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Sample records for rational plane curves

  1. Craniofacial Reconstruction Using Rational Cubic Ball Curves

    PubMed Central

    Majeed, Abdul; Mt Piah, Abd Rahni; Gobithaasan, R. U.; Yahya, Zainor Ridzuan

    2015-01-01

    This paper proposes the reconstruction of craniofacial fracture using rational cubic Ball curve. The idea of choosing Ball curve is based on its robustness of computing efficiency over Bezier curve. The main steps are conversion of Digital Imaging and Communications in Medicine (Dicom) images to binary images, boundary extraction and corner point detection, Ball curve fitting with genetic algorithm and final solution conversion to Dicom format. The last section illustrates a real case of craniofacial reconstruction using the proposed method which clearly indicates the applicability of this method. A Graphical User Interface (GUI) has also been developed for practical application. PMID:25880632

  2. Craniofacial reconstruction using rational cubic ball curves.

    PubMed

    Majeed, Abdul; Mt Piah, Abd Rahni; Gobithaasan, R U; Yahya, Zainor Ridzuan

    2015-01-01

    This paper proposes the reconstruction of craniofacial fracture using rational cubic Ball curve. The idea of choosing Ball curve is based on its robustness of computing efficiency over Bezier curve. The main steps are conversion of Digital Imaging and Communications in Medicine (Dicom) images to binary images, boundary extraction and corner point detection, Ball curve fitting with genetic algorithm and final solution conversion to Dicom format. The last section illustrates a real case of craniofacial reconstruction using the proposed method which clearly indicates the applicability of this method. A Graphical User Interface (GUI) has also been developed for practical application. PMID:25880632

  3. Finding Rational Parametric Curves of Relative Degree One or Two

    ERIC Educational Resources Information Center

    Boyles, Dave

    2010-01-01

    A plane algebraic curve, the complete set of solutions to a polynomial equation: f(x, y) = 0, can in many cases be drawn using parametric equations: x = x(t), y = y(t). Using algebra, attempting to parametrize by means of rational functions of t, one discovers quickly that it is not the degree of f but the "relative degree," that describes how…

  4. Integrable mappings of the plane preserving biquadratic invariant curves II

    NASA Astrophysics Data System (ADS)

    Iatrou, Apostolos; Roberts, John A. G.

    2002-03-01

    We review recently introduced curve-dependent McMillan maps which are mappings of the plane that preserve biquadratic foliations. We show that they are measure preserving and thus integrable. We discuss the geometry of these maps including their fixed points and their stability. We consider the normal forms of symmetric and asymmetric biquadratic curves and the normal forms for their associated McMillan maps. We further discuss the dynamics on biquadratic curves by considering the possibility of parametrizing them by Jacobian elliptic or rational functions.

  5. Differentialless geometry of plane curves

    NASA Astrophysics Data System (ADS)

    Latecki, Longin J.; Rosenfeld, Azriel

    1997-10-01

    We introduce a class of planar arcs and curves, called tame arcs, which is general enough to describe the boundaries of planar real objects. A tame arc can have smooth parts as well as sharp corners; thus a polygonal arc is tame. On the other hand, this class of arcs is restrictive enough to rule out pathological arcs which have infinitely many inflections or which turn infinitely often: a tame arc can have only finitely many inflections, and its total absolute turn must be finite. In order to relate boundary properties of discrete objects obtained by segmenting digital images to the corresponding properties of their continuous originals, the theory of tame arcs is based on concepts that can be directly transferred from the continuous to the discrete domain. A tame arc is composed of a finite number of supported arcs. We define supported digital arcs and motivate their definition by the fact that hey can be obtained by digitizing continuous supported arcs. Every digital arc is tame, since it contains a finite number of points, and therefore it can be decomposed into a finite number of supported digital arcs.

  6. Solid-state curved focal plane arrays

    NASA Technical Reports Server (NTRS)

    Nikzad, Shouleh (Inventor); Hoenk, Michael (Inventor); Jones, Todd (Inventor)

    2010-01-01

    The present invention relates to curved focal plane arrays. More specifically, the present invention relates to a system and method for making solid-state curved focal plane arrays from standard and high-purity devices that may be matched to a given optical system. There are two ways to make a curved focal plane arrays starting with the fully fabricated device. One way, is to thin the device and conform it to a curvature. A second way, is to back-illuminate a thick device without making a thinned membrane. The thick device is a special class of devices; for example devices fabricated with high purity silicon. One surface of the device (the non VLSI fabricated surface, also referred to as the back surface) can be polished to form a curved surface.

  7. Microorganism billiards in closed plane curves

    NASA Astrophysics Data System (ADS)

    Krieger, Madison

    Recent experiments and numerical simulations have demonstrated that many species of microorganisms reflect aspecularly from a solid surface -- due to steric and hydrodynamic interactions with the wall, their outgoing angle is fixed and independent of the angle of incidence. Motivated by these results, we discuss theory and computation of the ``aspecular billiard'', a modification of the classical billiard in which the outgoing angle is constant. We restrict our attention to closed plane curves, focusing on three canonical examples: the ellipse, the Bunimovich stadium, and the Sinai billiard. These systems can have a rich array of orbits, and the Lyapunov exponent is shown to be dependent on the billiard geometry and the outgoing angle. We apply these results to the design of tunable passive sorting mechanisms.

  8. Renormalizations and Wandering Jordan Curves of Rational Maps

    NASA Astrophysics Data System (ADS)

    Cui, Guizhen; Peng, Wenjuan; Tan, Lei

    2016-05-01

    We realize a dynamical decomposition for a post-critically finite rational map which admits a combinatorial decomposition. We split the Riemann sphere into two completely invariant subsets. One is a subset of the Julia set consisting of uncountably many Jordan curve components. Most of them are wandering. The other consists of components that are pullbacks of finitely many renormalizations, together with possibly uncountably many points. The quotient action on the decomposed pieces is encoded by a dendrite dynamical system. We also introduce a surgery procedure to produce post-critically finite rational maps with wandering Jordan curves and prescribed renormalizations.

  9. Renormalizations and Wandering Jordan Curves of Rational Maps

    NASA Astrophysics Data System (ADS)

    Cui, Guizhen; Peng, Wenjuan; Tan, Lei

    2016-04-01

    We realize a dynamical decomposition for a post-critically finite rational map which admits a combinatorial decomposition. We split the Riemann sphere into two completely invariant subsets. One is a subset of the Julia set consisting of uncountably many Jordan curve components. Most of them are wandering. The other consists of components that are pullbacks of finitely many renormalizations, together with possibly uncountably many points. The quotient action on the decomposed pieces is encoded by a dendrite dynamical system. We also introduce a surgery procedure to produce post-critically finite rational maps with wandering Jordan curves and prescribed renormalizations.

  10. Curved-Focal-Plane Arrays Using Deformed-Membrane Photodetectors

    NASA Technical Reports Server (NTRS)

    Nikzad, Shouleh; Jones, Todd

    2004-01-01

    A versatile and simple approach to the design and fabrication of curved-focal-plane arrays of silicon-based photodetectors is being developed. This approach is an alternative to the one described in "Curved Focal-Plane Arrays Using Back- Illuminated High-Purity Photodetectors" (NPO-30566), NASA Tech Briefs, Vol. 27, No. 10 (October 2003), page 10a. As in the cited prior article, the basic idea is to improve the performance of an imaging instrument and simplify the optics needed to obtain a given level of performance by making an image sensor (in this case, an array of photodetectors) conform to a curved focal surface, instead of designing the optics to project an image onto a flat focal surface. There is biological precedent for curved-focal-surface designs: retinas - the image sensors in eyes - conform to the naturally curved focal surfaces of eye lenses. The present approach is applicable to both front-side- and back-side-illuminated, membrane photodetector arrays and is being demonstrated on charge-coupled devices (CCDs). The very-large scale integrated (VLSI) circuitry of such a CCD or other array is fabricated on the front side of a silicon substrate, then the CCD substrate is attached temporarily to a second substrate for mechanical support, then material is removed from the back to obtain the CCD membrane, which typically has a thickness between 10 and 20 m. In the case of a CCD designed to operate in back-surface illumination, delta doping can be performed after thinning to enhance the sensitivity. This approach is independent of the design and method of fabrication of the front-side VLSI circuitry and does not involve any processing of a curved silicon substrate. In this approach, a third substrate would be prepared by polishing one of its surfaces to a required focal-surface curvature. A CCD membrane fabricated as described above would be pressed against, deformed into conformity with, and bonded to, the curved surface. The technique used to press and

  11. A Curved, Elastostatic Boundary Element for Plane Anisotropic Structures

    NASA Technical Reports Server (NTRS)

    Smeltzer, Stanley S.; Klang, Eric C.

    2001-01-01

    The plane-stress equations of linear elasticity are used in conjunction with those of the boundary element method to develop a novel curved, quadratic boundary element applicable to structures composed of anisotropic materials in a state of plane stress or plane strain. The curved boundary element is developed to solve two-dimensional, elastostatic problems of arbitrary shape, connectivity, and material type. As a result of the anisotropy, complex variables are employed in the fundamental solution derivations for a concentrated unit-magnitude force in an infinite elastic anisotropic medium. Once known, the fundamental solutions are evaluated numerically by using the known displacement and traction boundary values in an integral formulation with Gaussian quadrature. All the integral equations of the boundary element method are evaluated using one of two methods: either regular Gaussian quadrature or a combination of regular and logarithmic Gaussian quadrature. The regular Gaussian quadrature is used to evaluate most of the integrals along the boundary, and the combined scheme is employed for integrals that are singular. Individual element contributions are assembled into the global matrices of the standard boundary element method, manipulated to form a system of linear equations, and the resulting system is solved. The interior displacements and stresses are found through a separate set of auxiliary equations that are derived using an Airy-type stress function in terms of complex variables. The capabilities and accuracy of this method are demonstrated for a laminated-composite plate with a central, elliptical cutout that is subjected to uniform tension along one of the straight edges of the plate. Comparison of the boundary element results for this problem with corresponding results from an analytical model show a difference of less than 1%.

  12. Interfacial Refraction Through Curved and Plane-Layered Media

    SciTech Connect

    Kehoe, A.B.

    2001-07-17

    Two laser beam tracing codes, AXIAL and CYLINDER, have been written to determine a laser beam path through plane and cylindrical interfaces. For cylindrical interfaces, an equation set was derived which describes the path of the laser beam. For plane interfaces, it was not possible to derive a single equation set. Instead, it was necessary to divide the domain up into small elements or regions. The laser beam path was then determined by calculating the path of the laser beam through each region. AXIAL and CYLINDER can be used to determine where an LDA should be positioned so that velocity measurements can be made at a specified point.

  13. A curve shortening flow rule for closed embedded plane curves with a prescribed rate of change in enclosed area

    PubMed Central

    Dallaston, Michael C.

    2016-01-01

    Motivated by a problem from fluid mechanics, we consider a generalization of the standard curve shortening flow problem for a closed embedded plane curve such that the area enclosed by the curve is forced to decrease at a prescribed rate. Using formal asymptotic and numerical techniques, we derive possible extinction shapes as the curve contracts to a point, dependent on the rate of decreasing area; we find there is a wider class of extinction shapes than for standard curve shortening, for which initially simple closed curves are always asymptotically circular. We also provide numerical evidence that self-intersection is possible for non-convex initial conditions, distinguishing between pinch-off and coalescence of the curve interior. PMID:26997898

  14. Performance characteristics of a curved-channel microchannel plate with a curved input face and a plane output face

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Morgan, Jeffrey S.; Timothy, J. Gethyn

    1989-01-01

    The presently performance-evaluated format, in which a high-gain curved-channel microchannel plate (M2MCP) has a spherical concave input face and a plane output face, allows the input face of the MCP (1) to match such curved focal surfaces as that of a Rowland-circle spectrometer mounting, while (2) having a high-resolution plane readout array in proximity focus with the output face. This MCP has been evaluated in a discrete-anode multicathode microchannel array detector system. The saturated modal gain was found to be inversely proportional to the length/diameter ratio of the channels and directly proportional to the applied MCP voltage.

  15. A study of a collision avoidance system mounted on a curved ground plane

    NASA Technical Reports Server (NTRS)

    Law, P. H.; Burnside, W. D.; Rojas, R. G.

    1986-01-01

    Research conducted on a traffic advisory and collision avoidance system (TCAS 2) mounted on a curved ground plane is described. It is found that a curved finite ground plane can be used as a good simulation model for the fuselage of an aircraft but may not be good enough to model a whole aircraft due to the shadowing of the vertical stabilizer, wings, etc. The surface curvature of this curved disc significantly affects the monopulse characteristics in the azimuth plane but not as much in the elevation plane. These variations of the monopulse characteristics verify the need of a lookup table for the 64 azimuth beam positions. The best location of a TCAS 2 array on a Boeing 737 is to move it as far from the vertical stabilizer as possible.

  16. Rationality.

    PubMed

    Sosis, Clifford; Bishop, Michael A

    2014-01-01

    A theory of rationality is a theory that evaluates instances of reasoning as rational, irrational, or (ir)rational to some degree. Theories can be categorized as rule-based or consequentialist. Rule-based theories say that rational reasoning accords with certain rules (e.g., of logic or probability). Consequentialist theories say that rational reasoning tends to produce good consequences. For instance, the reliabilist takes rationality to be reasoning that tends to produce mostly true beliefs. The pragmatist takes it to be reasoning that tends to produce mostly useful beliefs. This article reviews some of the features and the challenges of rule-based, reliabilist, and pragmatist theories of rationality. WIREs Cogn Sci 2014, 5:27-37. doi: 10.1002/wcs.1263 CONFLICT OF INTEREST: The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. PMID:26304295

  17. On the grid generation methods in harmonic mapping on plane and curved surfaces

    NASA Technical Reports Server (NTRS)

    Sritharan, S. S.; Smith, P. W.

    1984-01-01

    Harmonic grid generation methods for multiply connected plane regions and regions on curved surfaces are discussed. In particular, using a general formulation on an analytic Riemannian manifold, it is proved that these mappings are globally one-to-one and onto.

  18. Designing of skull defect implants using C1 rational cubic Bezier and offset curves

    NASA Astrophysics Data System (ADS)

    Mohamed, Najihah; Majid, Ahmad Abd; Piah, Abd Rahni Mt; Rajion, Zainul Ahmad

    2015-05-01

    Some of the reasons to construct skull implant are due to head trauma after an accident or an injury or an infection or because of tumor invasion or when autogenous bone is not suitable for replacement after a decompressive craniectomy (DC). The main objective of our study is to develop a simple method to redesign missing parts of the skull. The procedure begins with segmentation, data approximation, and estimation process of the outer wall by a C1 continuous curve. Its offset curve is used to generate the inner wall. A metaheuristic algorithm, called harmony search (HS) is a derivative-free real parameter optimization algorithm inspired from the musical improvisation process of searching for a perfect state of harmony. In this study, data approximation by a rational cubic Bézier function uses HS to optimize position of middle points and value of the weights. All the phases contribute significantly in making our proposed technique automated. Graphical examples of several postoperative skulls are displayed to show the effectiveness of our proposed method.

  19. The Definition and Computation of a Metric on Plane Curves. The Meaning of a Face on a Geometric Model

    NASA Technical Reports Server (NTRS)

    Emery, J. D.

    1985-01-01

    Two topics in topology, the comparison of plane curves and faces on geometric models, are discussed. With regard to the first problem, a curve is defined to be a locus of points without any underlying parameterization. A metric on a class of plane curves is defined, a finite computation of this metric is given for the case of piecewise linear curves, and it is shown how to approximate curves that have bounded curvature by piecewise linear curves. In this way a bound on the distance between two curves can be computed. With regard to the second problem, the questions to be discussed are under what circumstances do geometrical faces make sense; how can they be explicity defined; and when are these geometrical faces homeomorphic to the realization of the abstract (topological) face.

  20. In-plane vibration analysis of curved carbon nanotubes conveying fluid embedded in viscoelastic medium

    NASA Astrophysics Data System (ADS)

    Ghavanloo, Esmaeal; Rafiei, Masoud; Daneshmand, Farhang

    2011-05-01

    The effect of the induced vibrations in the carbon nanotubes (CNTs) arising from the internal fluid flow is a critical issue in the design of CNT-based fluidic devices. In this study, in-plane vibration analysis of curved CNTs conveying fluid embedded in viscoelastic medium is investigated. The CNT is modeled as a linear elastic cylindrical tube where the internal moving fluid is characterized by steady flow velocity and mass density of fluid. A modified-inextensible theory is used in formulation and the steady-state initial forces due to the centrifugal and pressure forces of the internal fluid are also taken into account. The finite element method is used to discretize the equation of motion and the frequencies are obtained by solving a quadratic eigenvalue problem. The effects of CNT opening angle, the elastic modulus and the damping factor of the viscoelastic surrounded medium and fluid velocity on the resonance frequencies are elucidated. It is shown that curved CNTs are unconditionally stable even for a system with sufficiently high flow velocity. The most results presented in this investigation have been absent from the literature for fluid-induced vibration of curved CNTs embedded in viscoelastic foundations.

  1. Hemispherical curved monolithic cooled and uncooled infrared focal plane arrays for compact cameras

    NASA Astrophysics Data System (ADS)

    Tekaya, Kevin; Fendler, Manuel; Dumas, Delphine; Inal, Karim; Massoni, Elisabeth; Gaeremynck, Yann; Druart, Guillaume; Henry, David

    2014-06-01

    InfraRed (IR) sensor systems like night vision goggles, missile approach warning systems and telescopes have an increasing interest in decreasing their size and weight. At the same time optical aberrations are always more difficult to optimize with larger Focal Plane Arrays (FPAs) and larger field of view. Both challenges can now take advantage of a new optical parameter thanks to flexible microelectronics technologies: the FPA spherical curvature. This bio-inspired approach can correct optical aberrations and reduce the number of lenses in camera conception. Firstly, a new process to curve thin monolithic devices has been applied to uncooled microbolometers FPAs. A functional 256×320 25μm pitch (roughly 1cm2) uncooled FPA has been thinned and curved. Its electrical response showed no degradation after our process (variation of less than 2.3% on the response). Then a two lenses camera with a curved FPA is designed and characterized in comparison with a two lenses camera with a flat FPA. Their Modulation Transfer Functions (MTFs) show clearly an improvement in terms of beams dispersion. Secondly, a new process to fabricate monolithic cooled flip-chip MCT-IRCMOS FPAs was developed leading to the first spherical cooled IR FPA: with a radius of 550 mm. Other radii are achieved. A standard opto-electrical characterization at 80 K of the imager shows no additional short circuit and no mean response alteration compared to a standard IRCMOS shown in reference. Noise is also studied with a black body between 20 and 30°C.

  2. A unified approach for nonlinear vibration analysis of curved structures using non-uniform rational B-spline representation

    NASA Astrophysics Data System (ADS)

    Askari, H.; Esmailzadeh, E.; Barari, A.

    2015-09-01

    A novel procedure for the nonlinear vibration analysis of curved beam is presented. The Non-Uniform Rational B-Spline (NURBS) is combined with the Euler-Bernoulli beam theory to define the curvature of the structure. The governing equation of motion and the general frequency formula, using the NURBS variables, is applicable for any type of curvatures, is developed. The Galerkin procedure is implemented to obtain the nonlinear ordinary differential equation of curved system and the multiple time scales method is utilized to find the corresponding frequency responses. As a case study, the nonlinear vibration of carbon nanotubes with different shapes of curvature is investigated. The effect of oscillation amplitude and the waviness on the natural frequency of the curved nanotube is evaluated and the primary resonance case of system with respect to the variations of different parameters is discussed. For the sake of comparison of the results obtained with those from the molecular dynamic simulation, the natural frequencies evaluated from the proposed approach are compared with those reported in literature for few types of carbon nanotube simulation.

  3. Dome Shape Optimization of Composite Pressure Vessels Based on Rational B-Spline Curve and Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Vafaeesefat, Abbas

    2009-10-01

    This paper presents an algorithm for shape optimization of composite pressure vessels head. The shape factor which is defined as the ratio of internal volume to weight of the vessel is used as an objective function. Design constrains consist of the geometrical limitations, winding conditions, and Tsai-Wu failure criterion. The geometry of dome shape is defined by a B-spline rational curve. By altering the weights of control points, depth of dome, and winding angle, the dome shape is changed. The proposed algorithm uses genetic algorithm and finite element analysis to optimize the design parameters. The algorithm is applied on a CNG pressure vessel and the results show that the proposed algorithm can efficiently define the optimal dome shape. This algorithm is general and can be used for general shape optimization.

  4. Rotational Analysis of Phase Plane Curves: Complex and Pure Imaginary Eigenvalues

    ERIC Educational Resources Information Center

    Murray, Russell H.

    2005-01-01

    Although the phase plane can be plotted and analyzed using an appropriate software package, the author found it worthwhile to engage the students with the theorem and the two proofs. The theorem is a powerful tool that provides insight into the rotational behavior of the phase plane diagram in a simple way: just check the signs of c and [alpha].…

  5. Development of cubic Bezier curve and curve-plane intersection method for parametric submarine hull form design to optimize hull resistance using CFD

    NASA Astrophysics Data System (ADS)

    Chrismianto, Deddy; Zakki, Ahmad Fauzan; Arswendo, Berlian; Kim, Dong Joon

    2015-12-01

    Optimization analysis and computational fluid dynamics (CFDs) have been applied simultaneously, in which a parametric model plays an important role in finding the optimal solution. However, it is difficult to create a parametric model for a complex shape with irregular curves, such as a submarine hull form. In this study, the cubic Bezier curve and curve-plane intersection method are used to generate a solid model of a parametric submarine hull form taking three input parameters into account: nose radius, tail radius, and length-height hull ratio ( L/ H). Application program interface (API) scripting is also used to write code in the ANSYS design modeler. The results show that the submarine shape can be generated with some variation of the input parameters. An example is given that shows how the proposed method can be applied successfully to a hull resistance optimization case. The parametric design of the middle submarine type was chosen to be modified. First, the original submarine model was analyzed, in advance, using CFD. Then, using the response surface graph, some candidate optimal designs with a minimum hull resistance coefficient were obtained. Further, the optimization method in goal-driven optimization (GDO) was implemented to find the submarine hull form with the minimum hull resistance coefficient ( C t ). The minimum C t was obtained. The calculated difference in C t values between the initial submarine and the optimum submarine is around 0.26%, with the C t of the initial submarine and the optimum submarine being 0.001 508 26 and 0.001 504 29, respectively. The results show that the optimum submarine hull form shows a higher nose radius ( r n ) and higher L/ H than those of the initial submarine shape, while the radius of the tail ( r t ) is smaller than that of the initial shape.

