful new insight into their function. The combination of site specific spin labelling and Pulsed Electron Double Resonance (PELDOR) provide a means of obtaining structural measurements that can be used to generate models describing how such domains are oriented. Here we describe a pipeline for modelling the location of thio-reactive nitroxyl spin locations to engineered sties on the histone chaperone Vps75. We then use a combination of experimentally determined measurements and symmetry constraints to model the orientation in which homodimers of Vps75 associate to form homotetramers using the XPLOR-NIH platform. This provides a working example of how PELDOR measurements can be used to generate a structural model. PMID:25448300

  13. Automatic recognition of malicious intent indicators.

    SciTech Connect

    Drescher, D. J.; Yee, Mark L.; Giron, Casey; Fogler, Robert Joseph; Nguyen, Hung D.; Koch, Mark William

    2010-09-01

    A major goal of next-generation physical protection systems is to extend defenses far beyond the usual outer-perimeter-fence boundaries surrounding protected facilities. Mitigation of nuisance alarms is among the highest priorities. A solution to this problem is to create a robust capability to Automatically Recognize Malicious Indicators of intruders. In extended defense applications, it is not enough to distinguish humans from all other potential alarm sources as human activity can be a common occurrence outside perimeter boundaries. Our approach is unique in that it employs a stimulus to determine a malicious intent indicator for the intruder. The intruder's response to the stimulus can be used in an automatic reasoning system to decide the intruder's intent.

  14. Autotract: automatic cleaning and tracking of fibers

    NASA Astrophysics Data System (ADS)

    Prieto, Juan C.; Yang, Jean Y.; Budin, François; Styner, Martin

    2016-03-01

    We propose a new tool named Autotract to automate fiber tracking in diffusion tensor imaging (DTI). Autotract uses prior knowledge from a source DTI and a set of corresponding fiber bundles to extract new fibers for a target DTI. Autotract starts by aligning both DTIs and uses the source fibers as seed points to initialize a tractography algorithm. We enforce similarity between the propagated source fibers and automatically traced fibers by computing metrics such as fiber length and fiber distance between the bundles. By analyzing these metrics, individual fiber tracts can be pruned. As a result, we show that both bundles have similar characteristics. Additionally, we compare the automatically traced fibers against bundles previously generated and validated in the target DTI by an expert. This work is motivated by medical applications in which known bundles of fiber tracts in the human brain need to be analyzed for multiple datasets.

  15. Automatic digital-analog impedance plethysmograph

    NASA Astrophysics Data System (ADS)

    Goy, C. B.; Mauro, K. A.; Yanicelli, L. M.; Parodi, N. F.; Gómez López, M. A.; Herrera, M. C.

    2016-04-01

    Venous occlusion plethysmography (VOP) is a traditional method widely used to assess limb blood circulation. One common mode to record VOP is by means of evaluating limb volume changes using impedance plethysmography (IP). In this paper the design and implementation of an automatic digital-analog impedance plethysmograph (ADAIP) for VOP is presented. The system is tested using precision resistances in order to calculate its repeatability. Then its global performance is assessed by means of VOP recordings on the upper and me lower limb of a healthy volunteer. The obtained repeatability was very high (95%), and the VOP recordings where the expected ones. It can be concluded that the whole system performs well and that it is suitable for automatic VOP recording.

  16. Automatic design and manufacture of robotic lifeforms

    NASA Astrophysics Data System (ADS)

    Lipson, Hod; Pollack, Jordan B.

    2000-08-01

    Biological life is in control of its own means of reproduction, which generally involves complex, autocatalysing chemical reactions. But this autonomy of design and manufacture has not yet been realized artificially. Robots are still laboriously designed and constructed by teams of human engineers, usually at considerable expense. Few robots are available because these costs must be absorbed through mass production, which is justified only for toys, weapons and industrial systems such as automatic teller machines. Here we report the results of a combined computational and experimental approach in which simple electromechanical systems are evolved through simulations from basic building blocks (bars, actuators and artificial neurons); the `fittest' machines (defined by their locomotive ability) are then fabricated robotically using rapid manufacturing technology. We thus achieve autonomy of design and construction using evolution in a `limited universe' physical simulation coupled to automatic fabrication.

  17. Method for automatically scramming a nuclear reactor

    DOEpatents

    Ougouag, Abderrafi M.; Schultz, Richard R.; Terry, William K.

    2005-12-27

    An automatically scramming nuclear reactor system. One embodiment comprises a core having a coolant inlet end and a coolant outlet end. A cooling system operatively associated with the core provides coolant to the coolant inlet end and removes heated coolant from the coolant outlet end, thus maintaining a pressure differential therebetween during a normal operating condition of the nuclear reactor system. A guide tube is positioned within the core with a first end of the guide tube in fluid communication with the coolant inlet end of the core, and a second end of the guide tube in fluid communication with the coolant outlet end of the core. A control element is positioned within the guide tube and is movable therein between upper and lower positions, and automatically falls under the action of gravity to the lower position when the pressure differential drops below a safe pressure differential.

  18. Automatic line generalization using zero-crossings

    NASA Technical Reports Server (NTRS)

    Thapa, K.

    1988-01-01

    The problem of automating the process of line generalization has been very difficult. It has not been solved yet despite the concerted effort of many private firms as well as government agencies. There does not exist an algorithm which can automatically perform this process when there is a drastic change in scale between the original and generalized maps. In this paper, an algorithm which is successful in automatically generalizing lines from any large scale to any small scale is presented. The algorthm achieves different levels of smoothing the line while preserving the overall shape of the line. The results are compared with those obtained by manual methods. It was found that the results obtained by the algorithm are very close to those obtained by cartographers using manual methods.

  19. Automatic Prosodic Analysis to Identify Mild Dementia.

    PubMed

    Gonzalez-Moreira, Eduardo; Torres-Boza, Diana; Kairuz, Héctor Arturo; Ferrer, Carlos; Garcia-Zamora, Marlene; Espinoza-Cuadros, Fernando; Hernandez-Gómez, Luis Alfonso

    2015-01-01

    This paper describes an exploratory technique to identify mild dementia by assessing the degree of speech deficits. A total of twenty participants were used for this experiment, ten patients with a diagnosis of mild dementia and ten participants like healthy control. The audio session for each subject was recorded following a methodology developed for the present study. Prosodic features in patients with mild dementia and healthy elderly controls were measured using automatic prosodic analysis on a reading task. A novel method was carried out to gather twelve prosodic features over speech samples. The best classification rate achieved was of 85% accuracy using four prosodic features. The results attained show that the proposed computational speech analysis offers a viable alternative for automatic identification of dementia features in elderly adults. PMID:26558287

  20. Automatic document navigation for digital content remastering

    NASA Astrophysics Data System (ADS)

    Lin, Xiaofan; Simske, Steven J.

    2003-12-01

    This paper presents a novel method of automatically adding navigation capabilities to re-mastered electronic books. We first analyze the need for a generic and robust system to automatically construct navigation links into re-mastered books. We then introduce the core algorithm based on text matching for building the links. The proposed method utilizes the tree-structured dictionary and directional graph of the table of contents to efficiently conduct the text matching. Information fusion further increases the robustness of the algorithm. The experimental results on the MIT Press digital library project are discussed and the key functional features of the system are illustrated. We have also investigated how the quality of the OCR engine affects the linking algorithm. In addition, the analogy between this work and Web link mining has been pointed out.