  6. Transverse plane of apical vertebra of structural thoracic curve: vertebra displacement versus vertebral deformation.

    PubMed

    Kotwicki, Tomasz; Napiontek, Marek; Nowakowski, Andrzej

    2006-01-01

    CT transversal scans of the trunk provided at the level of Th8 or Th9 (apical vertebra) of 23 patients with structural thoracic scoliosis were reviewed. The following parameters were studied: 1) alpha angle formed by the axis of vertebra and the axis of spinous process, 2) beta concave and beta convex angle between the spinous process and the left and right transverse process respectively, 3) gamma concave and gamma convex angle between the axis of vertebra and the left and right transverse process respectively, 4) rotation angle to the sagittal plane according to Aaro and Dahlborn, 5) Cobb angle. Values of measured parameters demonstrated a common pattern of intravertebral deformity: counter clockwise deviation of the spinous process (alpha angle 15,0 +/-8,5 degrees), beta concave (69,8 +/-8,5 degrees) significantly greater than beta convex (38,8 +/-8,5 degrees), gamma concave (54,3 +/-7,8 degrees) not different from gamma convex (56,0 +/-8,0 degrees). Strong linear positive correlation between alpha angle and Aaro-Dahlborn angle was observed (r=0,78, p<0,05). Changes in morphology of apical vertebra due to intravertebral bone remodelling followed the vertebral spatial displacement and there existed a linear correlation in between. The two processes develop in opposite directions. PMID:17108421

  7. Pre-curving analysis of an opening crack in a magnetoelectroelastic strip under in-plane impact loadings

    NASA Astrophysics Data System (ADS)

    Hu, Keqiang; Chen, Zengtao

    2012-12-01

    An opening crack in a magnetoelectroelastic strip under in-plane mechanical, electric, and magnetic impact loadings is considered for magneto-electrically impermeable and permeable crack surface boundary conditions. Laplace and Fourier transforms are applied to reduce the mixed boundary value problem of the crack to dual integral equations, which are expressed in terms of Fredholm integral equations of the second kind. The asymptotic fields near the crack tip are obtained in explicit form and the corresponding field intensity factors are defined. The crack curving phenomena are investigated by applying the criterion of maximum hoop stress intensity factors. Numerical results show that the hoop stress intensity factors are influenced by the electric and magnetic loadings and the geometric size ratios.

  8. Traveling Wave Solutions of the Gardner Equation and Motion of Plane Curves Governed by the mKdV Flow

    SciTech Connect

    Vassilev, V. M.; Djondjorov, P. A.; Hadzhilazova, M. Ts.; Mladenov, I. M.

    2011-11-29

    The Gardner equation is well-known in the mathematical literature since the late sixties of 20th century. Initially, it appeared in the context of the construction of local conservation laws admitted by the KdV equation. Later on, the Gardner equation was generalized and found to be applicable in various branches of physics (solid-state and plasma physics, fluid dynamics and quantum field theory). In this paper, we examine the travelling wave solutions of the Gardner equation and derive the full set of solutions to the corresponding reduced equation in terms of Weierstrass and Jacobi elliptic functions. Then, we use the travelling wave solutions of the focusing mKdV equation and obtain in explicit analytic form exact solutions of a special type of plane curve flow, known as the mKdV flow.

  9. On the cost of approximating and recognizing a noise perturbed straight line or a quadratic curve segment in the plane. [central processing units

    NASA Technical Reports Server (NTRS)

    Cooper, D. B.; Yalabik, N.

    1975-01-01

    Approximation of noisy data in the plane by straight lines or elliptic or single-branch hyperbolic curve segments arises in pattern recognition, data compaction, and other problems. The efficient search for and approximation of data by such curves were examined. Recursive least-squares linear curve-fitting was used, and ellipses and hyperbolas are parameterized as quadratic functions in x and y. The error minimized by the algorithm is interpreted, and central processing unit (CPU) times for estimating parameters for fitting straight lines and quadratic curves were determined and compared. CPU time for data search was also determined for the case of straight line fitting. Quadratic curve fitting is shown to require about six times as much CPU time as does straight line fitting, and curves relating CPU time and fitting error were determined for straight line fitting. Results are derived on early sequential determination of whether or not the underlying curve is a straight line.

  10. A Rational Expectations Experiment.

    ERIC Educational Resources Information Center

    Peterson, Norris A.

    1990-01-01

    Presents a simple classroom simulation of the Lucas supply curve mechanism with rational expectations. Concludes that the exercise has proved very useful as an introduction to the concepts of rational and adaptive expectations, the Lucas supply curve, the natural rate hypothesis, and random supply shocks. (DB)

  11. Electric Field Optimization in 170 kV Gas-Insulated Switchgear Spacer based on Non-Uniform Rational B-spline Curve

    NASA Astrophysics Data System (ADS)

    Han, In Su; Kim, Eung Sik; Min, Suk Won; Hur, Don; Park, Jong Keun

    2004-10-01

    In this paper, the electric field at the spacer in a 170 kV gas-insulated switchgear (GIS) is optimized. Initially, the tangential and total electric fields around the original shape of the 170 kV GIS produced by a Korean company are calculated using a combination of the charge simulation method (CSM) and surface charge method (SCM). The contour of the spacer in the 170 kV GIS is found using a non-uniform rational B-spline (NURB) curve the effectiveness of which has been proved. By moving some control points in the NURB curve, the initial shape of the 170 kV GIS can be determined so that we may begin to optimize the electric field. Owing to the proposed algorithm, the overall process has a stable convergence. The objects that we want to design are the upper and lower parts of the spacer. Finally, we can find the shapes in which the tangential and total electric fields are optimized.

  12. Surface Activation of Plane and Curved Automotive Polymer Surfaces by Using a Fittable Multi-Pin DBD Plasma Source

    NASA Astrophysics Data System (ADS)

    Jörn, Heine; Roland, Damm; Christoph, Gerhard; Stephan, Wieneke; Wolfgang, Viöl

    2014-06-01

    In this work, surface activation of automotive polymers using atmospheric pressure plasmas was investigated. The aim was to increase the polar fraction of the surface energy of both plane and convex polymer devices with a radius in the range of 30 mm. For this purpose, a fittable low temperature atmospheric pressure plasma source based on capacitively coupled multi-pin electrodes was set up and applied. Each single electrode generates a treatment spot of approximately 2 cm2 with a tunable power density of up to 1.4 W/cm2. The surface energy was evaluated by contact angle measurements. After treatment at a low energy density of 1.01 J/cm2, the polar fraction of the surface energy of the investigated polymers was increased by a factor of 3.3 to 132, depending on the polymer materials. It was shown that by applying the presented fittable plasma source, this effect is independent of the surface radius of the polymer sample.

  13. The computation of all plane/surface intersections for CAD/CAM applications

    NASA Technical Reports Server (NTRS)

    Hoitsma, D. H., Jr.; Roche, M.

    1984-01-01

    The problem of the computation and display of all intersections of a given plane with a rational bicubic surface patch for use on an interactive CAD/CAM system is examined. The general problem of calculating all intersections of a plane and a surface consisting of rational bicubic patches is reduced to the case of a single generic patch by applying a rejection algorithm which excludes all patches that do not intersect the plane. For each pertinent patch the algorithm presented computed the intersection curves by locating an initial point on each curve, and computes successive points on the curve using a tolerance step equation. A single cubic equation solver is used to compute the initial curve points lying on the boundary of a surface patch, and the method of resultants as applied to curve theory is used to determine critical points which, in turn, are used to locate initial points that lie on intersection curves which are in the interior of the patch. Examples are given to illustrate the ability of this algorithm to produce all intersection curves.

  14. Confucian Rationalism

    ERIC Educational Resources Information Center

    Lam, Chi-Ming

    2014-01-01

    Nowadays, there is still a widely held view that the Chinese and Western modes of thought are quite distinct from each other. In particular, the Chinese mode of thought derived from Confucianism is considered as comparatively less rational than the Western one. In this article, I first argue that although the analogical mode of argumentation,…

  15. Acoustic plane waves normally incident on a clamped panel in a rectangular duct. [to explain noise reduction curves for reducing interior noise in aircraft

    NASA Technical Reports Server (NTRS)

    Unz, H.; Roskam, J.

    1979-01-01

    The theory of acoustic plane wave normally incident on a clamped panel in a rectangular duct is developed. The coupling theory between the elastic vibrations of the panel (plate) and the acoustic wave propagation in infinite space and in the rectangular duct is considered. The partial differential equation which governs the vibration of the panel (plate) is modified by adding to its stiffness (spring) forces and damping forces, and the fundamental resonance frequency and the attenuation factor are discussed. The noise reduction expression based on the theory is found to agree well with the corresponding experimental data of a sample aluminum panel in the mass controlled region, the damping controlled region, and the stiffness controlled region. All the frequency positions of the upward and downward resonance spikes in the sample experimental data are identified theoretically as resulting from four cross interacting major resonance phenomena: the cavity resonance, the acoustic resonance, the plate resonance, and the wooden back panel resonance.

  16. An investigation of the diffraction of an acoustic plane wave by a curved surface of finite impedance. Ph.D. Thesis Final Technical Report, 1 Feb. 1985 - 1 Sep. 1989

    NASA Technical Reports Server (NTRS)

    Kearns, James A.

    1989-01-01

    Phenomena associated with long range propagation of sound over irregular topography motivated this work, which was to analyze the diffraction effects which would occur near the tops of hills and ridges. The diffraction of a high frequency plane wave due to its grazing of a two-dimensional curved surface of finite impedance was also studied. Laboratory scale models were constructed and measurements were made of the field on, above, and behind either of two curved surfaces possessing distinctly different impedances; that is, one was soft while the other was hard. The experimental technique consisted of simultaneously measuring the pressure at a reference point and at a field point due to a transient pulse generated by an electric spark. The pressure waveforms were digitized and processed. The ratio of the discrete Fourier transforms of the two waveforms provided an estimate of the insertion loss between them. The results of the measurements were compared with the predictions of a theory which was derived by Pierce using the method of Matched Asymptotic Expansions (MAE). The predictions relied upon the experimental evaluation of the impedance of each surface at grazing angles of incidence. This evaluation was achieved by a fairly standard technique involving empirical models of various generic types of surfaces. An example was shown of the important role that the structural intricacies of a surface play in the determination of an appropriate model. The comparison between the measurements and predictions indicated that the theory gives an excellent description of the field anywhere near a curved surface. Further, with a simple modification, the theory was also shown to give nearly as good of a description of the field surrounding a curved surface even at distances far behind the surface yet near the line of sight.

  17. Rationalization: A Bibliography.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    Rationalization was studied by Sigmund Freud and was specifically labeled by Ernest Jones. Rationalization ought to be differentiated from rational, rationality, logical analysis, etc. On the one hand, rationalization is considered a defense mechanism, on the other hand, rationality is not. Haan has done much work with self-report inventories and…

  18. RATIONAL SPLINE SUBROUTINES

    NASA Technical Reports Server (NTRS)

    Schiess, J. R.

    1994-01-01

    Scientific data often contains random errors that make plotting and curve-fitting difficult. The Rational-Spline Approximation with Automatic Tension Adjustment algorithm lead to a flexible, smooth representation of experimental data. The user sets the conditions for each consecutive pair of knots:(knots are user-defined divisions in the data set) to apply no tension; to apply fixed tension; or to determine tension with a tension adjustment algorithm. The user also selects the number of knots, the knot abscissas, and the allowed maximum deviations from line segments. The selection of these quantities depends on the actual data and on the requirements of a particular application. This program differs from the usual spline under tension in that it allows the user to specify different tension values between each adjacent pair of knots rather than a constant tension over the entire data range. The subroutines use an automatic adjustment scheme that varies the tension parameter for each interval until the maximum deviation of the spline from the line joining the knots is less than or equal to a user-specified amount. This procedure frees the user from the drudgery of adjusting individual tension parameters while still giving control over the local behavior of the spline The Rational Spline program was written completely in FORTRAN for implementation on a CYBER 850 operating under NOS. It has a central memory requirement of approximately 1500 words. The program was released in 1988.

  19. Birational maps that send biquadratic curves to biquadratic curves

    NASA Astrophysics Data System (ADS)

    Roberts, John A. G.; Jogia, Danesh

    2015-02-01

    Recently, many papers have begun to consider so-called non-Quispel-Roberts-Thompson (QRT) birational maps of the plane. Compared to the QRT family of maps which preserve each biquadratic curve in a fibration of the plane, non-QRT maps send a biquadratic curve to another biquadratic curve belonging to the same fibration or to a biquadratic curve from a different fibration of the plane. In this communication, we give the general form of a birational map derived from a difference equation that sends a biquadratic curve to another. The necessary and sufficient condition for such a map to exist is that the discriminants of the two biquadratic curves are the same (and hence so are the j-invariants). The result allows existing examples in the literature to be better understood and allows some statements to be made concerning their generality.

  20. [Constitutional requirements of rationing].

    PubMed

    Kluth, Winfried

    2008-01-01

    Rationing is an emotive issue in the field of public health. This complicates the rational discourse, which is indispensable for analyzing the rationing conditions as set out by constitutional law and which requires manifold differentiation and consideration that shall briefly be outlined in the following short contribution. Of central significance is the distinction between indirect and direct rationing as well as the reference to the essential responsibility of legislators for rationing decisions. PMID:19004184

  1. Graphing Polar Curves

    ERIC Educational Resources Information Center

    Lawes, Jonathan F.

    2013-01-01

    Graphing polar curves typically involves a combination of three traditional techniques, all of which can be time-consuming and tedious. However, an alternative method--graphing the polar function on a rectangular plane--simplifies graphing, increases student understanding of the polar coordinate system, and reinforces graphing techniques learned…

  2. Frequency curves

    USGS Publications Warehouse

    Riggs, H.C.

    1968-01-01

    This manual describes graphical and mathematical procedures for preparing frequency curves from samples of hydrologic data. It also discusses the theory of frequency curves, compares advantages of graphical and mathematical fitting, suggests methods of describing graphically defined frequency curves analytically, and emphasizes the correct interpretations of a frequency curve.

  3. Rationing medical education.

    PubMed

    Walsh, Kieran

    2016-03-01

    The purpose of this paper is to discuss the role of rationing in medical education. Medical education is expensive and there is a limit to that which governments, funders or individuals can spend on it. Rationing involves the allocation of resources that are limited. This paper discussed the pros and cons of the application of rationing to medical education and the different forms of rationing that could be applied. Even though some stakeholders in medical education might be taken aback at the prospect of rationing, the truth is that rationing has always occurred in one form or another in medical education and in healthcare more broadly. Different types of rationing exist in healthcare professional education. For example rationing may be implicit or explicit or may be based on macro-allocation or micro-allocation decisions. Funding can be distributed equally among learners, or according to the needs of individual learners, or to ensure that overall usefulness is maximised. One final option is to allow the market to operate freely and to decide in that way. These principles of rationing can apply to individual learners or to institutions or departments or learning modes. Rationing is occurring in medical education, even though it might be implicit. It is worth giving consideration to methods of rationing and to make thinking about rationing more explicit. PMID:27358649

  4. Kinematic Source Inversion Using Smoothly Curved Fault Model

    NASA Astrophysics Data System (ADS)

    Suzuki, W.; Aoi, S.; Sekiguchi, H.

    2010-12-01

    necessary to express the fault geometry as curved surface. In this study we develop an inversion method to derive a kinematic source rupture process using a curved fault model. The fault surface is mathematically presented by Non-Uniform Rational B-Spline (NURBS), which offers the flexible surface modeling. Multi-time-window linear waveform inversion scheme is implemented to the curved fault model. Points for calculating Green's function are generated at a shorter interval than subfaults for deriving slip history. This means that each subfault is also expressed by the curved surface, whereas the subfaults were based on the planar elements in most of previous studies that estimated source process on the curved fault. We apply the developed method to the 2008 Northern Iwate earthquake. Large slip areas are estimated at similar locations to the two-plane fault analysis. The synthetic waveforms agree with the observed ones comparably for both fault models. The total seismic moment is smaller for the curved fault than for the two-plane fault, which may indicate that inversion analysis using curved fault model could suppress artificial slip.

  5. Enculturated Chimpanzees Imitate Rationally

    ERIC Educational Resources Information Center

    Buttelmann, David; Carpenter, Malinda; Call, Josep; Tomasello, Michael

    2007-01-01

    Human infants imitate others' actions "rationally": they copy a demonstrator's action when that action is freely chosen, but less when it is forced by some constraint (Gergely, Bekkering & Kiraly, 2002). We investigated whether enculturated chimpanzees (Pan troglodytes) also imitate rationally. Using Gergely and colleagues' (2002) basic procedure,…

  6. Standby Gasoline Rationing Plan

    SciTech Connect

    1980-06-01

    The final rules adopted by the President for a Standby Gasoline Rationing Plan are presented. The plan provides that eligibility for ration allotments will be determined primarily on the basis of motor vehicle registrations, taking into account historical differences in the use of gasoline among states. The regulations also provide authority for supplemental allotments to firms so that their allotment will equal a specified percentage of gasoline use during a base period. Priority classifications, i.e., agriculture, defense, etc., are established to assure adequate gasoline supplies for designated essential services. Ration rights must be provided by end-users to their suppliers for each gallon sold. DOE will regulate the distribution of gasoline at the wholesale level according to the transfer by suppliers of redeemed ration rights and the gasoline allocation regulations. Ration rights are transferable. A ration banking system is created to facilitate transfers of ration rights. Each state will be provided with a reserve of ration rights to provide for hardship needs and to alleviate inequities. (DC)

  7. The tail plane

    NASA Technical Reports Server (NTRS)

    Munk, Max M

    1923-01-01

    This report deals with the calculation of the equilibrium, statistical stability, and damping of the tail plane. The author has simplified the present theory of longitudinal stability for the particular purpose of obtaining one definite coefficient characteristics of the effect of the tail plane. This coefficient is obtained by substituting certain aerodynamic characteristics and some dimensions of the airplane in a comparatively simple mathematical expression. Care has been taken to confine all aerodynamical information necessary for the calculation of the coefficient to the well-known curves representing the qualities of the wing section. This is done by making use of the present results of modern aerodynamics. All formulas and relations necessary for the calculation are contained in the paper. They give in some cases only an approximation of the real values. An example of calculation is added in order to illustrate the application of the method. The coefficient indicates not only whether the effect of the tail plane is great enough, but also whether it is not too great. It appears that the designer has to avoid a certain critical length of the fuselage, which inevitably gives rise to periodical oscillations of the airplane. The discussion also shows the way and in what direction to carry out experimental work.

  8. Orthogonal rational functions and quadrature on an interval

    NASA Astrophysics Data System (ADS)

    van Deun, J.; Bultheel, A.

    2003-04-01

    Rational functions with real poles and poles in the complex lower half-plane, orthogonal on the real line, are well known. Quadrature formulas similar to the Gauss formulas for orthogonal polynomials have been studied. We generalize to the case of arbitrary complex poles and study orthogonality on a finite interval. The zeros of the orthogonal rational functions are shown to satisfy a quadratic eigenvalue problem. In the case of real poles, these zeros are used as nodes in the quadrature formulas.

  9. F-theory and all things rational: surveying U(1) symmetries with rational sections

    NASA Astrophysics Data System (ADS)

    Lawrie, Craig; Schäfer-Nameki, Sakura; Wong, Jin-Mann

    2015-09-01

    We study elliptic fibrations for F-theory compactifications realizing 4d and 6d supersymmetric gauge theories with abelian gauge factors. In the fibration these U(1) symmetries are realized in terms of additional rational section. We obtain a universal characterization of all the possible U(1) charges of matter fields by determining the corresponding codimension two fibers with rational sections. In view of modelling supersymmetric Grand Unified Theories, one of the main examples that we analyze are U(1) symmetries for SU(5) gauge theories with overline{5} and 10 matter. We use a combination of constraints on the normal bundle of rational curves in Calabi-Yau three- and four-folds, as well as the splitting of rational curves in the fibers in codimension two, to determine the possible configurations of smooth rational sections. This analysis straightforwardly generalizes to multiple U(1)s. We study the flops of such fibers, as well as some of the Yukawa couplings in codimension three. Furthermore, we carry out a universal study of the U(1)-charged GUT singlets, including their KK-charges, and determine all realizations of singlet fibers. By giving vacuum expectation values to these singlets, we propose a systematic way to analyze the Higgsing of U(1)s to discrete gauge symmetries in F-theory.

  10. The Construction of Moral Rationality.

    ERIC Educational Resources Information Center

    Moshman, D.

    1995-01-01

    Offers a theoretical account of moral rationality within a rational constructivist paradigm examining the nature and relationship of rationality and reasoning. Suggests progressive changes through developmental levels of moral rationality. Proposes a developmental moral epistemology that accommodates moral pluralism to a greater degree than does…

  11. Bradford Curves.

    ERIC Educational Resources Information Center

    Rousseau, Ronald

    1994-01-01

    Discussion of informetric distributions shows that generalized Leimkuhler functions give proper fits to a large variety of Bradford curves, including those exhibiting a Groos droop or a rising tail. The Kolmogorov-Smirnov test is used to test goodness of fit, and least-square fits are compared with Egghe's method. (Contains 53 references.) (LRW)

  12. [Rational use of antibiotics].

    PubMed

    Walger, P

    2016-06-01

    International and national campaigns draw attention worldwide to the rational use of the available antibiotics. This has been stimulated by the high prevalence rates of drug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), a threatening spread of development of resistance in Gram-negative rod-shaped bacteria and the selection of Clostridium difficile with a simultaneous clear reduction in the development of new antibiotics. The implementation of antibiotic stewardship programs aims to maintain their effectiveness by a rational use of the available antibiotics. The essential target of therapy with antibiotics is successful treatment of individual patients with bacterial infections. The optimal clinical treatment results can only be achieved when the toxicity, selection of pathogens and development of resistance are minimized. This article presents the principles of a rational antibiotic therapy. PMID:27246321

  13. The ethics of rationing.

    PubMed

    Weale, A

    1995-10-01

    Rationing can occur at three levels of health care choice: the individual, the institutional and the social, with each level posing its own ethical problems. The institutional level is the focus of this paper. The principle of effectiveness may seem attractive, since it promises to ease the institutional dilemmas of rationing, but it is not straightforward to implement in the face of uncertainty. Greater efficiency also promises much, but concepts of benefit are contested and improving contractual performance has complications. Fairness can be a powerful criterion, but there are contested cases, for example age, where its meaning is unclear. Democratic responsiveness, for all its difficulties, is important to maintain in whatever process of rationing is chosen and this can be done by adopting some procedural devices. PMID:8556292

  14. Recursive rational choice

    SciTech Connect

    Lewis, A.A.

    1981-11-01

    It is the purpose of the present study to indicate the means by which Kramer's results may be generalized to considerations of stronger computing devices than the finite state automata considered in Kramer's approach, and to domains of alternatives having the cardinality of the continuum. The means we employ in the approach makes use of the theory of recursive functions in the context of Church's Thesis. The result, which we consider as a preliminary result to a more general research program, shows that a choice function that is rational in the sense of Richter (not necessarily regular) when defined on a restricted family of subsets of a continuum of alternatives, when recursively represented by a partial predicate on equivalence classes of approximations by rational numbers, is recursively unsolvable. By way of Church's Thesis, therefore, such a function cannot be realized by means of a very general class of effectively computable procedures. An additional consequence that can be derived from the result of recursive unsolvability of rational choice in this setting is the placement of a minimal bound on the amount of computational complexity entailed by effective realizations of rational choice.

  15. Rational Emotive Education

    ERIC Educational Resources Information Center

    Knaus, William

    1977-01-01

    Rational Emotive Education--an outgrowth of theories developed by Albert Ellis--is a teaching design of mental health concepts and problem-solving activities designed to help students to approach and cope with their problems through experiential learning, via a structured, thematic sequence of emotive education lessons. (MJB)

  16. Rationality and social behavior.

    PubMed

    Tullberg, Jan

    2003-10-21

    This article penetrates the relationship between social behavior and rationality. A critical analysis is made of efforts to classify some behaviors as altruistic, as they simultaneously meet criteria of rationality by not truly being self-destructive. Newcomb's paradox is one attempt to create a hybrid behavior that is both irrational and still meets some criterion of rationality. Such dubious rationality is often seen as a source of altruistic behavior. Group selection is a controversial topic. Sober and Wilson (Unto Others--The Evolution and Psychology of Unselfish Behavior, Harvard University Press, Cambridge, MA, 1998) suggest that a very wide concept of group selection might be used to explain altruism. This concept also includes kin selection and reciprocity, which blurs its focus. The latter mechanisms hardly need further arguments to prove their existence. This article suggests that it is group selection in a strict sense that should be investigated to limit semantic neologism and confusion. In evaluation, the effort to muster a mechanism for altruism out of group selection has not been successful. However, this is not the end to group selection, but rather a good reason to investigate more promising possibilities. There is little reason to burden group selection with the instability of altruism caused by altruistic members of a group having lower fitness than egoistic members. Group selection is much more likely to develop in combination with group egoism. A common project is supported by incitement against free riding, where conformist members joined in solidarity achieve a higher fitness than members pursuing more individualistic options. Group egoism is in no conflict with rationality, and the effects of group selection will be supported rather than threatened by individual selection. Empirical evidence indicates a high level of traits such as conformism and out-group antagonism in line with group egoism. These traits are also likely candidates for

  17. Rational enzyme redesign

    SciTech Connect

    Ornstein, R.L.

    1994-05-01

    Protein engineering is first a means of elucidating structure-function relations in an enzyme, and second, a means of changing a protein to make it serve a different, but generally related, purpose. In principle, one may change the functional characteristics of an enzyme by altering its substrate specificity, kinetics, optimum range of activity, and chemical mechanism. Obviously one cannot make all possible combinations of amino acid changes for even the smallest enzyme, so the essential question is which changes to make. The intent of rational protein/enzyme redesign is to alter a protein/enzyme in a timely and premeditated fashion. This article provides an outline of the process of rational enzyme redesign.

  18. Parabolic curves in Lie groups

    SciTech Connect

    Pauley, Michael

    2010-05-15

    To interpolate a sequence of points in Euclidean space, parabolic splines can be used. These are curves which are piecewise quadratic. To interpolate between points in a (semi-)Riemannian manifold, we could look for curves such that the second covariant derivative of the velocity is zero. We call such curves Jupp and Kent quadratics or JK-quadratics because they are a special case of the cubic curves advocated by Jupp and Kent. When the manifold is a Lie group with bi-invariant metric, we can relate JK-quadratics to null Lie quadratics which arise from another interpolation problem. We solve JK-quadratics in the Lie groups SO(3) and SO(1,2) and in the sphere and hyperbolic plane, by relating them to the differential equation for a quantum harmonic oscillator00.

  19. Monotonicity preserving splines using rational Ball cubic interpolation

    NASA Astrophysics Data System (ADS)

    Zakaria, Wan Zafira Ezza Wan; Jamal, Ena; Ali, Jamaludin Md.

    2015-10-01

    In scientific application and Computer Aided Design (CAD), users usually need to generate a spline passing through a given set of data which preserves certain shape properties of the data such as positivity, monotonicity or convexity [1]. The required curves have to be a smooth shape-preserving interpolation. In this paper a rational cubic spline in Ball representation is developed to generate an interpolant that preserves monotonicity. In this paper to control the shape of the interpolant three shape parameters are introduced. The shape parameters in the description of the rational cubic interpolation are subjected to monotonicity constrained. The necessary and sufficient conditions of the rational cubic interpolation are derived and visually the proposed rational cubic interpolant gives a very pleasing result.

  20. Rational management of epilepsy.

    PubMed

    Viswanathan, Venkataraman

    2014-09-01

    Management of epilepsies in children has improved considerably over the last decade, all over the world due to the advances seen in the understanding of the patho-physiology of epileptogenesis, availability of both structural and functional imaging studies along with better quality EEG/video-EEG recordings and the availability of a plethora of newer anti-epileptic drugs which are tailormade to act on specific pathways. In spite of this, there is still a long way to go before one is able to be absolutely rational about which drug to use for which type of epilepsy. There have been a lot of advances in the area of epilepsy surgery and is certainly gaining ground for specific cases. Better understanding of the genetic basis of epilepsies will hopefully lead to a more rational treatment plan in the future. Also, a lot of work needs to be done to dispel various misunderstandings and myths about epilepsy which still exists in our country. PMID:24871077

  1. Rational solutions to the KPI equation and multi rogue waves

    NASA Astrophysics Data System (ADS)

    Gaillard, Pierre

    2016-04-01

    We construct here rational solutions to the Kadomtsev-Petviashvili equation (KPI) as a quotient of two polynomials in x, y and t depending on several real parameters. This method provides an infinite hierarchy of rational solutions written in terms of polynomials of degrees 2 N(N + 1) in x, y and t depending on 2 N - 2 real parameters for each positive integer N. We give explicit expressions of the solutions in the simplest cases N = 1 and N = 2 and we study the patterns of their modulus in the (x , y) plane for different values of time t and parameters.

  2. Curves and Their Properties.

    ERIC Educational Resources Information Center

    Yates, Robert C.

    This volume, a reprinting of a classic first published in 1952, presents detailed discussions of 26 curves or families of curves, and 17 analytic systems of curves. For each curve the author provides a historical note, a sketch or sketches, a description of the curve, a discussion of pertinent facts, and a bibliography. Depending upon the curve,…

  3. Rational Approximations to Rational Models: Alternative Algorithms for Category Learning

    ERIC Educational Resources Information Center

    Sanborn, Adam N.; Griffiths, Thomas L.; Navarro, Daniel J.

    2010-01-01

    Rational models of cognition typically consider the abstract computational problems posed by the environment, assuming that people are capable of optimally solving those problems. This differs from more traditional formal models of cognition, which focus on the psychological processes responsible for behavior. A basic challenge for rational models…

  4. Semistable modifications of families of curves and compactified Jacobians

    NASA Astrophysics Data System (ADS)

    Esteves, Eduardo; Pacini, Marco

    2016-04-01

    Given a family of nodal curves, a semistable modification of it is another family made up of curves obtained by inserting chains of rational curves of any given length at certain nodes of certain curves of the original family. We give comparison theorems between torsion-free, rank-1 sheaves in the former family and invertible sheaves in the latter. We apply them to show that there are functorial isomorphisms between the compactifications of relative Jacobians of families of nodal curves constructed through Caporaso's approach and those constructed through Pandharipande's approach.

  5. Standard Mastery Curves and Skew Curves.

    ERIC Educational Resources Information Center

    Warries, Egbert

    The objective of the study is to convince educational researchers of the necessity for "standard mastery curves" for the graphical representation of scores on summative tests for a group of students. Attention is drawn to the study of theoretical and empirical skew curves in education and biology. Use of standard mastery curves and study of skew…

  6. A Viewpoint on the Quantity "Plane Angle"

    NASA Astrophysics Data System (ADS)

    Eder, W. E.

    1982-01-01

    Properties of the quantity "plane angle" are explored under the hypothesis that it is a dimensional quantity. The exploration proceeds especially with respect to the physical concept, its mathematical treatment, vector concepts, measurement theory, units of related quantities, engineering pragmatism, and SI. An attempt is made to bring these different relations into a rational, logical and consistent framework, and thus to justify the hypothesis. Various types of vectorial quantities are recognized, and their properties described with an outline of the necessary algebraic manipulations. The concept of plane angle is amplified, and its interdependence with the circular arc is explored. The resulting units of plane angle form a class of similar scales of measurement. Consequences of the confirmed hypothesis are developed for mathematical expressions involving trigonometric functions, rotational volumes and areas, mathematical limits, differentiation and series expansion. Consequences for mechanical rotational quantities are developed, with proposals for revisions to a number of expressions for derived units within SI. A revised definition for the quantity "plane angle" is stated to take account of the developed insights. There is a clear need to reconsider the status of plane angle and some other quantities within the international framework of SI.

  7. Reasoning, decision making and rationality.

    PubMed

    Evans, J S; Over, D E; Manktelow, K I

    1993-01-01

    It is argued that reasoning in the real world supports decision making and is aimed at the achievement of goals. A distinction is developed between two notions of rationality: rationality which is reasoning in such a way as to achieve one's goals--within cognitive constraints--and rationality which is reasoning by a process of logic. This dichotomy is related to the philosophical distinction between practical and theoretical reasoning. It is argued that logicality (rationality) does not provide a good basis for rationality and some psychological research on deductive reasoning is re-examined in this light. First, we review belief bias effects in syllogistic reasoning, and argue that the phenomena do not support the interpretations of irrationality that are often placed upon them. Second, we review and discuss recent studies of deontic reasoning in the Wason selection task, which demonstrate the decision making, and rational nature of reasoning in realistic contexts. The final section of the paper examines contemporary decision theory and shows how it fails, in comparable manner to formal logic, to provide an adequate model for assessing the rationality of human reasoning and decision making. PMID:8287673

  8. Comparison of Two Algebraic Methods for Curve/curve Intersection

    NASA Technical Reports Server (NTRS)

    Demontaudouin, Y.; Tiller, W.

    1985-01-01

    Most geometric modeling systems use either polynomial or rational functions to represent geometry. In such systems most computational problems can be formulated as systems of polynomials in one or more variables. Classical elimination theory can be used to solve such systems. Here Cayley's method of elimination is summarized and it is shown how it can best be used to solve the curve/curve intersection problem. Cayley's method was found to be a more straightforward approach. Furthermore, it is computationally simpler, since the elements of the Cayley matrix are one variable instead of two variable polynomials. Researchers implemented and tested both methods and found Cayley's to be more efficient. Six pairs of curves, representing mixtures of lines, circles, and cubic arcs were used. Several examples had multiple intersection points. For all six cases Cayley's required less CPU time than the other method. The average time ratio of method 1 to method 2 was 3.13:1, the least difference was 2.33:1, and the most dramatic was 6.25:1. Both of the above methods can be extended to solve the surface/surface intersection problem.

  9. Experiments with Planing Surfaces

    NASA Technical Reports Server (NTRS)

    Sottorf, W

    1934-01-01

    A previous report discusses the experimental program of a systematic exploration of all questions connected with the planing problem as well as the first fundamental results of the investigation of a flat planing surface. The present report is limited to the conversion of the model test data to full scale.

  10. Detoxifying the concept of rationing.

    PubMed

    Sabin, James

    2014-01-01

    Andrew Hantel's proposal for dealing with cancer drug shortages exemplifies the kind of clinician-led discussion of rationing the U.S. political process requires. I argue that the U.S. will not get a grip on healthcare cost escalation until we set true budgets for healthcare. We will not be able to do that until the public accepts that rationing, done right, is an ethical necessity, not an ethical abomination. Because endorsing rationing is a third rail for politicians, "top down" leadership is currently impossible. As a result, health professionals must lead a "bottom up" educational process. Hantel shows how this can be done. PMID:24972061

  11. Explicit superconic curves.

    PubMed

    Cho, Sunggoo

    2016-09-01

    Conics and Cartesian ovals are extremely important curves in various fields of science. In addition, aspheric curves based on conics are useful in optical design. Superconic curves, recently suggested by Greynolds, are extensions of both conics and Cartesian ovals and have been applied to optical design. However, they are not extensions of aspheric curves based on conics. In this work, we investigate another type of superconic curves. These superconic curves are extensions of not only conics and Cartesian ovals but also aspheric curves based on conics. Moreover, these are represented in explicit form, while Greynolds's superconic curves are in implicit form. PMID:27607506

  12. Crack growth measured on flat and curved surfaces at cryogenic temperatures

    NASA Technical Reports Server (NTRS)

    Orange, T. W.; Sullivan, T. L.

    1967-01-01

    Multiple element continuity gage measures plane stress crack growth plus surface crack growth under plane strain conditions. The gage measures flat and curved surfaces and operates at cryogenic temperatures.

  13. Managed care and efficient rationing.

    PubMed

    Rosenthal, Meredith B; Newhouse, Joseph P

    2002-01-01

    Widespread dissatisfaction with managed care has led to calls for major reform and consumer protection. Although some have concluded that managed care backlash is simply a result of too much rationing, we propose an alternative view that focuses on the nature of services eliminated by managed care. In particular, we point out that managed care rations services largely without regard to consumer preferences. We question whether managed care's emphasis on supply-side control of moral hazard is consistent with the principles of efficient rationing. Further research on the nature of provider and consumer rationing decisions is needed to inform the design of supply-side and demand-side incentives that will lead to an efficient allocation of services. PMID:12148660

  14. The rationing agenda in the NHS. Rationing Agenda Group.

    PubMed

    New, B

    1996-06-22

    The Rationing Agenda Group has been founded to deepen the British debate on rationing health care. It believes that rationing in health care is inevitable and that the public must be involved in the debate about issues relating to rationing. The group comprises people from all parts of health care, none of whom represent either their group or their institutions. RAG has begun by producing this document, which attempts to set an agenda of all the issues that need to be considered when debating the rationing of health care. We hope for responses to the document. The next stage will be to incorporate the responses into the agenda. Then RAG will divide the agenda into manageable chunks and commission expert, detailed commentaries. From this material a final paper will be published and used to prompt public debate. This stage should be reached early in 1997. While these papers are being prepared RAG is developing ways to involve the public in the debate and evaluate the whole process. We present as neutrally as possible all the issues related to rationing and priority setting in the NHS. We focus on the NHS for two reasons. Firstly, for those of us resident in the United Kingdom the NHS is the health care system with which we are most familiar and most concerned. Secondly, focusing on one system alone allows more coherent analysis than would be possible if issues in other systems were included as well. Our concern is with the delivery of health care, not its finance, though we discuss the possible effects of changing the financing system of the NHS. Finally, though our position is neutral, we hold two substantive views--namely, that rationing is unavoidable and that there should be more explicit debate about the principles and issues concerned. We consider the issues under four headings: preliminaries, ethics, democracy, and empirical questions. Preliminaries deal with the semantics of rationing, whether rationing is necessary, and with the range of services to which

  15. The rationing agenda in the NHS. Rationing Agenda Group.

    PubMed Central

    New, B.

    1996-01-01

    The Rationing Agenda Group has been founded to deepen the British debate on rationing health care. It believes that rationing in health care is inevitable and that the public must be involved in the debate about issues relating to rationing. The group comprises people from all parts of health care, none of whom represent either their group or their institutions. RAG has begun by producing this document, which attempts to set an agenda of all the issues that need to be considered when debating the rationing of health care. We hope for responses to the document. The next stage will be to incorporate the responses into the agenda. Then RAG will divide the agenda into manageable chunks and commission expert, detailed commentaries. From this material a final paper will be published and used to prompt public debate. This stage should be reached early in 1997. While these papers are being prepared RAG is developing ways to involve the public in the debate and evaluate the whole process. We present as neutrally as possible all the issues related to rationing and priority setting in the NHS. We focus on the NHS for two reasons. Firstly, for those of us resident in the United Kingdom the NHS is the health care system with which we are most familiar and most concerned. Secondly, focusing on one system alone allows more coherent analysis than would be possible if issues in other systems were included as well. Our concern is with the delivery of health care, not its finance, though we discuss the possible effects of changing the financing system of the NHS. Finally, though our position is neutral, we hold two substantive views--namely, that rationing is unavoidable and that there should be more explicit debate about the principles and issues concerned. We consider the issues under four headings: preliminaries, ethics, democracy, and empirical questions. Preliminaries deal with the semantics of rationing, whether rationing is necessary, and with the range of services to which

  16. Optical conductivity of curved graphene.

    PubMed

    Chaves, A J; Frederico, T; Oliveira, O; de Paula, W; Santos, M C

    2014-05-01

    We compute the optical conductivity for an out-of-plane deformation in graphene using an approach based on solutions of the Dirac equation in curved space. Different examples of periodic deformations along one direction translates into an enhancement of the optical conductivity peaks in the region of the far- and mid-infrared frequencies for periodicities ∼100 nm. The width and position of the peaks can be changed by dialling the parameters of the deformation profiles. The enhancement of the optical conductivity is due to intraband transitions and the translational invariance breaking in the geometrically deformed background. Furthermore, we derive an analytical solution of the Dirac equation in a curved space for a general deformation along one spatial direction. For this class of geometries, it is shown that curvature induces an extra phase in the electron wave function, which can also be explored to produce interference devices of the Aharonov-Bohm type. PMID:24759188

  17. Fourier plane imaging microscopy

    SciTech Connect

    Dominguez, Daniel Peralta, Luis Grave de; Alharbi, Nouf; Alhusain, Mdhaoui; Bernussi, Ayrton A.

    2014-09-14

    We show how the image of an unresolved photonic crystal can be reconstructed using a single Fourier plane (FP) image obtained with a second camera that was added to a traditional compound microscope. We discuss how Fourier plane imaging microscopy is an application of a remarkable property of the obtained FP images: they contain more information about the photonic crystals than the images recorded by the camera commonly placed at the real plane of the microscope. We argue that the experimental results support the hypothesis that surface waves, contributing to enhanced resolution abilities, were optically excited in the studied photonic crystals.

  18. A Simple Experiment Demonstrating the Relationship between Response Curves and Absorption Spectra.

    ERIC Educational Resources Information Center

    Li, Chia-yu

    1984-01-01

    Describes an experiment for recording two individual spectrophotometer response curves. The two curves are directly related to the power of transmitted beams that pass through a solvent and solution. An absorption spectrum of the solution can be constructed from the calculated rations of the curves as a function of wavelength. (JN)

  19. Diffusion-limited aggregation on curved surfaces

    NASA Astrophysics Data System (ADS)

    Choi, J.; Crowdy, D.; Bazant, M. Z.

    2010-08-01

    We develop a general theory of transport-limited aggregation phenomena occurring on curved surfaces, based on stochastic iterated conformal maps and conformal projections to the complex plane. To illustrate the theory, we use stereographic projections to simulate diffusion-limited aggregation (DLA) on surfaces of constant Gaussian curvature, including the sphere (K>0) and the pseudo-sphere (K<0), which approximate "bumps" and "saddles" in smooth surfaces, respectively. Although the curvature affects the global morphology of the aggregates, the fractal dimension (in the curved metric) is remarkably insensitive to curvature, as long as the particle size is much smaller than the radius of curvature. We conjecture that all aggregates grown by conformally invariant transport on curved surfaces have the same fractal dimension as DLA in the plane. Our simulations suggest, however, that the multifractal dimensions increase from hyperbolic (K<0) to elliptic (K>0) geometry, which we attribute to curvature-dependent screening of tip branching.

  20. 2. VIEW SOUTH, INCLINE PLANE CAR, INCLINE PLANE TRACK, UPPER ...

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

    2. VIEW SOUTH, INCLINE PLANE CAR, INCLINE PLANE TRACK, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  1. Sibling Curves and Complex Roots 2: Looking Ahead

    ERIC Educational Resources Information Center

    Harding, Ansie; Engelbrecht, Johann

    2007-01-01

    This paper, the second of a two part article, expands on an idea that appeared in literature in the 1950s to show that by restricting the domain to those complex numbers that map onto real numbers, representations of functions other than the ones in the real plane are obtained. In other words, the well-known curves in the real plane only depict…

  2. Rationalizing the Promotion of Non-Rational Behaviors in Organizations.

    ERIC Educational Resources Information Center

    Smith, Peter A. C.; Sharma, Meenakshi

    2002-01-01

    Organizations must balance rational/technical efficiency and emotions. Action learning has been proven to be effective for developing emotional openness in the workplace. Facilitators of action learning should draw upon the disciplines of counseling, Gestalt, psychodynamics, and Eastern philosophies. (Contains 23 references.) (SK)

  3. SNAP focal plane

    SciTech Connect

    Lampton, Michael L.; Kim, A.; Akerlof, C.W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Berkovitz, J.; Bernstein, G.; Bester, M.; Bonissent, A.; Bower, C.; Carithers Jr., W.C.; Commins, E.D.; Day, C.; Deustua, S.E.; DiGennaro,R.; Ealet, A.; Ellis, R.S.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar, A.; Groom, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Holland, S.E.; Huterer, D.; Karcher, A.; Kolbe, W.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, M.E.; Levin, D.S.; Linder,E.V.; Loken, S.C.; Malina, R.; Massey, R.; McKay, T.; McKee, S.P.; Miquel, R.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto, E.; Refregier, A.; Rhodes, J.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tarle, G.; Tomasch,A.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, G.

    2002-07-29

    The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square-degree field sensitive in the visible and near-infrared wavelength regime. We describe the requirements for the instrument suite and the evolution of the focal plane design to the present concept in which all the instrumentation--visible and near-infrared imagers, spectrograph, and star guiders--share one common focal plane.

  4. Spectral Methods Using Rational Basis Functions on an Infinite Interval

    NASA Astrophysics Data System (ADS)

    Boyd, John P.

    1987-03-01

    By using the map y = L cot( t) where L is a constant, differential equations on the interval yɛ [- ∞, ∞] can be transformed into tɛ [0, π] and solved by an ordinary Fourier series. In this article, earlier work by Grosch and Orszag ( J. Comput. Phys.25, 273 (1977)), Cain, Ferziger, and Reynolds ( J. Comput. Phys.56, 272 (1984)), and Boyd ( J. Comput. Phys.25, 43 (1982); 57, 454 (1985); SIAM J. Numer. Anal. (1987)) is extended in several ways. First, the series of orthogonal rational functions converge on the exterior of bipolar coordinate surfaces in the complex y-plane. Second, Galerkin's method will convert differential equations with polynomial or rational coefficients into banded matrix problems. Third, with orthogonal rational functions it is possible to obtain exponential convergence even for u( y) that asymptote to a constant although this behavior would wreck alternatives such as Hermite or sinc expansions. Fourth, boundary conditions are usually "natural" rather than "essential" in the sense that the singularities of the differential equation will force the numerical solution to have the correct behavior at infinity even if no constraints are imposed on the basis functions. Fifth, mapping a finite interval to an infinite one and then applying the rational Chebyshev functions gives an exponentially convergent method for functions with bounded endpoint singularities. These concepts are illustrated by five numerical examples.

  5. Rational Suicide among the Elderly.

    ERIC Educational Resources Information Center

    Humphry, Derek

    1992-01-01

    Contends that old age, in and of itself, should never need to be a cause for self-destruction. Further argues that suicide and assisted suicide carried out in the face of terminal illness causing unbearable suffering should be ethically and legally acceptable. Outlines a perspective on rational suicide among the elderly. (Author/NB)

  6. Rational Exponentials and Continued Fractions

    ERIC Educational Resources Information Center

    Denny, J. K.

    2012-01-01

    Using continued fraction expansions, we can approximate constants, such as pi and e, using an appropriate integer n raised to the power x[superscript 1/x], x a suitable rational. We review continued fractions and give an algorithm for producing these approximations.

  7. On Counting the Rational Numbers

    ERIC Educational Resources Information Center

    Almada, Carlos

    2010-01-01

    In this study, we show how to construct a function from the set N of natural numbers that explicitly counts the set Q[superscript +] of all positive rational numbers using a very intuitive approach. The function has the appeal of Cantor's function and it has the advantage that any high school student can understand the main idea at a glance…

  8. Teaching Rational Decision-Making.

    ERIC Educational Resources Information Center

    Woolever, Roberts

    1978-01-01

    Presented is an outline of a college course, "Education in American Society," that focused on teaching students rational decision-making skills while examining current issues in American Education. The outline is followed by student comments, reactions, and evaluations of the course. (JMD)

  9. Beamlet focal plane diagnostic

    SciTech Connect

    Caird, J.A.; Nielsen, N.D.; Patton, H.G.; Seppala, L.G.; Thompson, C.E.; Wegner, P.J.

    1996-12-01

    This paper describes the major optical and mechanical design features of the Beamlet Focal Plane Diagnostic system as well as measurements of the system performance, and typical data obtained to date. We also discuss the NIF requirements on the focal spot that we are interested in measuring, and some of our plans for future work using this system.

  10. DLCQ and plane wave matrix Big Bang models

    NASA Astrophysics Data System (ADS)

    Blau, Matthias; O'Loughlin, Martin

    2008-09-01

    We study the generalisations of the Craps-Sethi-Verlinde matrix big bang model to curved, in particular plane wave, space-times, beginning with a careful discussion of the DLCQ procedure. Singular homogeneous plane waves are ideal toy-models of realistic space-time singularities since they have been shown to arise universally as their Penrose limits, and we emphasise the role played by the symmetries of these plane waves in implementing the flat space Seiberg-Sen DLCQ prescription for these curved backgrounds. We then analyse various aspects of the resulting matrix string Yang-Mills theories, such as the relation between strong coupling space-time singularities and world-sheet tachyonic mass terms. In order to have concrete examples at hand, in an appendix we determine and analyse the IIA singular homogeneous plane wave - null dilaton backgrounds.

  11. "The Bell Curve": Ringing in the Contract with America.

    ERIC Educational Resources Information Center

    Farrell, Walter C., Jr.; And Others

    1995-01-01

    Herrnstein and Murray's "The Bell Curve" claims that IQ is hereditary and that African Americans consistently score 15 points lower than other racial groups. Coolly received by academics, the book is being warmly embraced by Republican politicians endorsing fiscal austerity and social mean-spiritedness. The book rationalizes a conservative…

  12. Self-calibration of Antenna Errors Using Focal Plane Arrays

    NASA Astrophysics Data System (ADS)

    Napier, P. J.; Cornwell, T. J.

    The thery of focal-plane correlation is reviewed and applied to the problem of the self-calibration and self-correction of a radio telescope with errors in its reflecting surface. Curves are presented which allow the estimation of focal-plane array size and integration time needed for telescopes with varying amounts of error. It is suggested that the technique may have application to the problem of the construction of large telescopes in space.

  13. A variational characterization and geometric integration for Bertrand curves

    NASA Astrophysics Data System (ADS)

    Lucas, Pascual; Ortega-Yagües, José Antonio

    2013-04-01

    In this paper, we introduce a class of functionals, in the three-dimensional semi-Euclidean space {R}^3_q, having an energy density that depends only on curvature and whose moduli space of trajectories consists of LW-curves, i.e., curves with curvature κ and torsion τ for which there are three real constants λ, μ, ρ such that λκ + μτ = ρ, with λ2 + μ2 > 0. This family of curves includes plane curves, helices, curves of constant curvature, curves of constant torsion, Lancret curves (also called generalized helices), and Bertrand curves. We present an algorithm to construct Bertrand curves in {R}^3_q by using an arclength parametrized curve in a totally umbilical surface {S}^2, {S}^2_1, or {H}^2 and prove that every Bertrand curve in {R}^3_q can be obtained in this way. A second algorithm is presented for the construction of LW-curves by using a curve of constant slope in the ruled surface Sα whose directrix is a certain curve α with non-zero curvature and whose rulings are generated by its modified Darboux vector field.

  14. A method of plane geometry primitive presentation

    NASA Astrophysics Data System (ADS)

    Jiao, Anbo; Luo, Haibo; Chang, Zheng; Hui, Bin

    2014-11-01

    Point feature and line feature are basic elements in object feature sets, and they play an important role in object matching and recognition. On one hand, point feature is sensitive to noise; on the other hand, there are usually a huge number of point features in an image, which makes it complex for matching. Line feature includes straight line segment and curve. One difficulty in straight line segment matching is the uncertainty of endpoint location, the other is straight line segment fracture problem or short straight line segments joined to form long straight line segment. While for the curve, in addition to the above problems, there is another difficulty in how to quantitatively describe the shape difference between curves. Due to the problems of point feature and line feature, the robustness and accuracy of target description will be affected; in this case, a method of plane geometry primitive presentation is proposed to describe the significant structure of an object. Firstly, two types of primitives are constructed, they are intersecting line primitive and blob primitive. Secondly, a line segment detector (LSD) is applied to detect line segment, and then intersecting line primitive is extracted. Finally, robustness and accuracy of the plane geometry primitive presentation method is studied. This method has a good ability to obtain structural information of the object, even if there is rotation or scale change of the object in the image. Experimental results verify the robustness and accuracy of this method.

  15. Analytical investigation of curved steel girder behaviour

    NASA Astrophysics Data System (ADS)

    Simpson, Michael Donald

    Horizontally curved bridges meet an increasing demand for complex highway geometries in congested urban areas. A popular type of curved bridge consists of steel I-girders interconnected by cross-frames and a composite concrete deck slab. Prior to hardening of the concrete deck each I-girder is susceptible to a lateral torsional buckling-type failure. Unlike a straight I-girder, a curved I-girder resists major components of stress resulting from strong axis bending, weak axis bending and warping. The combination of these stresses reduce the available strength of a curved girder versus that of an equivalent straight girder. Experiments demonstrating the ultimate strength characteristics of curved girders are few in number. Of the available experimental research, few studies have used full scale-tests and boundary conditions indicative of those found in an actual bridge structure. Unlike straight girders, curved girders are characterized by nonlinear out-of-plane deformations which, depending upon the magnitude of curvature, may occur at very low load levels. Because of the inherent nonlinear behaviour, some have questioned the application of the term lateral torsional buckling to curved girders; rather curved girders behave in a manner consistent with a deflection-amplification problem. Even with the advent of sophisticated analytical techniques, there is a glaring void in the documented literature regarding calibration of these techniques with known experimental curved girder behaviour. Presented here is an analytical study of the nonlinear modelling of curved steel girders and bridges. This is accomplished by incorporating large deflection and nonlinear material behaviour into three dimensional finite element models generated using the program ANSYS. Emphasis is placed on the calibration of the finite method with known experimental ultimate strength data. It is demonstrated that accurate predictions of load deformation and ultimate strength are attainable via the

  16. Bacterial streamers in curved microchannels

    NASA Astrophysics Data System (ADS)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  17. Psychology and the Rationality of Emotion*

    PubMed Central

    Clore, Gerald L.

    2014-01-01

    Questions addressed by recent psychological research on emotion include questions about how thought shapes emotion and how emotion, in turn, shapes thought. Research on emotion and cognition paints a somewhat different picture than that seen in traditional discussions of passion and reason. This article reviews several aspects of this research, concentrating specifically on three views of rationality: Rationality as Process, Rationality as Product, and Rationality as Outcome. PMID:25125770

  18. Lower extremity kinematics of athletics curve sprinting.

    PubMed

    Alt, Tobias; Heinrich, Kai; Funken, Johannes; Potthast, Wolfgang

    2015-01-01

    Curve running requires the generation of centripetal force altering the movement pattern in comparison to the straight path run. The question arises which kinematic modulations emerge while bend sprinting at high velocities. It has been suggested that during curve sprints the legs fulfil different functions. A three-dimensional motion analysis (16 high-speed cameras) was conducted to compare the segmental kinematics of the lower extremity during the stance phases of linear and curve sprints (radius: 36.5 m) of six sprinters of national competitive level. Peak joint angles substantially differed in the frontal and transversal plane whereas sagittal plane kinematics remained unchanged. During the prolonged left stance phase (left: 107.5 ms, right: 95.7 ms, straight: 104.4 ms) the maximum values of ankle eversion (left: 12.7°, right: 2.6°, straight: 6.6°), hip adduction (left: 13.8°, right: 5.5°, straight: 8.8°) and hip external rotation (left: 21.6°, right: 12.9°, straight: 16.7°) were significantly higher. The inside leg seemed to stabilise the movement in the frontal plane (eversion-adduction strategy) whereas the outside leg provided and controlled the motion in the horizontal plane (rotation strategy). These results extend the principal understanding of the effects of curve sprinting on lower extremity kinematics. This helps to increase the understanding of nonlinear human bipedal locomotion, which in turn might lead to improvements in athletic performance and injury prevention. PMID:25495196

  19. Rationality and the Logic of Good Reasons.

    ERIC Educational Resources Information Center

    Fisher, Walter R.

    This paper contends that the rationality of the logic of good reasons is constituted in its use. To support this claim, the paper presents an analysis of the relationship between being reasonable and being rational. It then considers how following the logic of good reasons leads to rationality in the behavior of individuals and groups; the latter…

  20. Rational Thinking in School-Based Practice

    ERIC Educational Resources Information Center

    Clark, Mary Kristen; Flynn, Perry

    2011-01-01

    Purpose: We reflect on Alan Kamhi's (2011) prologue on balancing certainty and uncertainty as it pertains to school-based practice. Method: In schools, rational thinking depends on effective team processes, much like professional learning communities. We consider the conditions that are required for rational thinking and how rational team dialogue…

  1. Book Selection, Collection Development, and Bounded Rationality.

    ERIC Educational Resources Information Center

    Schwartz, Charles A.

    1989-01-01

    Reviews previously proposed schemes of classical rationality in book selection, describes new approaches to rational choice behavior, and presents a model of book selection based on bounded rationality in a garbage can decision process. The role of tacit knowledge and symbolic content in the selection process are also discussed. (102 references)…

  2. Large-degree asymptotics of rational Painlevé-II functions: critical behaviour

    NASA Astrophysics Data System (ADS)

    Buckingham, Robert J.; Miller, Peter D.

    2015-06-01

    This paper is a continuation of our analysis, begun in Buckingham and Miller (2014 Nonlinearity 27 2489-577), of the rational solutions of the inhomogeneous Painlevé-II equation and associated rational solutions of the homogeneous coupled Painlevé-II system in the limit of large degree. In this paper we establish asymptotic formulae valid near a certain curvilinear triangle in the complex plane that was previously shown to separate two distinct types of asymptotic behaviour. Our results display both a trigonometric degeneration of the rational Painlevé-II functions and also a degeneration to the tritronquée solution of the Painlevé-I equation. Our rigorous analysis is based on the steepest descent method applied to a Riemann-Hilbert representation of the rational Painlevé-II functions, and supplies leading-order formulae as well as error estimates.

  3. Analysis of Basal Plane Bending and Basal Plane Dislocations in 4H-SiC Single Crystals

    NASA Astrophysics Data System (ADS)

    Ohtani, Noboru; Katsuno, Masakazu; Fujimoto, Tatsuo; Nakabayashi, Masashi; Tsuge, Hiroshi; Yashiro, Hirokatsu; Aigo, Takashi; Hirano, Hosei; Hoshino, Taizo; Ohashi, Wataru

    2009-06-01

    4H-SiC single crystals were grown by the physical vapor transport (PVT) growth method under different thermoelastic stress conditions, and the degree of basal plane bending in the crystals was characterized by the peak shift measurement of X-ray rocking curves. The results indicate that the degree of basal plane bending largely depends on the magnitude of the thermoelastic stresses imposed on the crystals during PVT growth. Quantitative analysis of basal plane bending revealed that the density of basal plane dislocations (BPDs) estimated from basal plane bending is much smaller than that obtained from defect-selective etching. It was also found that the BPD density is correlated with the threading screw dislocation (TSD) density in PVT-grown SiC crystals. These aspects of BPDs were discussed in terms of the BPD multiplication process triggered by the intersection of BPDs with a forest of TSDs extending along the c-axis.

  4. Flow-duration curves

    USGS Publications Warehouse

    Searcy, James Kincheon

    1959-01-01

    The flow-duration curve is a cumulative frequency curve that shows the percent of time specified discharges were equaled or exceeded during a given period. It combines in one curve the flow characteristics of a stream throughout the range of discharge, without regard to the sequence of occurrence. If the period upon which the curve is based represents the long-term flow of a stream, the curve may be used to predict the distribution of future flows for water- power, water-supply, and pollution studies. This report shows that differences in geology affect the low-flow ends of flow-duration curves of streams in adjacent basins. Thus, duration curves are useful in appraising the geologic characteristics of drainage basins. A method for adjusting flow-duration curves of short periods to represent long-term conditions is presented. The adjustment is made by correlating the records of a short-term station with those of a long-term station.

  5. Anodic Polarization Curves Revisited

    ERIC Educational Resources Information Center

    Liu, Yue; Drew, Michael G. B.; Liu, Ying; Liu, Lin

    2013-01-01

    An experiment published in this "Journal" has been revisited and it is found that the curve pattern of the anodic polarization curve for iron repeats itself successively when the potential scan is repeated. It is surprising that this observation has not been reported previously in the literature because it immediately brings into…

  6. The Skipping Rope Curve

    ERIC Educational Resources Information Center

    Nordmark, Arne; Essen, Hanno

    2007-01-01

    The equilibrium of a flexible inextensible string, or chain, in the centrifugal force field of a rotating reference frame is investigated. It is assumed that the end points are fixed on the rotation axis. The shape of the curve, the skipping rope curve or "troposkien", is given by the Jacobi elliptic function sn. (Contains 3 figures.)

  7. NURBS distance fields for extremely curved cracks

    NASA Astrophysics Data System (ADS)

    Sevilla, Ruben; Barbieri, Ettore

    2014-12-01

    This paper proposes for the first time an intrinsic enrichment for extremely curved cracks in a meshfree framework. The unique property of the proposed method lies in the exact geometric representation of cracks using non-uniform rational B-splines (NURBS). A distance function algorithm for NURBS is presented, resulting in a spatial field which is simultaneously discontinuous over the (finite) curved crack and continuous all around the crack tips. Numerical examples show the potential of the proposed approach and illustrate its advantages with respect to other techniques usually employed to model fracture, including standard finite elements with remeshing and the extended finite element method. This work represents a further step in an ongoing effort in the community to integrate computer aided design with numerical simulations.

  8. Propagation of guided modes in curved nanoribbon waveguides

    SciTech Connect

    Yang, P.; Ye, Zhuo; Hu, Xinhua; Li, Ming; Ho, Kai-Ming

    2006-08-23

    The authors develop a plane-wave-based transfer matrix method in curvilinear coordinates to study the guided modes in curved nanoribbon waveguides. The problem of a curved structure is transformed into an equivalent one of a straight structure with spatially dependent tensors of dielectric constant and magnetic permeability. The authors investigate the coupling between the eigenmodes of the straight part and those of the curved part when the waveguide is bent. The authors show that curved sections can result in strong oscillations in the transmission spectrum similar to the recent experimental results of Lawet al.

  9. Degeneration of the Julia set to singular loci of algebraic curves

    NASA Astrophysics Data System (ADS)

    Saito, Satoru; Saitoh, Noriko; Harada, Hiromitsu; Yumibayashi, Tsukasa; Wakimoto, Yuki

    2013-06-01

    We show that, when a non-integrable rational map changes to an integrable one continuously, a large part of the Julia set of the map approach indeterminate points (IDP) of the map along algebraic curves. We will see that the IDPs are singular loci of the curves.

  10. Fourier plane image amplifier

    DOEpatents

    Hackel, Lloyd A.; Hermann, Mark R.; Dane, C. Brent; Tiszauer, Detlev H.

    1995-01-01

    A solid state laser is frequency tripled to 0.3 .mu.m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only .about.1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power.

  11. Fourier plane image amplifier

    DOEpatents

    Hackel, L.A.; Hermann, M.R.; Dane, C.B.; Tiszauer, D.H.

    1995-12-12

    A solid state laser is frequency tripled to 0.3 {micro}m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only about 1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power. 1 fig.

  12. Mosaic Focal Plane Development

    NASA Astrophysics Data System (ADS)

    Mason, David L.; Horner, Scott D.; Aamodt, Earl K.

    2002-12-01

    Advances in systems engineering, applied sciences, and manufacturing technologies have enabled the development of large ground based and spaced based astronomical instruments having a large Field of View (FOV) to capture a large portion of the universe in a single image. A larger FOV can be accomplished using light weighted optical elements, improved support structures, and the development of mosaic Focal Plane Assemblies (mFPA). A mFPA designed for astronomy can use multiple Charged Coupled Devices (CCD) mounted onto a single camera baseplate integrated at the instrument plane of focus. Examples of current, or proposed, missions utilizing mFPA technology include FAME, GEST, Kepler, GAIA, LSST, and SNAP. The development of a mFPA mandates tighter control on the design trades, component development, CCD characterization, component integration, and performance verification testing. This paper addresses the capability Lockheed Martin Space Systems Company's (LMSSC) Advanced Technology Center (ATC) has developed to perform CCD characterization, mFPA assembly and alignment, and mFPA system level testing.

  13. Mosaic Focal Plane Development

    NASA Astrophysics Data System (ADS)

    Mason, D.; Horner, S.; Aamodt, E.

    Advances in manufacturing and applied sciences have enabled the development of large ground and spaced based astronomical instruments having a Field of View (FOV) large enough to capture a large portion of the universe in a single image. A large FOV can be accomplished using light weighted optics, improved structures, and the development of mosaic Focal Plane Assemblies (mFPAs). A mFPA comprises multiple Charged Coupled Devices (CCD) mounted onto a single baseplate integrated at the focus plane of the instrument. Examples of current, or proposed, missions utilizing mFPA technology include FAME, GEST, Kepler, GAIA, LSST, and SNAP. The development of a mFPA mandates tight control on the design trades of component development, CCD definition and characterization, component integration, and performance verification testing. This paper addresses the results of the Lockheed Martin Space Systems Company (LMSSC), Advanced Technology Center (ATC) developed mFPA. The design trades and performance characterization are services provided by the LMSSC ATC but not detailed in this paper.

  14. Out-of-plane properties

    NASA Technical Reports Server (NTRS)

    Jackson, Wade C.; Portanova, Marc A.

    1995-01-01

    This paper summarizes three areas of research which were performed to characterize out-of-plane properties of composite materials. In the first investigation, a series of tests was run to characterize the through-the-thickness tensile strength for a variety of composites that included 2D braids, 2D and 3D weaves, and prepreg tapes. A new test method based on a curved beam was evaluated. Failures were significantly different between the 2D materials and the 3D weaves. The 2D materials delaminated between layers due to out-of-plane tensile stresses while the 3D weaves failed due to the formation of radial cracks between the surface plies caused by high circumferential stresses along the inner radius. The strength of the 2D textile composites did not increase relative to the tapes. Final failure in the 3D weaves was caused by a circumferential crack similar to the 2D materials and occurred at a lower bending moment than in other materials. The early failures in the 3D weaves were caused by radial crack formation rather than a low through-the-thickness strength. The second investigation focused on the development of a standard impact test method to measure impact damage resistance. The only impact tests that currently exist are compression after impact (CAI) tests which incorporate elements of both damage resistance and damage tolerance. A new impact test method is under development which uses a quasi-static indentation (QSI) test to directly measure damage resistance. Damage resistance is quantified in terms of the contact force to produce a unit of damage where a metric for damage may be area in C-scan, depth of residual dent , penetration, damage growth, etc. A final draft of an impact standard that uses a QSI test method will be presented to the ASTM Impact Task Group on impact. In the third investigation, the impact damage resistance behavior of a variety of textile materials was studied using the QSI test method. In this study, the force where large damage

  15. The Three Planes of Language.

    ERIC Educational Resources Information Center

    Sampson, Gloria

    1999-01-01

    Currently, the language sciences place together four different forms of mental activity on one plane of language, which results in confusion. This paper presents arguments from metaphysics, hermeneutics, and semiotics to demonstrate that there are actually three planes of language (a biologically-based information processing plane, a literal…

  16. Rational exemption to vaccination for non-fatal SIS diseases: globally stable and oscillatory endemicity.

    PubMed

    Buonomo, Bruno; D'Onofrio, Alberto; Lacitignola, Deborah

    2010-07-01

    'Rational' exemption to vaccination is due to a pseudo-rational comparison between the low risk of infection, and the perceived risk of side effects from the vaccine. Here we consider rational exemption in an SI model with information dependent vaccination where individuals use information on the disease's spread as their information set. Using suitable assumptions, we show the dynamic implications of the interaction between rational exemption, current and delayed information. In particular, if vaccination decisions are based on delayed informations, we illustrate both global attractivity to an endemic state, and the onset, through Hopf bifurcations, of general Yakubovich oscillations. Moreover, in some relevant cases, we plot the Hopf bifurcation curves and we give a behavioural interpretation of their meaning. PMID:20578786

  17. Mechanics of Curved Folds

    NASA Astrophysics Data System (ADS)

    Dias, Marcelo A.; Santangelo, Christian D.

    2011-03-01

    Despite an almost two thousand year history, origami, the art of folding paper, remains a challenge both artistically and scientifically. Traditionally, origami is practiced by folding along straight creases. A whole new set of shapes can be explored, however, if, instead of straight creases, one folds along arbitrary curves. We present a mechanical model for curved fold origami in which the energy of a plastically-deformed crease is balanced by the bending energy of developable regions on either side of the crease. Though geometry requires that a sheet buckle when folded along a closed curve, its shape depends on the elasticity of the sheet. NSF DMR-0846582.

  18. Intertwined Hamiltonians in two-dimensional curved spaces

    SciTech Connect

    Aghababaei Samani, Keivan . E-mail: samani@cc.iut.ac.ir; Zarei, Mina

    2005-04-01

    The problem of intertwined Hamiltonians in two-dimensional curved spaces is investigated. Explicit results are obtained for Euclidean plane, Minkowski plane, Poincare half plane (AdS{sub 2}), de Sitter plane (dS{sub 2}), sphere, and torus. It is shown that the intertwining operator is related to the Killing vector fields and the isometry group of corresponding space. It is shown that the intertwined potentials are closely connected to the integral curves of the Killing vector fields. Two problems are considered as applications of the formalism presented in the paper. The first one is the problem of Hamiltonians with equispaced energy levels and the second one is the problem of Hamiltonians whose spectrum is like the spectrum of a free particle.

  19. NASA Connect: 'Plane Weather'

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Excerpt from the NASA Connect show 'Plane Weather' This clip explains how our weather occurs, and why Solar radiation is responsible. Weather affects our daily lives. The elements of weather: rain, wind, fog, ice and snow affect the operation and flight of an airplane. In this program, NASA and FAA researchers will introduce students to math, science, and weather; demonstrate how these elements influence flight; and show how NASA and FAA research is used to limit the effects of these elements on flight. Students will examine: the tools, techniques, and technologies used by engineers and scientists to detect these and other climatological factors affecting aircraft in flight. The lesson and classroom experiment will involve students in the scientific process and emphasizing problem solving, measurement, and reasoning skills.

  20. NASA Connect: 'Plane Weather'

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Excerpt from the NASA Connect show 'Plane Weather' This clip explains what high and low pressure weather systems are, and how they form. Weather affects our daily lives. The elements of weather: rain, wind, fog, ice and snow affect the operation and flight of an airplane. In this program, NASA and FAA researchers will introduce students to math, science, and weather; demonstrate how these elements influence flight; and show how NASA and FAA research is used to limit the effects of these elements on flight. Students will examine: the tools, techniques, and technologies used by engineers and scientists to detect these and other climatological factors affecting aircraft in flight. The lesson and classroom experiment will involve students in the scientific process and emphasizing problem solving, measurement, and reasoning skills.

  1. NASA Connect: 'Plane Weather'

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Excerpt from the NASA Connect show 'Plane Weather' This clip explains what high and low pressure weather systems are, and how these affect weather patterns. Weather affects our daily lives. The elements of weather: rain, wind, fog, ice and snow affect the operation and flight of an airplane. In this program, NASA and FAA researchers will introduce students to math, science, and weather; demonstrate how these elements influence flight; and show how NASA and FAA research is used to limit the effects of these elements on flight. Students will examine: the tools, techniques, and technologies used by engineers and scientists to detect these and other climatological factors affecting aircraft in flight. The lesson and classroom experiment will involve students in the scientific process and emphasizing problem solving, measurement, and reasoning skills.

  2. Rational Prescription for a Dermatologist

    PubMed Central

    Prakash, Bhanu; Nadig, Prathiba; Nayak, Amitha

    2016-01-01

    The ultimate goal in dermatological therapy is to use the safest and least number of drugs in order to obtain the best possible effect in the shortest period and at reasonable cost. Rational drug use (RDU) is conventionally defined as the use of an appropriate, efficacious, safe and cost-effective drug given for the right indications in the right dose and formulation, at right time intervals. WHO estimates that more than half of all medicines are prescribed, dispensed or sold inappropriately, and that half of all patients fail to take them correctly as prescribed by the doctor. The process of Rational prescription for a Dermatologist (RPD) involves a series of steps such as defining the patient's illness, specifying the treatment objectives, using the principle of P-treatment, starting the treatment, providing appropriate information and monitoring the treatment. Reasons for irrational prescription could be physician related, patient related, industry related, regulations related. Practicing medicine irrationally can lead to disastrous events like increased morbidity and mortality, drain of resources, drug resistance etc. Principles to enhance the RDU in our practice and minimize errors of prescription are discussed in detail in this article. PMID:26955092

  3. Curve Stitching in LOGO.

    ERIC Educational Resources Information Center

    Muscat, Jean-Paul

    1992-01-01

    Uses LOGO to enhance the applicability of curve stitching in the mathematics curriculum. Presents the formulas and computer programs for the construction of parabolas, concentric circles, and epicycloids. Diagrams of constructed figures are provided. (MDH)

  4. Highly curved microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Cully, S.; Warren, J.; Gaines, G. A.; Priedhorsky, W.; Bloch, J.

    1990-01-01

    Several spherically curved microchannel plate (MCP) stack configurations were studied as part of an ongoing astrophysical detector development program, and as part of the development of the ALEXIS satellite payload. MCP pairs with surface radii of curvature as small as 7 cm, and diameters up to 46 mm have been evaluated. The experiments show that the gain (greater than 1.5 x 10 exp 7) and background characteristics (about 0.5 events/sq cm per sec) of highly curved MCP stacks are in general equivalent to the performance achieved with flat MCP stacks of similar configuration. However, gain variations across the curved MCP's due to variations in the channel length to diameter ratio are observed. The overall pulse height distribution of a highly curved surface MCP stack (greater than 50 percent FWHM) is thus broader than its flat counterpart (less than 30 percent). Preconditioning of curved MCP stacks gives comparable results to flat MCP stacks, but it also decreases the overall gain variations. Flat fields of curved MCP stacks have the same general characteristics as flat MCP stacks.

  5. Dynamics of dislocations described as evolving curves interacting with obstacles

    NASA Astrophysics Data System (ADS)

    Pauš, Petr; Beneš, Michal; Kolář, Miroslav; Kratochvíl, Jan

    2016-03-01

    In this paper we describe the model of glide dislocation interaction with obstacles based on the planar curve dynamics. The dislocations are represented as smooth curves evolving in a slip plane according to the mean curvature motion law, and are mathematically described by the parametric approach. We enhance the parametric model by employing so called tangential redistribution of curve points to increase the stability during numerical computation. We developed additional algorithms for topological changes (i.e. merging and splitting of dislocation curves) enabling a detailed modelling of dislocation interaction with obstacles. The evolving dislocations are approximated as a moving piece-wise linear curves. The obstacles are represented as idealized circular areas of a repulsive stress. Our model is numerically solved by means of semi-implicit flowing finite volume method. We present results of qualitative and quantitative computational studies where we demonstrate the topological changes and discuss the effect of tangential redistribution of curve points on computational results.

  6. Decision making: rational or hedonic?

    PubMed Central

    Cabanac, Michel; Bonniot-Cabanac, Marie-Claude

    2007-01-01

    Three experiments studied the hedonicity of decision making. Participants rated their pleasure/displeasure while reading item-sentences describing political and social problems followed by different decisions (Questionnaire 1). Questionnaire 2 was multiple-choice, grouping the items from Questionnaire 1. In Experiment 1, participants answered Questionnaire 2 rapidly or slowly. Both groups selected what they had rated as pleasant, but the 'leisurely' group maximized pleasure less. In Experiment 2, participants selected the most rational responses. The selected behaviors were pleasant but less than spontaneous behaviors. In Experiment 3, Questionnaire 2 was presented once with items grouped by theme, and once with items shuffled. Participants maximized the pleasure of their decisions, but the items selected on Questionnaires 2 were different when presented in different order. All groups maximized pleasure equally in their decisions. These results support that decisions are made predominantly in the hedonic dimension of consciousness. PMID:17848195

  7. Rational design of helical architectures

    PubMed Central

    Chakrabarti, Dwaipayan; Fejer, Szilard N.; Wales, David J.

    2009-01-01

    Nature has mastered the art of creating complex structures through self-assembly of simpler building blocks. Adapting such a bottom-up view provides a potential route to the fabrication of novel materials. However, this approach suffers from the lack of a sufficiently detailed understanding of the noncovalent forces that hold the self-assembled structures together. Here we demonstrate that nature can indeed guide us, as we explore routes to helicity with achiral building blocks driven by the interplay between two competing length scales for the interactions, as in DNA. By characterizing global minima for clusters, we illustrate several realizations of helical architecture, the simplest one involving ellipsoids of revolution as building blocks. In particular, we show that axially symmetric soft discoids can self-assemble into helical columnar arrangements. Understanding the molecular origin of such spatial organisation has important implications for the rational design of materials with useful optoelectronic applications.

  8. Max Weber's Types of Rationality: Cornerstones for the Analysis of Rationalization Processes in History.

    ERIC Educational Resources Information Center

    Kalberg, Stephen

    1980-01-01

    Explores rationality in Max Weber's works and identifies four types of rationality which play major roles in his writing--practical, theoretical, substantive, and formal. Implications for society and education are discussed. (DB)

  9. Plane Mercury librations

    NASA Astrophysics Data System (ADS)

    Barkin, Yu. V.; Ferrandiz, J. M.

    2009-04-01

    theory of Mercury librations in longitude by using three characteristics of Mercury rotation determined in the paper [3]. Two from these parameters are values of angle of librations in longitude and angular velocity in moment of passage of perihelion of Mercury orbit on 17 April 2002: (^g)0 = 0007 ± 0001, (^?•? )0 = (2.10± 0.06)•? ars/d. Third parameter determined in [3] is a dynamical coefficient: K = (B -A)•(4Cm ) = (5.08± 0.30) × 10-5. B > A are principal moment of inertia, corresponding to equatorial axes of inertia; Cm is a polar moment of inertia of the mantle of Mercury. 1 Analytical theory of plane Mercury librations. This theory describes forced and free librations of Mercury in longitude in the frame of plane problem about resonant librations of Mercury considered or as non-spherical rigid body, or as system of rigid non-spherical mantle and liquid ellipsoidal core. Saving the main terms for the perturbations of angle of librations ^g and angular velocity ^? in both mentioned cases we will have formulae [6]: ^g = K(E sin M + E sin2M + E sin 3M + E sin4M + E sin5M ) 1 2 3 4 5+K0 sin(E šKM- - φ) (A)

  10. The Rationality of Alcoholics Anonymous and the Spirituality of Rational Emotive Behavior Therapy.

    ERIC Educational Resources Information Center

    Velten, Emmett

    1996-01-01

    Argues that Alcoholics Anonymous (AA) and Rational Emotive Behavior Therapy (REBT) share important rational objectives and numerous cognitive-behavioral methods. Both emphasize a philosophical shift as a principal ingredient for change. Provides definitions of rationality and spirituality and explains how REBT and smart recovery are spiritual…

  11. IGMtransmission: Transmission curve computation

    NASA Astrophysics Data System (ADS)

    Harrison, Christopher M.; Meiksin, Avery; Stock, David

    2015-04-01

    IGMtransmission is a Java graphical user interface that implements Monte Carlo simulations to compute the corrections to colors of high-redshift galaxies due to intergalactic attenuation based on current models of the Intergalactic Medium. The effects of absorption due to neutral hydrogen are considered, with particular attention to the stochastic effects of Lyman Limit Systems. Attenuation curves are produced, as well as colors for a wide range of filter responses and model galaxy spectra. Photometric filters are included for the Hubble Space Telescope, the Keck telescope, the Mt. Palomar 200-inch, the SUBARU telescope and UKIRT; alternative filter response curves and spectra may be readily uploaded.

  12. Kummer surfaces associated with Seiberg-Witten curves

    NASA Astrophysics Data System (ADS)

    Malmendier, Andreas

    2012-01-01

    By carrying out a rational transformation on the base curve C of the Seiberg-Witten curve for N=2 supersymmetric pure SU(2)-gauge theory, we obtain a family of Jacobian elliptic K3 surfaces of Picard rank 17. The isogeny relating the Seiberg-Witten curve for pure SU(2)-gauge theory to the one for SU(2)-gauge theory with Nf=2 massless hypermultiplets extends to define a Nikulin involution on each K3 surface in the family. We show that the desingularization of the quotient of the K3 surface by the involution is isomorphic to a Kummer surface of the Jacobian variety of a curve of genus two. We then derive a relation between the Yukawa coupling associated with the elliptic K3 surface and the Yukawa coupling of pure SU(2)-gauge theory.

  13. Are Grade Expectations Rational? A Classroom Experiment

    ERIC Educational Resources Information Center

    Hossain, Belayet; Tsigaris, Panagiotis

    2015-01-01

    This study examines students' expectations about their final grade. An attempt is made to determine whether students form expectations rationally. Expectations in economics, rational or otherwise, carry valuable information and have important implications in terms of both teaching effectiveness and the role of grades as an incentive structure…

  14. The Emotional and Moral Basis of Rationality

    ERIC Educational Resources Information Center

    Boostrom, Robert

    2013-01-01

    This chapter explores the basis of rationality, arguing that critical thinking tends to be taught in schools as a set of skills because of the failure to recognize that choosing to think critically depends on the prior development of stable sentiments or moral habits that nourish a rational self. Primary among these stable sentiments are the…

  15. Developing Critical Rationality as a Pedagogical Aim

    ERIC Educational Resources Information Center

    Winch, Christopher

    2004-01-01

    The development of a conception of critical pedagogy is itself an aspect of the development of critical rationality within late modern societies, closely connected with the role of education in developing critical rationality. The role of critique pervades all aspects of life: for people as citizens, workers and self-determining private…

  16. Decision Making: Rational, Nonrational, and Irrational.

    ERIC Educational Resources Information Center

    Simon, Herbert A.

    1993-01-01

    Describes the current state of knowledge about human decision-making and problem-solving processes, explaining recent developments and their implications for management and management training. Rational goal-setting is the key to effective decision making and accomplishment. Bounded rationality is a realistic orientation, because the world is too…

  17. Rationality and Belief in Learning Mathematics

    ERIC Educational Resources Information Center

    Brown, Tony

    2016-01-01

    This paper argues that rationality and belief are mutually formative dimensions of school mathematics, where each term is more politically embedded than often depicted in the field of mathematics education research. School mathematics then presents not so much rational mathematical thought distorted by irrational beliefs but rather a particular…

  18. Professionalization in a Rationally Managed Corporate Organization.

    ERIC Educational Resources Information Center

    Alie, Raymond E.

    1982-01-01

    Explored the relationship of professionalization and rational corporate management. Subjects were 320 engineers in a merged manufacturing firm. Results indicated a relationship between graduate degree activity and organization membership, and confirmed that engineers exhibit greater professionalization in a rationally managed organization. (WAS)

  19. Fiber sources for complete calf starter rations.

    PubMed

    Murdock, F R; Wallenius, R W

    1980-11-01

    Complete calf starter rations containing either 1) alfalfa hay, 2) cottonseed hulls, or 3) alfalfa-beet pulp as sources of fiber were fed to Holstein heifer calves at two locations on a limited milk program from 3 days to 12 wk of age. Rations were isonitrogenous and similar in content of crude fiber and acid detergent fiber. Although growth and development were normal on all rations, calves fed the cottonseed hull ration consumed more starter and gained more body weight than calves fed the other sources of fiber. The similarity of feed efficiencies, rumen pH, and molar ratios of volatile fatty acids between rations indicated no appreciable differences in rumen development or function. The growth response of calves fed the cottonseed hull ration appeared to be a result of better ration acceptability for which no reason was evident. Calves raised at Puyallup gained more body weight than calves at Pullman, and these gains were made more efficiently. These location effects may be related to seasonal differences and greater demands for production of body heat. Although the incidence of scours was less for calves fed alfalfa hay starter, the incidence and severity of bloat were higher for that ration. PMID:6255021

  20. On rational integrals of geodesic flows

    NASA Astrophysics Data System (ADS)

    Kozlov, Valery V.

    2014-11-01

    This paper is concerned with the problem of first integrals of the equations of geodesics on two-dimensional surfaces that are rational in the velocities (or momenta). The existence of nontrivial rational integrals with given values of the degrees of the numerator and the denominator is proved using the Cauchy-Kovalevskaya theorem.

  1. Neurophysiology and Rationality in Political Thinking.

    ERIC Educational Resources Information Center

    Peterson, Steven A.

    Research both in cognitive psychology and psychobiology suggests that political behavior is often less rational than individuals believe it to be. Information processing, memory, and decision making are interlinked processes. Studies in cognitive psychology reveal that even though decision making requires rationality, individuals often adopt…

  2. The extended polar writhe: a tool for open curves mechanics

    NASA Astrophysics Data System (ADS)

    Prior, Christopher B.; Neukirch, Sébastien

    2016-05-01

    A measure of the writhing of a curve is introduced and is used to extend the Călugăreanu decomposition for closed curves, as well as the polar decomposition for curves bound between planes. The new writhe measure is also shown to be able to assess changes in linking due to belt-trick and knotting type deformations, and further its utility is illustrated on examples taken from elastic rod parameter-continuation studies. Finally C++ and mathematica codes are made available and shown to be faster than existing algorithms for the numerical computation of the writhe.

  3. The Bacterial Growth Curve.

    ERIC Educational Resources Information Center

    Paulton, Richard J. L.

    1991-01-01

    A procedure that allows students to view an entire bacterial growth curve during a two- to three-hour student laboratory period is described. Observations of the lag phase, logarithmic phase, maximum stationary phase, and phase of decline are possible. A nonpathogenic, marine bacterium is used in the investigation. (KR)

  4. Textbook Factor Demand Curves.

    ERIC Educational Resources Information Center

    Davis, Joe C.

    1994-01-01

    Maintains that teachers and textbook graphics follow the same basic pattern in illustrating changes in demand curves when product prices increase. Asserts that the use of computer graphics will enable teachers to be more precise in their graphic presentation of price elasticity. (CFR)

  5. Invariant rotational curves in Sitnikov's Problem

    NASA Astrophysics Data System (ADS)

    Martinez Alfaro, J.; Chiralt, Cristina

    1993-04-01

    The Sitnikov's Problem is a restricted three-body problem of celestial mechanics depending on the eccentricity, e. The Hamiltonian, H(z, v, t, e), does not depend on t if e = 0 and we have an integrable system; if e is small the KAM Theory proves the existence of invariant rotational curves, IRC. For larger eccentricities, we show that there exist two complementary sequences of intervals of values of e that accumulate to the maximum admissible value of the eccentricity, 1, and such that, for one of the sequences IRC around a fixed point persist. Moreover, they shrink to the plane z = 0 as e tends to 1.

  6. Curve of Spee - from orthodontic perspective.

    PubMed

    Dhiman, Sushma

    2015-01-01

    The presence of a curve of Spee (COS) of variable depth is common finding in the occlusal arrangement and is sixth key of occlusion The understanding of COS in the field of orthodontics is very important as orthodontists deal with it in virtually every patient they treat. An excessive COS is a common form of malocclusion that may be addressed in many ways, including posterior extrusion, anterior intrusion, and incisor proclination. The specific approach to leveling of COS should be selected based on each patient's needs. Soft tissue, crown-gingival relations, occlusal plane, and skeletofacial concerns are among the special considerations for treatment planning for leveling of COS. PMID:26752075

  7. A theory for turbulent curved wall jets

    NASA Technical Reports Server (NTRS)

    Roberts, Leonard

    1986-01-01

    A simple theoretical model is proposed to describe the flow of a turbulent wall jet along a curved surface into a quiescent atmosphere. An integral method is used to solve the momentum equation and identifies three contributions to the spreading rate of the wall jet: (1) turbulent diffusion in the wall jet; (2) wall curvature; and (3) rate of change of wall curvature. Closed from approximate solutions are found for the case of a plane wall, a circular cylinder, and a logarithmic spiral surface. Comparison with experimental data for these three cases is made showing good agreement.

  8. Curve of Spee - from orthodontic perspective

    PubMed Central

    Dhiman, Sushma

    2015-01-01

    The presence of a curve of Spee (COS) of variable depth is common finding in the occlusal arrangement and is sixth key of occlusion The understanding of COS in the field of orthodontics is very important as orthodontists deal with it in virtually every patient they treat. An excessive COS is a common form of malocclusion that may be addressed in many ways, including posterior extrusion, anterior intrusion, and incisor proclination. The specific approach to leveling of COS should be selected based on each patient's needs. Soft tissue, crown–gingival relations, occlusal plane, and skeletofacial concerns are among the special considerations for treatment planning for leveling of COS. PMID:26752075

  9. Approaches towards rational antiviral chemotherapy.

    PubMed Central

    Oxford, J. S.

    1979-01-01

    Present epidemic influenza is uncontrolled by immuno- or chemoprophylaxis. Mutants of varying antigenic composition arise with relatively high frequency in nature and are able to circumvent herd, or induced, immunity. Also, drug-resistant viruses can be selected in vitro and this resistance can be exchanged to other viruses by gene reassortment. Combined immuno- and chemoprophylaxis may provide a more effective approach to the ultimate control of the disease. Most antiviral compounds have been selected by random screening in the laboratory. Application of more specific enzyme assays such as the virion-associated RNA transcriptase assays may produce other compounds with a defined mode of action - semi-rational chemotherapy. RNA and polypeptide sequence studies are in progress elsewhere to define transcription and translation initiation sites or virus adsorption sites. Such knowledge could lead to a new generation of antiviral compounds. Specific delivery of virus inhibitory compounds is an interesting problem. Liposomes are lipid spheres, and these have been used for the delivery of antiviral compounds. Images Fig. 3a. Fig. 3b. Fig. 4 Fig. 5 PMID:461275

  10. Being 'rational' and being 'human': How National Health Service rationing decisions are constructed as rational by resource allocation panels.

    PubMed

    Russell, Jill; Greenhalgh, Trisha

    2014-09-01

    The English National Health Service Constitution states that patients have the right to expect all decisions about access to medicines and treatments to be made 'rationally'. Rationality in health care can be framed as instrumental, institutional or practical. In this article, we present a case example from an ethnographic study of the work of 'Individual Funding Request' panels to explore how rationality is enacted and accounted for in deliberations about the rationing of health care in the National Health Service. Our rhetorical analysis highlights how an embodied, practical rationality emerges as a significant aspect of rationality in practice, but at the same time has a problematic status in formal accounts of decision-making. We suggest that being both 'human' and 'rational' is a 'delicate balance' and creates a dilemma for Individual Funding Request panels. Aristotle's notion of phronesis provides a useful lens for theorising our observation of panel deliberations, and we argue for greater attention to the value of narrative ethics in helping us understand the challenges faced by resource allocators. PMID:24287296

  11. Curved butterfly bileaflet prosthetic cardiac valve

    SciTech Connect

    McQueen, D.M.; Peskin, C.S.

    1991-06-25

    An annular valve body having a central passageway for the flow of blood with two curved leaflets is described. Each of the leaflets is pivotally supported on an accentric positioned axis in the central passageway for moving between a closed position and an open position. The leaflets are curved in a plane normal to the eccentric axis and positioned with the convex side of the leaflets facing each other when the leaflets are in the open position. Various parameters such as the curvature of the leaflets, the location of the eccentric axis, and the maximum opening angle of the leaflets are optimized according to the following performance criteria: maximize the minimum peak velocity through the valve, maximize the net stroke volume, and minimize the mean forward pressure difference, thereby reducing thrombosis and improving the hemodynamic performance. 26 figures.

  12. Curved butterfly bileaflet prosthetic cardiac valve

    DOEpatents

    McQueen, David M.; Peskin, Charles S.

    1991-06-25

    An annular valve body having a central passageway for the flow of blood therethrough with two curved leaflets each of which is pivotally supported on an accentric positioned axis in the central passageway for moving between a closed position and an open position. The leaflets are curved in a plane normal to the eccentric axis and positioned with the convex side of the leaflets facing each other when the leaflets are in the open position. Various parameters such as the curvature of the leaflets, the location of the eccentric axis, and the maximum opening angle of the leaflets are optimized according to the following performance criteria: maximize the minimum peak velocity through the valve, maximize the net stroke volume, and minimize the mean forward pressure difference, thereby reducing thrombosis and improving the hemodynamic performance.

  13. Strong imploding shock - The representative curve

    NASA Astrophysics Data System (ADS)

    Mishkin, E. A.; Alejaldre, C.

    1981-02-01

    The representative curve of the ideal gas behind the front of a spherically or cylindrically asymmetric strong imploding shock is derived. The partial differential equations of mass, momentum and energy conservation are reduced to a set of ordinary differential equations by the method of quasi-separation of variables, following which the reduced pressure and density as functions of the radius with respect to the shock front are explicit functions of coordinates defining the phase plane of the self-similar solution. The curve in phase space representing the state of the imploded gas behind the shock front is shown to pass through the point where the reduced pressure is maximum, which is located somewhat behind the shock front and ahead of the tail of the shock.

  14. On the equivariant algebraic Jacobian for curves of genus two

    NASA Astrophysics Data System (ADS)

    Athorne, Chris

    2012-04-01

    We present a treatment of the algebraic description of the Jacobian of a generic genus two plane curve which exploits an SL2(k) equivariance and clarifies the structure of Flynn's 72 defining quadratic relations. The treatment is also applied to the Kummer variety.

  15. Sibling Curves 3: Imaginary Siblings and Tracing Complex Roots

    ERIC Educational Resources Information Center

    Harding, Ansie; Engelbrecht, Johann

    2009-01-01

    Visualizing complex roots of a quadratic equation has been a quest since the inception of the Argand plane in the 1800s. Many algebraic and numerical methods exist for calculating complex roots of an equation, but few visual methods exist. Following on from papers by Harding and Engelbrecht (A. Harding and J. Engelbrecht, "Sibling curves and…

  16. Pleats in crystals on curved surfaces.

    PubMed

    Irvine, William T M; Vitelli, Vincenzo; Chaikin, Paul M

    2010-12-16

    Hexagons can easily tile a flat surface, but not a curved one. Introducing heptagons and pentagons (defects with topological charge) makes it easier to tile curved surfaces; for example, soccer balls based on the geodesic domes of Buckminster Fuller have exactly 12 pentagons (positive charges). Interacting particles that invariably form hexagonal crystals on a plane exhibit fascinating scarred defect patterns on a sphere. Here we show that, for more general curved surfaces, curvature may be relaxed by pleats: uncharged lines of dislocations (topological dipoles) that vanish on the surface and play the same role as fabric pleats. We experimentally investigate crystal order on surfaces with spatially varying positive and negative curvature. On cylindrical capillary bridges, stretched to produce negative curvature, we observe a sequence of transitions-consistent with our energetic calculations-from no defects to isolated dislocations, which subsequently proliferate and organize into pleats; finally, scars and isolated heptagons (previously unseen) appear. This fine control of crystal order with curvature will enable explorations of general theories of defects in curved spaces. From a practical viewpoint, it may be possible to engineer structures with curvature (such as waisted nanotubes and vaulted architecture) and to develop novel methods for soft lithography and directed self-assembly. PMID:21164482

  17. Design of large aperture focal plane shutter

    NASA Astrophysics Data System (ADS)

    Hu, Jia-wen; Ma, Wen-li; Huang, Jin-long

    2012-09-01

    To satisfy the requirement of large telescope, a large aperture focal plane shutter with aperture size of φ200mm was researched and designed to realize, which could be started and stopped in a relative short time with precise position, and also the blades could open and close at the same time at any orientation. Timing-belts and stepper motors were adopted as the drive mechanism. Velocity and position of the stepper motors were controlled by the PWM pulse generated by DSP. Exponential curve is applied to control the velocity of the stepper motors to make the shutter start and stop in a short time. The closing/open time of shutter is 0.2s, which meets the performance requirements of large telescope properly.

  18. Traffic noise and the hyperbolic plane

    SciTech Connect

    Gibbons, G.W. Warnick, C.M.

    2010-04-15

    We consider the problem of sound propagation in a wind. We note that the rays, as in the absence of a wind, are given by Fermat's principle and show how to map them to the trajectories of a charged particle moving in a magnetic field on a curved space. For the specific case of sound propagating in a stratified atmosphere with a small wind speed, we show that the corresponding particle moves in a constant magnetic field on the hyperbolic plane. In this way, we give a simple 'straightedge and compass' method to estimate the intensity of sound upwind and downwind. We construct Mach envelopes for moving sources. Finally, we relate the problem to that of finding null geodesics in a squashed anti-de Sitter spacetime and discuss the SO(3,1)xR symmetry of the problem from this point of view.

  19. Factorization with genus 2 curves

    NASA Astrophysics Data System (ADS)

    Cosset, Romain

    2010-04-01

    The elliptic curve method (ECM) is one of the best factorization methods available. It is possible to use hyperelliptic curves instead of elliptic curves but it is in theory slower. We use special hyperelliptic curves and Kummer surfaces to reduce the complexity of the algorithm. Our implementation GMP-HECM is faster than GMP-ECM for factoring large numbers.

  20. [The rational diagnostic of cholangiocarcinoma].

    PubMed

    Rydlo, Martin; Dvořáčková, Jana; Kupka, Tomáš; Klvaňa, Pavel; Havelka, Jaroslav; Uvírová, Magdalena; Geryk, Edvard; Czerný, Daniel; Jonszta, Tomáš; Bojková, Martina; Hrabovský, Vladimír; Jelínková, Veronika; Martínek, Arnošt; Dítě, Petr

    2016-02-01

    Cholangiocarcinoma (CC) is a rare malignant tumour arising from cholangiocytes, and its prognosis is usually unfavourable, mostly as a result of late diagnosis of the tumour. The current incidence of cholangiocarcinoma in the Czech Republic is 1.4/100,000 inhabitants per year; in less than 30 % of patients with CC, one of the known risk factors can be identified, most frequently, primary sclerosing cholangitis. Only patients with early diagnosed and surgically amenable cholangiocarcinoma are likely to have a longer survival time; in their case, survival for more than five years has been achieved in 20 % to 40 %. From the perspective of the need for early diagnosis of CC, a significant part is played by imaging and histopathologic evaluation; the early diagnostic significance of oncomarkers is limited. The rational early diagnosis of CC consists in effective use of differentiated advantages of different imaging modalities - MRI with DSA appears to be the optimal method, endosonography is a sensitive method for the identification of malignancy in the hepatic hilum or distal common bile duct, MRCP (magnetic resonance cholangiopancreatography) is used to display pathological changes in the biliary tree, ERCP (endoscopic retrograde cholangiopancreatography) allows material removal for histopathological examination. Other new approaches are also beneficial, such as IDUS - intraductal ultrasonography of biliary tract or SPY-GLASS, enabling examination of the bile ducts by direct view with the possibility of taking targeted biopsies. Sensitivity and specificity of histology and cytology can be increased by using the molecular cytogenetic FISH method, i.e. fluorescence in situ by hybridization, with a specificity of 97 %. PMID:27172439

  1. Atlas of fatigue curves

    SciTech Connect

    Boyer, H.E.

    1986-01-01

    This Atlas was developed to serve engineers who are looking for fatigue data on a particular metal or alloy. Having these curves compiled in a single book will also facilitate the computerization of the involved data. It is pointed out that plans are under way to make the data in this book available in ASCII files for analysis by computer programs. S-N curves which typify effects of major variables are considered along with low-carbon steels, medium-carbon steels, alloy steels, HSLA steels, high-strength alloy steels, heat-resisting steels, stainless steels, maraging steels, cast irons, and heat-resisting alloys. Attention is also given to aluminum alloys, copper alloys, magnesium alloys, molybdenum, tin alloys, titanium and titanium alloys, zirconium, steel castings, closed-die forgings, powder metallurgy parts, composites, effects of surface treatments, and test results for component parts.

  2. Spinal curves and scoliosis.

    PubMed

    Anderson, Susan M

    2007-01-01

    Scoliosis, an abnormal side-to-side curve of the spine with associated vertebral rotation, affects as many as 4% of all adolescents. Several different categories of scoliosis exist, and treatment can range from observation and follow-up to bracing and surgical correction. This article discusses special imaging series for scoliosis and emphasizes the need for proper radiation protection techniques for patients with scoliosis, most of whom are girls in their early to mid-teens. PMID:17848532

  3. Mouse Curve Biometrics

    SciTech Connect

    Schulz, Douglas A.

    2007-10-08

    A biometric system suitable for validating user identity using only mouse movements and no specialized equipment is presented. Mouse curves (mouse movements with little or no pause between them) are individually classied and used to develop classication histograms, which are representative of an individual's typical mouse use. These classication histograms can then be compared to validate identity. This classication approach is suitable for providing continuous identity validation during an entire user session.

  4. Modeling magnetization curves in magnetic thin films with striped patterns

    NASA Astrophysics Data System (ADS)

    Di Pietro Martínez, M.; Milano, J.; Eddrief, M.; Marangolo, M.; Bustingorry, S.

    2016-04-01

    In this work, we study magnetic thin films presenting magnetic stripe patterns. A fingerprint of such domains is a linear behavior of the in-plane magnetization curves below a given saturation field. We present free energy models for the in-plane magnetization curves which permit us to extract key geometrical information about the stripe patterns, such as the maximum canted angle of the magnetization and the domain wall width. As an example, we discuss in this work magnetization curves for Fe1-x Ga x magnetic films which present a stripe pattern with a period of 160 nm and we found a typical maximum canted angle of {{85}{^\\circ}} and a domain wall width around 30 nm.

  5. The Stephan Curve revisited.

    PubMed

    Bowen, William H

    2013-01-01

    The Stephan Curve has played a dominant role in caries research over the past several decades. What is so remarkable about the Stephan Curve is the plethora of interactions it illustrates and yet acid production remains the dominant focus. Using sophisticated technology, it is possible to measure pH changes in plaque; however, these observations may carry a false sense of accuracy. Recent observations have shown that there may be multiple pH values within the plaque matrix, thus emphasizing the importance of the milieu within which acid is formed. Although acid production is indeed the immediate proximate cause of tooth dissolution, the influence of alkali production within plaque has received relative scant attention. Excessive reliance on Stephan Curve leads to describing foods as "safe" if they do not lower the pH below the so-called "critical pH" at which point it is postulated enamel dissolves. Acid production is just one of many biological processes that occur within plaque when exposed to sugar. Exploration of methods to enhance alkali production could produce rich research dividends. PMID:23224410

  6. Ankle moment generation and maximum-effort curved sprinting performance.

    PubMed

    Luo, Geng; Stefanyshyn, Darren

    2012-11-15

    Turning at high speed along acute curves is crucial for athletic performance. One determinant of curved sprinting speed is the ground reaction force that can be created by the supporting limb; the moment generated at the ankle joint may influence such force generation. Body lean associated with curved sprints positions the ankle joints in extreme in-/eversion, and may hinder the ankle moment generation. To examine the influence of ankle moment generation on curved sprinting performance, 17 male subjects performed maximum-effort curved sprints in footwear with and without a wedge. The wedged footwear was constructed with the intention to align the ankle joints closer to their neutral frontal-plane configuration during counter-clockwise curved sprints so greater joint moments might be generated. We found, with the wedged footwear, the average eversion angle of the inside leg ankle was reduced, and the plantarflexion moment generation increased significantly. Meanwhile, the knee extension moment remained unchanged. With the wedged footwear, stance-average centripetal ground reaction force increased significantly while no difference in the vertical ground reaction force was detected. The subjects created a greater centripetal ground reaction impulse in the wedged footwear despite a shortened stance phase when compared to the control. Stance-average curved sprinting speed improved by 4.3% with the wedged footwear. The changes in ankle moment and curved sprinting speed observed in the current study supports the notion that the moment generation at the ankle joint may be a performance constraint for curved sprinting. PMID:23022207

  7. Rationing of health care: is there an economic rationality to it?

    PubMed

    Zweifel, Peter

    2015-11-01

    The point of departure of this Editorial is the fact that we all are engaged in self-rationing in our everyday lives. We would like to spend more money on all sorts of nice things and devote more time to our cherished activities. Imposed rationing is characteristic of wartime governments, who seek to prevent the rich from gobbling up the resources left by the army. Since the publication in 1987 of David Callahan's Setting Limits: Medical Goals in an Aging Society (Callahan, Setting limits: medical goals in an aging society, Simon & Schuster, New York, 1987), rationing of health care has become a widely debated issue (the Internet is full of pertinent entries). While rationing has also been addressed by health economists, there are three puzzling observations. First, Callahan (Callahan, Setting limits: medical goals in an aging society, Simon & Schuster, New York, 1987) wrote for an American audience whereas rationing was introduced by the British National Health Service (NHS) well before 1987, with little debate. Second, the economic theory of rationing had been laid out by James Tobin [Ectrica 20(4): 521-533, 1952] as early as 1952--but health economists seem to have neglected his groundwork when writing about rationing. Third, they accept government-imposed rationing as inevitable in the case of health care, as though the self-rationing alternative was unavailable. An attempt is made here to provide rational explanations for these puzzles. PMID:25847329

  8. Interactive visualizations of blowups of the plane.

    PubMed

    Schenzel, Peter; Stussak, Christian

    2013-06-01

    Blowups are an important technique in algebraic geometry that permit the smoothing of singular algebraic varieties. It is a challenge to visualize this process even in the case of blowups of points X in the affine plane AA(IR)(2). First results were obtained by Brodmann with the aid of the so-called toroidal blowup, a compact embedding of the blowup into affine 3-space. In fact, Brodmann provides a rational parametrization of the toroidal blowup, but its visualization fails in the neighborhood of X because the parametrization tends to indefinite terms of the form 0/0. Our approach is based on implicitization of the parametric form. By methods from commutative algebra we are able to reduce the implicitization to the computation of a single, fairly simple resultant. This provides an algebraic equation of the implicit surface of the toroidal blowup including the so-called exceptional fiber associated with X. Surprisingly, the degree of the equation grows only linearly with the degree of the parametrization. By applying additional clipping techniques to the implicit surface we are able to visualize the toroidal blowup as well as its deformations by several parameters interactively in real time using GPU-based ray casting techniques. The methods of the paper provide insights in the structure of blowups of points, even if the points are interactively moved or tend to degenerations. PMID:22802122

  9. Smarandache curves according to Sabban frame of fixed pole curve belonging to the Bertrand curves pair

    NASA Astrophysics Data System (ADS)

    Şenyurt, Süleyman; Altun, Yasin; Cevahir, Ceyda

    2016-04-01

    In this paper, we investigate the Smarandache curves according to Sabban frame of fixed pole curve which drawn by the unit Darboux vector of the Bertrand partner curve. Some results have been obtained. These results were expressed as the depends Bertrand curve.

  10. High speed curved position sensitive detector

    DOEpatents

    Hendricks, Robert W.; Wilson, Jack W.

    1989-01-01

    A high speed curved position sensitive porportional counter detector for use in x-ray diffraction, the detection of 5-20 keV photons and the like. The detector employs a planar anode assembly of a plurality of parallel metallic wires. This anode assembly is supported between two cathode planes, with at least one of these cathode planes having a serpentine resistive path in the form of a meander having legs generally perpendicular to the anode wires. This meander is produced by special microelectronic fabrication techniques whereby the meander "wire" fans outwardly at the cathode ends to produce the curved aspect of the detector, and the legs of the meander are small in cross-section and very closely spaced whereby a spatial resolution of about 50 .mu.m can be achieved. All of the other performance characteristics are about as good or better than conventional position sensitive proportional counter type detectors. Count rates of up to 40,000 counts per second with 0.5 .mu.s shaping time constants are achieved.

  11. Determining the pivotal plane of fluid lipid membranes in simulations.

    PubMed

    Wang, Xin; Deserno, Markus

    2015-10-28

    Each leaflet of a curved lipid membrane contains a surface at which the area strain vanishes, the so-called pivotal plane. Its distance z0 from the bilayer's midplane arises in numerous contexts, for instance the connection between monolayer and bilayer moduli, stress-profile moments, or area-difference elasticity theories. Here, we propose two precise methods for determining the location of the pivotal plane in computer simulations, both of which rely on monitoring the lipid imbalance across a curved bilayer. The first method considers the ratio of lipid number between the two leaflets of cylindrical or spherical vesicles; it hence requires lipid flip-flop for equilibration. The second method looks at the leaflet difference across local sections cut out from a buckled membrane; this observable equilibrates even in the absence of flip-flop. We apply our methods to two different coarse-grained lipid models, the generic three-bead solvent-free Cooke model and a ten-bead representation of dimyristoylphosphocholine with the explicit solvent MARTINI model. The Cooke model is amenable to both methods and gives results that agree at the percent level. Using it, we also show that the pivotal plane moves outward as lipid curvature becomes more positive. The MARTINI model can only be analyzed with the buckling method; the obtained value z0 = 0.850(11) nm lies about 0.4 nm inwards of the glycerol backbone and is hence unexpectedly small. We attribute this to limitations of the coarse-grained description, suggesting that the location of the pivotal plane might be a good indicator for how well lipid models capture the microscopic origins of curvature elasticity. Finally, we also show that the pivotal plane position itself moves as the membrane is bent. The leading correction is linear in curvature, dependent on the Poisson ratio, and can matter when analyzing experimental results obtained from highly curved inverse hexagonal phases. PMID:26520500

  12. Determining the pivotal plane of fluid lipid membranes in simulations

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Deserno, Markus

    2015-10-01

    Each leaflet of a curved lipid membrane contains a surface at which the area strain vanishes, the so-called pivotal plane. Its distance z0 from the bilayer's midplane arises in numerous contexts, for instance the connection between monolayer and bilayer moduli, stress-profile moments, or area-difference elasticity theories. Here, we propose two precise methods for determining the location of the pivotal plane in computer simulations, both of which rely on monitoring the lipid imbalance across a curved bilayer. The first method considers the ratio of lipid number between the two leaflets of cylindrical or spherical vesicles; it hence requires lipid flip-flop for equilibration. The second method looks at the leaflet difference across local sections cut out from a buckled membrane; this observable equilibrates even in the absence of flip-flop. We apply our methods to two different coarse-grained lipid models, the generic three-bead solvent-free Cooke model and a ten-bead representation of dimyristoylphosphocholine with the explicit solvent MARTINI model. The Cooke model is amenable to both methods and gives results that agree at the percent level. Using it, we also show that the pivotal plane moves outward as lipid curvature becomes more positive. The MARTINI model can only be analyzed with the buckling method; the obtained value z0 = 0.850(11) nm lies about 0.4 nm inwards of the glycerol backbone and is hence unexpectedly small. We attribute this to limitations of the coarse-grained description, suggesting that the location of the pivotal plane might be a good indicator for how well lipid models capture the microscopic origins of curvature elasticity. Finally, we also show that the pivotal plane position itself moves as the membrane is bent. The leading correction is linear in curvature, dependent on the Poisson ratio, and can matter when analyzing experimental results obtained from highly curved inverse hexagonal phases.

  13. Orthogonal rational functions and tridiagonal matrices

    NASA Astrophysics Data System (ADS)

    Bultheel, A.; González-Vera, P.; Hendriksen, E.; Njåstad, O.

    2003-04-01

    We study the recurrence relation for rational functions whose poles are in a prescribed sequence of numbers that are real or infinite and that are orthogonal with respect to an Hermitian positive linear functional. We especially discuss the interplay between finite and infinite poles. The recurrence relation will also be described in terms of a tridiagonal matrix which is a generalization of the Jacobi. matrix of the polynomial situation which corresponds to placing all the poles at infinity. This matrix not only describes the recurrence relation, but it can be used to give a determinant expression for the orthogonal rational functions and it also allows for the formulation of a generalized eigenvalue problem whose eigenvalues are the zeros of an orthogonal rational function. These nodes can be used in rational Gauss-type quadrature formulas and the corresponding weights can be obtained from the first components of the corresponding eigenvectors.

  14. Rationality and allocating scarce medical resources.

    PubMed

    Forsberg, R P

    1995-02-01

    In an article titled, "Who Shall Live When Not All Can?", James Childress proposes a system for allocating scarce lifesaving medical resources based on random selection procedures. Childress writes of random selection procedures, [They] "cannot be dismissed as a 'non-rational' and 'non-human' ...without an inquiry into the reasons, including human values which might justify it." My thesis is that once we concentrate on determining the rationality of random selection procedures, we will see that Childress's claim that we cannot dismiss such procedures as 'non-rational' is open to question. My claim will be that while both random selection and social worth procedures are rationally defensible systems, random selection procedures easily lead to specific choices that are objectively irrational, apart from the limited perspective of the random selection process itself. PMID:7738457

  15. Skyrmions, rational maps, and scaling identities

    SciTech Connect

    Charalampidis, E. G.; Ioannidou, T. A.; Manton, N. S.

    2011-03-15

    Starting from approximate Skyrmion solutions obtained using the rational map ansatz, improved approximate Skyrmions are constructed using scaling arguments. Although the energy improvement is small, the change of shape clarifies whether the true Skyrmions are more oblate or prolate.

  16. Validation Testing of the Rational Behavior Inventory.

    ERIC Educational Resources Information Center

    Whiteman, Victor L.; Shorkey, Clayton T.

    1978-01-01

    The validity of the Rational Behavior Inventory was investigated by examining its relationship with four other measures of personality in addition to class standing and age. Results supported the validity of the measure. (JKS)

  17. Pandemic Ventilator Rationing and Appeals Processes

    PubMed Central

    Patrone, Daniel; Resnik, David

    2014-01-01

    In a severe influenza pandemic, hospitals will likely experience serious and widespread shortages of patient pulmonary ventilators and of staff qualified to operate them. Deciding who will receive access to mechanical ventilation will often determine who lives and who dies. This prospect raises an important question whether pandemic preparedness plans should include some process by which individuals affected by ventilator rationing would have the opportunity to appeal adverse decisions. However, the issue of appeals processes to ventilator rationing decisions has been largely neglected in state pandemic planning efforts. If we are to devise just and effective plans for coping with a severe influenza pandemic, more attention to the issue of appeals processes for pandemic ventilator rationing decisions is needed. Arguments for and against appeals processes are considered, and some suggestions are offered to help efforts at devising more rational pandemic preparedness plans. PMID:20354793

  18. A framework for rationing by clinical judgment.

    PubMed

    Hurst, Samia A; Danis, Marion

    2007-09-01

    Although rationing by clinical judgment is controversial, its acceptability partly depends on how it is practiced. In this paper, rationing by clinical judgment is defined in three different circumstances that represent increasingly wider circles of resource pools in which the rationing decision takes place: triage during acute shortage, comparison to other potential patients in a context of limited but not immediately strained resources, and determination of whether expected benefit of an intervention is deemed sufficient to warrant its cost by reference to published population based thresholds. Notions of procedural justice are applied along with an analytical framework of six minimal requisites in order to facilitate fair bedside rationing: (1) a closed system that offers reciprocity, (2) attention to general concerns of justice, (3) respect for individual variations, (4) application of a consistent process, (5) explicitness, and (6) review of decisions. The process could be monitored for its applicability and appropriateness. PMID:18210983

  19. Quantum Curves for Hitchin Fibrations and the Eynard-Orantin Theory

    NASA Astrophysics Data System (ADS)

    Dumitrescu, Olivia; Mulase, Motohico

    2014-06-01

    We generalize the topological recursion of Eynard-Orantin (JHEP 0612:053, 2006; Commun Number Theory Phys 1:347-452, 2007) to the family of spectral curves of Hitchin fibrations. A spectral curve in the topological recursion, which is defined to be a complex plane curve, is replaced with a generic curve in the cotangent bundle T* C of an arbitrary smooth base curve C. We then prove that these spectral curves are quantizable, using the new formalism. More precisely, we construct the canonical generators of the formal -deformation family of D modules over an arbitrary projective algebraic curve C of genus greater than 1, from the geometry of a prescribed family of smooth Hitchin spectral curves associated with the -character variety of the fundamental group π1( C). We show that the semi-classical limit through the WKB approximation of these -deformed D modules recovers the initial family of Hitchin spectral curves.

  20. Nanoindentation on the doubler plane of KDP single crystal

    NASA Astrophysics Data System (ADS)

    Xiaoguang, Guo; Xiaoji, Zhang; Xianzhao, Tang; Dongming, Guo; Hang, Gao; Xiaoji, Teng

    2013-03-01

    The nanohardness is from 1.44 to 2.61 GPa, the Vickers hardness is from 127 to 252 Vickers, and elastic modulus is from 52 to 123 GPa by the nanoindentation experiments on the doubler plane of KDP crystal. An indentation size effect is observed on the doubler plane in the test as the nanohardness and elastic modulus decreases with the increase of the maximum load. Slippage is identified as the major mode of plastic deformation, and pop-in events are attributed to the initiation of slippage. And the variation of unloading curve end is the result of stick effects between the indenter and the contact surface. The depth of the elastic deformation, which is between 40 and 75 nm, is responsible for the elastic deformation. The doubler plane of KDP crystal has anisotropy, and the relative anisotropy of nanohardness is 8.2% and the relative anisotropy of elastic modulus is 8.0%.

  1. Connectivity of Julia Sets for Singularly Perturbed Rational Maps

    NASA Astrophysics Data System (ADS)

    Devaney, Robert L.; Russell, Elizabeth D.

    2013-01-01

    In this paper we consider the family of rational maps of the form Fλ(z) = zn + λ/zn where n ≥ 2. It is known that there are two cases where the Julia sets of these maps are not connected. If the critical values of Fλ lie in the basin of ∞, then the Julia set is a Cantor set. And if the critical values lie in the preimage of the basin surrounding the pole at 0, then the Julia set is a Cantor set of concentric simple closed curves around the origin. We prove in this paper that, in all other cases, the Julia set of Fλ is a connected set.

  2. Intergroup Conflict and Rational Decision Making

    PubMed Central

    Martínez-Tur, Vicente; Peñarroja, Vicente; Serrano, Miguel A.; Hidalgo, Vanesa; Moliner, Carolina; Salvador, Alicia; Alacreu-Crespo, Adrián; Gracia, Esther; Molina, Agustín

    2014-01-01

    The literature has been relatively silent about post-conflict processes. However, understanding the way humans deal with post-conflict situations is a challenge in our societies. With this in mind, we focus the present study on the rationality of cooperative decision making after an intergroup conflict, i.e., the extent to which groups take advantage of post-conflict situations to obtain benefits from collaborating with the other group involved in the conflict. Based on dual-process theories of thinking and affect heuristic, we propose that intergroup conflict hinders the rationality of cooperative decision making. We also hypothesize that this rationality improves when groups are involved in an in-group deliberative discussion. Results of a laboratory experiment support the idea that intergroup conflict –associated with indicators of the activation of negative feelings (negative affect state and heart rate)– has a negative effect on the aforementioned rationality over time and on both group and individual decision making. Although intergroup conflict leads to sub-optimal decision making, rationality improves when groups and individuals subjected to intergroup conflict make decisions after an in-group deliberative discussion. Additionally, the increased rationality of the group decision making after the deliberative discussion is transferred to subsequent individual decision making. PMID:25461384

  3. The solar system's invariable plane

    NASA Astrophysics Data System (ADS)

    Souami, D.; Souchay, J.

    2012-07-01

    Context. The dynamics of solar system objects, such as dwarf planets and asteroids, has become a well-established field of celestial mechanics in the past thirty years, owing to the improvements that have been made in observational techniques and numerical studies. In general, the ecliptic is taken as the reference plane in these studies, although there is no dynamical reason for doing so. In contrast, the invariable plane as originally defined by Laplace, seems to be a far more natural choice. In this context, the latest study of this plane dates back to Burkhardt. Aims: We define and determine the orientation of the invariable plane of the solar system with respect to both the ICRF and the equinox-ecliptic of J2000.0, and evaluate the accuracy of our determination. Methods: Using the long-term numerical ephemerides DE405, DE406, and INPOP10a over their entire available time span, we computed the total angular momentum of the solar system, as well as the individual contribution to it made by each of the planets, the dwarf planets Pluto and Ceres, and the two asteroids Pallas and Vesta. We then deduced the orientation of the invariable plane from these ephemerides. Results: We update the previous results on the determination of the orientation of the invariable plane with more accurate data, and a more complete analysis of the problem, taking into account the effect of the dwarf planet (1) Ceres as well as two of the biggest asteroids, (4) Vesta and (2) Pallas. We show that the inclusion of these last three bodies significantly improves the accuracy of determination of the invariable plane, whose orientation over a 100 y interval does not vary more than 0.1 mas in inclination, and 0.3 mas in longitude of the ascending node. Moreover, we determine the individual contributions of each body to the total angular momentum of the solar system, as well as the inclination and longitude of the node with respect to this latter plane. Conclusions: Owing to the high accuracy

  4. Anterior Overgrowth in Primary Curves, Compensatory Curves and Junctional Segments in Adolescent Idiopathic Scoliosis

    PubMed Central

    van Stralen, Marijn; Chu, Winnie C. W.; Lam, Tsz-Ping; Ng, Bobby K. W.; Vincken, Koen L.; Cheng, Jack C. Y.; Castelein, René M.

    2016-01-01

    Introduction Although much attention has been given to the global three-dimensional aspect of adolescent idiopathic scoliosis (AIS), the accurate three-dimensional morphology of the primary and compensatory curves, as well as the intervening junctional segments, in the scoliotic spine has not been described before. Methods A unique series of 77 AIS patients with high-resolution CT scans of the spine, acquired for surgical planning purposes, were included and compared to 22 healthy controls. Non-idiopathic curves were excluded. Endplate segmentation and local longitudinal axis in endplate plane enabled semi-automatic geometric analysis of the complete three-dimensional morphology of the spine, taking inter-vertebral rotation, intra-vertebral torsion and coronal and sagittal tilt into account. Intraclass correlation coefficients for interobserver reliability were 0.98–1.00. Coronal deviation, axial rotation and the exact length discrepancies in the reconstructed sagittal plane, as defined per vertebra and disc, were analyzed for each primary and compensatory curve as well as for the junctional segments in-between. Results The anterior-posterior difference of spinal length, based on “true” anterior and posterior points on endplates, was +3.8% for thoracic and +9.4% for (thoraco)lumbar curves, while the junctional segments were almost straight. This differed significantly from control group thoracic kyphosis (-4.1%; P<0.001) and lumbar lordosis (+7.8%; P<0.001). For all primary as well as compensatory curves, we observed linear correlations between the coronal Cobb angle, axial rotation and the anterior-posterior length difference (r≥0.729 for thoracic curves; r≥0.485 for (thoraco)lumbar curves). Conclusions Excess anterior length of the spine in AIS has been described as a generalized growth disturbance, causing relative anterior spinal overgrowth. This study is the first to demonstrate that this anterior overgrowth is not a generalized phenomenon. It is

  5. Automatic location of microscopic focal planes for computerized stereology

    NASA Astrophysics Data System (ADS)

    Elozory, Daniel T.; Bonam, Om Pavithra; Kramer, Kurt; Goldgof, Dmitry B.; Hall, Lawrence O.; Mangual, Osvaldo; Mouton, Peter R.

    2011-03-01

    When applying design-based stereology to biological tissue, there are two primary applications for an auto-focusing function in the software of computerized stereology system. The system must first locate the in-focus optical planes at the upper and lower surfaces of stained tissue sections, thus identifying the top and bottom as well as the thickness of the tissue. Second, the system must find the start and end along the Z-axis of stained objects within a Z-stack of images through tissue sections. In contrast to traditional autofocus algorithms that seek a global maximum or peak on the focus curve, the goal of this study was to find the two "knees" of the focus curve that represent the "just out-of-focus" focal planes. The upper surface of the tissue section is defined as the image just before focus is detected moving down the Z-stack. Continuing down, the lower surface is defined as the first image of the last set of adjacent images where focus is no longer detected. The performance of seven focus algorithms in locating the top and bottom focal planes of tissue sections was analyzed by comparing each algorithm on 34 Z-stacks including a total of 828 images. The Thresholded Absolute Gradient algorithm outperformed all others, correctly identifying the top or bottom focal plane within an average of 1 μm on the training data as well as the test data.

  6. A program to compute EM scattering of plane wave by a perfectly conducting half-plane in a finitely conducting layered half-space

    NASA Astrophysics Data System (ADS)

    Caleb Dhanasekaran, P.; Poddar, M.

    A FORTRAN program utilizing an integral equation calculates 10 field quantities relating to the electromagnetic (EM) scattering of plane wave by a perfectly conducting half-plane buried in a finitely conducting layered half-space. The computing algorithm is executable on a computer of small storage capacity such as PDP 11/40 and as such is useful to many exploration scientists without the facility of a mainframe computer, for computing model curves to interpret field data.

  7. Navigating solid medical images by pencils of sectioning planes

    NASA Astrophysics Data System (ADS)

    Bookstein, Fred L.; Athey, Brian D.; Green, William D. K.; Wetzel, Arthur W.

    2000-10-01

    Beyond their involvement in ordinary surface rendering, the boundaries of organs in medical images have differential properties that make them quite useful for quantitative understanding. In particular, their geometry affords a framework for navigating the original solid, representing its R3 contents quite flexibility as multiple pseudovolumes R2 x T, where T is ar eal-valued parameter standing for screen time. A navigation is a smoothly parameterized series of image sections characterized by normal direction, centerpoint, scale and orientation. Such filmstrips represent a radical generalization of conventional medical image dynamics. The lances encountered in these navigations can be represented by constructs from classic differential geometry. Sequences of plane sections can be formalized as continuous pencils of planes, sets of cardinality (infinity) 1 that are sometimes explicitly characterized by a real-value parameter and sometimes defined implicitly as the intersection (curve of common elements) of a pair of bundles of (infinity) 2 planes. An example of the first type of navigation is the pencil of planes through the tangent line at one point of a curve; of the second type, the cone of planes through a point tangent to a surface. The further enhancements of centering, orienting, and rescaling in the medical context are intended to leave landmark points or boundary intersections invariant on the screen. Edgewarp, a publicly available software package, allows free play with pencils of planes like these as they section one single enormous medical data resource, the Visible Human data sets from the National Library of Medicine. This paper argues the relative merits of such visualizations over conventional surface-rendered flybys for understanding and communication of associated anatomical knowledge.

  8. When Is a Bernstein-bezier Curve the Graph of a Function?

    NASA Technical Reports Server (NTRS)

    Mclaughlin, H. W.

    1985-01-01

    The question of determining when a Bernstein-Bezier cubic curve in the plane can be represented as the graph of function in some fixed orthogonal coordinate system is considered. The notion of a curve being monotone in a given direction is introduced to aid in the analysis.

  9. The Characteristic Curves of Water

    NASA Astrophysics Data System (ADS)

    Neumaier, Arnold; Deiters, Ulrich K.

    2016-09-01

    In 1960, E. H. Brown defined a set of characteristic curves (also known as ideal curves) of pure fluids, along which some thermodynamic properties match those of an ideal gas. These curves are used for testing the extrapolation behaviour of equations of state. This work is revisited, and an elegant representation of the first-order characteristic curves as level curves of a master function is proposed. It is shown that Brown's postulate—that these curves are unique and dome-shaped in a double-logarithmic p, T representation—may fail for fluids exhibiting a density anomaly. A careful study of the Amagat curve (Joule inversion curve) generated from the IAPWS-95 reference equation of state for water reveals the existence of an additional branch.

  10. A heuristic for the distribution of point counts for random curves over a finite field

    PubMed Central

    Achter, Jeffrey D.; Erman, Daniel; Kedlaya, Kiran S.; Wood, Melanie Matchett; Zureick-Brown, David

    2015-01-01

    How many rational points are there on a random algebraic curve of large genus g over a given finite field ? We propose a heuristic for this question motivated by a (now proven) conjecture of Mumford on the cohomology of moduli spaces of curves; this heuristic suggests a Poisson distribution with mean q+1+1/(q−1). We prove a weaker version of this statement in which g and q tend to infinity, with q much larger than g. PMID:25802415

  11. Titration Curves: Fact and Fiction.

    ERIC Educational Resources Information Center

    Chamberlain, John

    1997-01-01

    Discusses ways in which datalogging equipment can enable titration curves to be measured accurately and how computing power can be used to predict the shape of curves. Highlights include sources of error, use of spreadsheets to generate titration curves, titration of a weak acid with a strong alkali, dibasic acids, weak acid and weak base, and…

  12. Explosive plane-wave lens

    DOEpatents

    Marsh, Stanley P.

    1988-01-01

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive.

  13. Explosive plane-wave lens

    DOEpatents

    Marsh, S.P.

    1988-03-08

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 4 figs.

  14. Explosive plane-wave lens

    DOEpatents

    Marsh, S.P.

    1987-03-12

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 3 figs., 3 tabs.

  15. Plane waves as tractor beams

    NASA Astrophysics Data System (ADS)

    Forgács, Péter; Lukács, Árpád; Romańczukiewicz, Tomasz

    2013-12-01

    It is shown that in a large class of systems, plane waves act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode carrying more momentum, in which case excess momentum is created behind the scatterer. This tractor beam or negative radiation pressure (NRP) effect, is found to be generic in systems with multiple scattering channels. In a birefringent medium, electromagnetic plane waves incident on a thin plate exert NRP of the same order of magnitude as optical radiation pressure, while in artificial dielectrics (metamaterials), the magnitude of NRP can even be macroscopic. In two dimensions, we study various scattering situations on vortices, and NRP is shown to occur by the scattering of heavy baryons into light leptons off cosmic strings, and by neutron scattering off vortices in the XY model.

  16. The Laplace Planes of Uranus and Pluto

    NASA Technical Reports Server (NTRS)

    Dobrovolskis, Anthony R.

    1993-01-01

    Satellite orbits close to an oblate planet precess about its equatorial plane, while distant satellites precess around the plane of the planet's heliocentric orbit. In between, satellites in nearly circular orbits precess about a warped intermediate surface called the Laplace 'plane.' Herein we derive general formulas for locating the Laplace plane. Because Uranus and Pluto have high obliquities, their Laplace planes are severely warped. We present maps of these Laplace planes, of interest in telescopic searches for new satellites. The Laplace plane of the Solar System as a whole is similarly distorted, but comets in the inner Oort cloud precess too slowly to sense the Laplace plane.

  17. Plane waves in noncommutative fluids

    NASA Astrophysics Data System (ADS)

    Abdalla, M. C. B.; Holender, L.; Santos, M. A.; Vancea, I. V.

    2013-08-01

    We study the dynamics of the noncommutative fluid in the Snyder space perturbatively at the first order in powers of the noncommutative parameter. The linearized noncommutative fluid dynamics is described by a system of coupled linear partial differential equations in which the variables are the fluid density and the fluid potentials. We show that these equations admit a set of solutions that are monochromatic plane waves for the fluid density and two of the potentials and a linear function for the third potential. The energy-momentum tensor of the plane waves is calculated.

  18. Space-Plane Spreadsheet Program

    NASA Technical Reports Server (NTRS)

    Mackall, Dale

    1993-01-01

    Basic Hypersonic Data and Equations (HYPERDATA) spreadsheet computer program provides data gained from three analyses of performance of space plane. Equations used to perform analyses derived from Newton's second law of physics, derivation included. First analysis is parametric study of some basic factors affecting ability of space plane to reach orbit. Second includes calculation of thickness of spherical fuel tank. Third produces ratio between volume of fuel and total mass for each of various aircraft. HYPERDATA intended for use on Macintosh(R) series computers running Microsoft Excel 3.0.

  19. Dilemmas in rationing health care services: the case for implicit rationing.

    PubMed Central

    Mechanic, D.

    1995-01-01

    With tension between the demand for health services and the cost of providing them, rationing is increasingly evident in all medical systems. Until recently, rationing was primarily through the ability to pay or achieved implicitly by doctors working within fixed budgets. Such forms of rationing are commonly alleged to be inequitable and inefficient and explicit rationing is advocated as more appropriate. Utilisation management in the United States and quasi-markets separating purchasing from provision in the United Kingdom are seen as ways of using resources more efficiently and are increasingly explicit. There is also advocacy to ration explicitly at the point of service. Mechanic reviews the implications of these developments and explains why explicit approaches are likely to focus conflict and dissatisfaction and be politically unstable. Explicit rationing is unlikely to be as equitable as its proponents argue and is likely to make dissatisfaction and perceived deprivation more salient. Despite its limitations, implicit rationing at the point of service is more sensitive to the complexity of medical decisions and the needs and personal and cultural preferences of patients. All systems use a mix of rationing devices, but the clinical allocation of services should substantially depend on the discretion of professionals informed by practice guidelines, outcomes research, and other informational aids. Images p1657-a p1659-a PMID:7795458

  20. Section curve reconstruction and mean-camber curve extraction of a point-sampled blade surface.

    PubMed

    Li, Wen-long; Xie, He; Li, Qi-dong; Zhou, Li-ping; Yin, Zhou-ping

    2014-01-01

    The blade is one of the most critical parts of an aviation engine, and a small change in the blade geometry may significantly affect the dynamics performance of the aviation engine. Rapid advancements in 3D scanning techniques have enabled the inspection of the blade shape using a dense and accurate point cloud. This paper proposes a new method to achieving two common tasks in blade inspection: section curve reconstruction and mean-camber curve extraction with the representation of a point cloud. The mathematical morphology is expanded and applied to restrain the effect of the measuring defects and generate an ordered sequence of 2D measured points in the section plane. Then, the energy and distance are minimized to iteratively smoothen the measured points, approximate the section curve and extract the mean-camber curve. In addition, a turbine blade is machined and scanned to observe the curvature variation, energy variation and approximation error, which demonstrates the availability of the proposed method. The proposed method is simple to implement and can be applied in aviation casting-blade finish inspection, large forging-blade allowance inspection and visual-guided robot grinding localization. PMID:25551467

  1. Section Curve Reconstruction and Mean-Camber Curve Extraction of a Point-Sampled Blade Surface

    PubMed Central

    Li, Wen-long; Xie, He; Li, Qi-dong; Zhou, Li-ping; Yin, Zhou-ping

    2014-01-01

    The blade is one of the most critical parts of an aviation engine, and a small change in the blade geometry may significantly affect the dynamics performance of the aviation engine. Rapid advancements in 3D scanning techniques have enabled the inspection of the blade shape using a dense and accurate point cloud. This paper proposes a new method to achieving two common tasks in blade inspection: section curve reconstruction and mean-camber curve extraction with the representation of a point cloud. The mathematical morphology is expanded and applied to restrain the effect of the measuring defects and generate an ordered sequence of 2D measured points in the section plane. Then, the energy and distance are minimized to iteratively smoothen the measured points, approximate the section curve and extract the mean-camber curve. In addition, a turbine blade is machined and scanned to observe the curvature variation, energy variation and approximation error, which demonstrates the availability of the proposed method. The proposed method is simple to implement and can be applied in aviation casting-blade finish inspection, large forging-blade allowance inspection and visual-guided robot grinding localization. PMID:25551467

  2. Structured eigenvalue problems for rational gauss quadrature

    NASA Astrophysics Data System (ADS)

    Fasino, Dario; Gemignani, Luca

    2007-08-01

    The connection between Gauss quadrature rules and the algebraic eigenvalue problem for a Jacobi matrix was first exploited in the now classical paper by Golub and Welsch (Math. Comput. 23(106), 221?230, 1969). From then on many computational problems arising in the construction of (polynomial) Gauss quadrature formulas have been reduced to solving direct and inverse eigenvalue problems for symmetric tridiagonals. Over the last few years (rational) generalizations of the classical Gauss quadrature formulas have been studied, i.e., formulas integrating exactly in spaces of rational functions. This paper wants to illustrate that stable and efficient procedures based on structured numerical linear algebra techniques can also be devised for the solution of the eigenvalue problems arising in the field of rational Gauss quadrature.

  3. Affine Contractions on the Plane

    ERIC Educational Resources Information Center

    Celik, D.; Ozdemir, Y.; Ureyen, M.

    2007-01-01

    Contractions play a considerable role in the theory of fractals. However, it is not easy to find contractions which are not similitudes. In this study, it is shown by counter examples that an affine transformation of the plane carrying a given triangle onto another triangle may not be a contraction even if it contracts edges, heights or medians.…

  4. Partition of perceived space within the fusional area on the basis of apparent fronto-parallel plane criterion.

    PubMed

    Drobe, B; Monot, A

    1997-07-01

    The relationship between visual space and physical space was investigated by means of the apparent fronto-parallel plane percept. A set of curves in physical space, corresponding to fronto-parallel planes perceived in front or behind a given fixation point, was determined. The curvature at the apex of these curves follows a hyperbolic law that depends on the distance between the perceived plane and the fixation point. Our results are interpreted by distinguishing absolute disparity, which sets the position of the perceived plane, from relative disparity measured by adjusting in this plane eccentric vertical lines. We show that Foley's model, which interprets the shape of the apparent fronto-parallel planes on the mis-evaluation of egocentric distance, works for absolute disparity judgements, but seems to be inadequate for relative disparity judgements in our experimental conditions. PMID:9390378

  5. An Atlas for Interpreting γ-Ray Pulsar Light Curves

    NASA Astrophysics Data System (ADS)

    Watters, Kyle P.; Romani, Roger W.; Weltevrede, Patrick; Johnston, Simon

    2009-04-01

    We have simulated a population of young spin-powered pulsars and computed the beaming pattern and light curves for the three main geometrical models: polar-cap emission, two-pole caustic ("slot gap") emission and outer-magnetosphere emission. The light curve shapes depend sensitively on the magnetic inclination α and viewing angle ζ. We present the results as maps of observables such as peak multiplicity and γ-ray peak separation in the (α, ζ) plane. These diagrams can be used to locate allowed regions for radio-loud and radio-quiet pulsars and to convert observed fluxes to true all-sky emission.

  6. Rationality: a social-epistemology perspective

    PubMed Central

    Vanpoucke, Danny E. P.; Douven, Igor

    2014-01-01

    Both in philosophy and in psychology, human rationality has traditionally been studied from an “individualistic” perspective. Recently, social epistemologists have drawn attention to the fact that epistemic interactions among agents also give rise to important questions concerning rationality. In previous work, we have used a formal model to assess the risk that a particular type of social-epistemic interactions lead agents with initially consistent belief states into inconsistent belief states. Here, we continue this work by investigating the dynamics to which these interactions may give rise in the population as a whole. PMID:24994987

  7. Bimetallic PtxCoy nanoparticles with curved faces for highly efficient hydrogenation of cinnamaldehyde

    NASA Astrophysics Data System (ADS)

    Gu, Yan; Zhao, Yonghui; Wu, Panpan; Yang, Bo; Yang, Nating; Zhu, Yan

    2016-05-01

    The control of the curved structure of bimetallic nanocrystals is a challenge, due to the rate differential for atom deposition and surface diffusion of alien atomic species on specific crystallographic planes of seeds. Herein, we report how to tune the degree of concavity of bimetallic PtxCoy concave nanoparticles using carboxylic acids as surfactants with an oleylamine system, leading to the specific crystallographic planes being exposed. The terminal carboxylic acids with a bridge ring or a benzene ring serving as structure regulators could direct the formation of curved faces with exposed high-index facets, and long-chain saturated fatty acids favored the production of curved faces with exposed low-index facets, while long-chain olefin acids alone benefited the formation of a flat surface with exposed low-index planes. Furthermore, these PtxCoy particles with curved faces displayed superior catalytic behaviour to cinnamaldehyde hydrogenation when compared with PtxCoy with flat faces. PtxCoy nanoparticles with curved faces exhibited over 6-fold increase in catalytic activity compared to PtxNiy nanoparticles with curved faces, and near 40-fold activity increase was observed in comparison with PtxFey nanoparticles with curved faces.The control of the curved structure of bimetallic nanocrystals is a challenge, due to the rate differential for atom deposition and surface diffusion of alien atomic species on specific crystallographic planes of seeds. Herein, we report how to tune the degree of concavity of bimetallic PtxCoy concave nanoparticles using carboxylic acids as surfactants with an oleylamine system, leading to the specific crystallographic planes being exposed. The terminal carboxylic acids with a bridge ring or a benzene ring serving as structure regulators could direct the formation of curved faces with exposed high-index facets, and long-chain saturated fatty acids favored the production of curved faces with exposed low-index facets, while long

  8. Optimization of starshades: focal plane versus pupil plane

    NASA Astrophysics Data System (ADS)

    Flamary, R.; Aime, C.

    2014-09-01

    We search for the best possible transmission for an external occulter coronagraph that is dedicated to the direct observation of terrestrial exoplanets. We show that better observation conditions are obtained when the flux in the focal plane is minimized in the zone in which the exoplanet is observed, instead of for the total flux received by the telescope. We describe the transmission of the occulter as a sum of basis functions. For each element of the basis, we numerically computed the Fresnel diffraction at the aperture of the telescope and the complex amplitude at its focus. The basis functions are circular disks that are linearly apodized over a few centimeters (truncated cones). We complemented the numerical calculation of the Fresnel diffraction for these functions by a comparison with pure circular disks (cylinder) for which an analytical expression, based on a decomposition in Lommel series, is available. The technique of deriving the optimal transmission for a given spectral bandwidth is a classical regularized quadratic minimization of intensities, but linear optimizations can be used as well. Minimizing the integrated intensity on the aperture of the telescope or for selected regions of the focal plane leads to slightly different transmissions for the occulter. For the focal plane optimization, the resulting residual intensity is concentrated behind the geometrical image of the occulter, in a blind region for the observation of an exoplanet, and the level of background residual starlight becomes very low outside this image. Finally, we provide a tolerance analysis for the alignment of the occulter to the telescope, which also favors the focal plane optimization. This means that telescope offsets of a few decimeters do not strongly reduce the efficiency of the occulter.

  9. Curved laser microjet in near field.

    PubMed

    Kotlyar, Victor V; Stafeev, Sergey S; Kovalev, Alexey A

    2013-06-20

    With the use of the finite-difference time-domain-based simulation and a scanning near-field optical microscope that has a metal cantilever tip, the diffraction of a linearly polarized plane wave of wavelength λ by a glass corner step of height 2λ is shown to generate a low divergence laser jet of a root-parabolic form: over a distance of 4.7λ on the optical axis, the beam path is shifted by 2.1λ. The curved laser jet of the FWHM length depth of focus=9.5λ has the diameter FWHM=1.94λ over the distance 5.5λ, and the intensity maximum is 5 times higher than the incident wave intensity. The discrepancy between the analytical and the experimental results amounts to 11%. PMID:23842153

  10. Out-of-Plane Deflections as a Diagnostic Tool and Application to PEP-II

    SciTech Connect

    Venturini, Marco

    2001-02-01

    We derive simplified formulae that relate the ''out-of-plane'' beam-beam deflections of colliding e{sup +} and e{sup -} beams, to the off-diagonal entry of the {Sigma}-matrix expressing the convoluted beam sizes. These formulae can be used to fit measured deflection curves and extract information about the relative tilt angle of two colliding bunches in the transverse plane.

  11. Adaptive signed distance transform for curves with guaranteed error bounds

    SciTech Connect

    Laney, D A; Duchaineau, M A; Max, N L

    2000-12-04

    We present an adaptive signed distance transform algorithm for curves in the plane. The algorithm provides guaranteed error bounds with a selective refinement approach. The domain over which the signed distance function is desired is adaptive triangulated and piecewise discontinuous linear approximations are constructed within each triangle. The resulting transform performs work only were requested and does not rely on a preset sampling rate or other constraints.

  12. Rational Rhymes for Addressing Common Childhood Issues

    ERIC Educational Resources Information Center

    Warren, Jeffrey M.

    2011-01-01

    Music-based interventions are valuable tools counselors can use when working with children. Specific types of music-based interventions, such as songs or rhymes, can be especially pertinent in addressing the thoughts, feelings, and behaviors of children. Rational-emotive behavior therapy (REBT) provides a therapeutic framework that encourages…

  13. Solving Rational Expectations Models Using Excel

    ERIC Educational Resources Information Center

    Strulik, Holger

    2004-01-01

    Simple problems of discrete-time optimal control can be solved using a standard spreadsheet software. The employed-solution method of backward iteration is intuitively understandable, does not require any programming skills, and is easy to implement so that it is suitable for classroom exercises with rational-expectations models. The author…

  14. RATIONALIZATION OF THE RURAL-URBAN MIGRATION.

    ERIC Educational Resources Information Center

    MIRENGOFF, WILLIAM

    ALTHOUGH THE PATTERN OF RURAL TO URBAN MIGRATION IS BEGINNING TO SUBSIDE, THE PROBLEMS OF EMPLOYMENT FACED BY THESE RURAL MIGRANTS ARE CONTINUING. PROGRAMS TO DEAL EFFECTIVELY WITH THEIR RELOCATION AND EMPLOYMENT HAVE NOT BEEN DEVISED, AND EFFORTS TO DATE HAVE BEEN CURATIVE RATHER THAN PREVENTIVE. A PRACTICAL WAY TO RATIONALIZE THE RURAL-URBAN…

  15. Opinion Expression as a Rational Behavior.

    ERIC Educational Resources Information Center

    Kim, Sei-Hill

    This study looks at individuals' opinion expressions as a rational behavior based on a conscious calculus of expected benefits and costs (economic analysis). The influences of "issue benefit,""opinion congruence," and "issue knowledge," as sources of benefits and costs on opinion expression were hypothesized and tested. The study also examined the…

  16. Imitation in Infancy: Rational or Motor Resonance?

    ERIC Educational Resources Information Center

    Paulus, Markus; Hunnius, Sabine; Vissers, Marlies; Bekkering, Harold

    2011-01-01

    The present study investigates the contribution of 2 mechanisms to imitation in infancy. The principle of rational action suggests that infants normatively evaluate the efficiency of observed actions. In contrast, it has been proposed that motor resonance (i.e., the mapping of others' actions onto one's own motor repertoire) plays a central role…

  17. Expressive Thought and Non-Rational Inquiry.

    ERIC Educational Resources Information Center

    Newton, Richard F.

    A significant problem with inquiry teaching is that too much emphasis is placed on inquiry as a logical, scientific, and rational way of knowing. Feelings and mood are rarely dealt with except in rather off-handed remarks about intuitive leaps and creative encounters. Few consider what a model of inquiry based on mood and feeling might look like.…

  18. Rational Landen transformations on mathbb{R}

    NASA Astrophysics Data System (ADS)

    Manna, Dante; Moll, Victor H.

    2007-12-01

    The Landen transformation (a,b) mapsto ( (a+b)/2,sqrt{ab} ) preserves the value of an elliptic integral, and its iteration produces the classical arithmetic-geometric mean AGM (a,b) . We present analogous transformations for rational functions integrated over the whole real line.

  19. The Assessment of Rational Thinking: IQ ? RQ

    ERIC Educational Resources Information Center

    Stanovich, Keith E.; West, Richard F.

    2014-01-01

    In this article the authors argue that distinguishing between rationality and intelligence helps explain how people can be, at the same time, intelligent and irrational (Stanovich, 2009). As such, researchers need to study separately the individual differences in cognitive skills that underlie intelligence and the individual differences in…

  20. Reflections on Rational-Emotive Therapy.

    ERIC Educational Resources Information Center

    Ellis, Albert

    1993-01-01

    Reflects rational-emotive therapy (RET) in 1955 and discusses some of its recent constructivist and humanist theories and practice. Distinguishes between general RET, called synonymous with general cognitive-behavioral therapy, from preferential RET, called unique kind of cognitive therapy that partially overlaps with general cognitive-behavioral…

  1. Rational Emotive Behavior Therapy with Troubled Students.

    ERIC Educational Resources Information Center

    Zionts, Paul; Zionts, Laura

    1997-01-01

    Based on the early work of Albert Ellis, seeks to identify and challenge irrational beliefs that underlie behavior problems. Outlines concepts and methods of Rational Emotive Behavior Theory and describes the application both in counseling and as a mental health curriculum for troubled children and youth. Offers classroom techniques. (RJM)

  2. Macroeconomics after Two Decades of Rational Expectations.

    ERIC Educational Resources Information Center

    McCallum, Bennett T.

    1994-01-01

    Discusses real business cycle analysis, growth theory, and other economic concepts in the context of the rational expectations revolution in macroeconomics. Focuses on post-1982 research. Concludes that the rejuvenation of growth analysis is an encouraging development because it could lead to changes in welfare policy. (CFR)

  3. Rational Suggestions for Pre-Marital Counseling.

    ERIC Educational Resources Information Center

    Ball, J.D.; Henning, Lawrence H.

    1981-01-01

    To demonstrate the utility of Rational Emotive Therapy in pre-marital counseling, examples of specific irrational beliefs which clinicians can use to help couples are presented. Mental health practitioners are encouraged to apply these principles to other specific irrationalities they may discover in their own work experience. (Author)

  4. Some Contemporary Rational Emotive Behavior Therapy Songs.

    ERIC Educational Resources Information Center

    Watts, Richard E.

    1996-01-01

    Presents several new rational emotive behavior therapy (REBT) songs. Claims that the songs may be used in both academic and therapeutic settings as a humorous way to address cognitive distortions or irrational beliefs. Reports that students and clients have responded favorably to these songs. (RJM)

  5. Rational and Mechanistic Perspectives on Reinforcement Learning

    ERIC Educational Resources Information Center

    Chater, Nick

    2009-01-01

    This special issue describes important recent developments in applying reinforcement learning models to capture neural and cognitive function. But reinforcement learning, as a theoretical framework, can apply at two very different levels of description: "mechanistic" and "rational." Reinforcement learning is often viewed in mechanistic terms--as…

  6. Synthetic RR Lyrae velocity curves

    SciTech Connect

    Liu, Tianxing Boston Univ., MA )

    1991-02-01

    An amplitude correlation between the pulsation velocity curves and visual light curves of ab-type RR Lyrae stars is derived from a large number of RR Lyrae that have high-precision radial-velocity and photometric data. Based on the determined AVp, AV ralation, a synthetic radial-velocity curve for a typical ab-type RR Lyrae star is constructed. This would be of particular use in determining the systemic velocities of RR Lyrae. 17 refs.

  7. Eight plane IPND mechanical testing.

    SciTech Connect

    Zhao, A.; Guarino, V.; Wood, K.; Nephew, T.; Ayres, D.; Lee, A.; High Energy Physics; FNAL

    2008-03-18

    A mechanical test of an 8 plane IPND mechanical prototype, which was constructed using extrusions from the testing/tryout of the 16 cell prototype extrusion die in Argonne National Laboratory, was conducted. There were 4 vertical and 4 horizontal planes in this 8 plane IPND prototype. Each vertical plane had four 16 cell extrusions, while each horizontal plane had six 16 cell extrusions. Each plane was glued together using the formulation of Devcon adhesive, Devcon 60. The vertical extrusions used in the vertical planes shares the same dimensions as the horizontal extrusions in the horizontal planes with the average web thickness of 2.1 mm and the average wall thickness of 3.1 mm. This mechanical prototype was constructed with end-seals on the both ends of the vertical extrusions. The gaps were filled with epoxy between extrusions and end-seals. The overall dimension of IPND is 154.8 by 103.1 by 21.7 inches with the weight of approximately 1200 kg, as shown in a figure. Two similar mechanical tests of 3 layer and 11 layer prototypes have been done in order to evaluate the strength of the adhesive joint between extrusions in the NOvA detector. The test showed that the IPND prototype was able to sustain under the loading of weight of itself and scintillator. Two FEA models were built to verify the measurement data from the test. The prediction from FEA slice model seems correlated reasonably well to the test result, even under a 'rough' estimated condition for the wall thickness (from an untuned die) and an unknown property of 'garage type' extrusion. A full size of FEA 3-D model also agrees very well with the test data from strain gage readings. It is worthy to point out that the stress distribution of the structure is predominantly determined by the internal pressure, while the buckling stability relies more on the loading weight from the extrusions themselves and scintillate. Results of conducted internal pressure tests, including 3- cell, 11-cell and the IPND

  8. Plane Wave and Coulomb Asymptotics

    NASA Astrophysics Data System (ADS)

    Mulligan, P. G.; Crothers, D. S. F.

    2004-01-01

    A simple plane wave solution of the Schrödinger Helmholtz equation is a quantum eigenfunction obeying both energy and linear momentum correspondence principles. Inclusion of the outgoing wave with scattering amplitude f obeys unitarity and the optical theorem. By closely considering the standard asymptotic development of the plane wave, we show that there is a problem with angular momentum when we consider forward scattering at the point of closest approach and at large impact parameter given semiclassically by (l + 1/2)/k where l is the azimuthal quantum number and may be large (J Leech et al, Phys. Rev. Lett. 88 257901 (2002)). The problem is resolved via non-uniform, non-standard analysis involving the Heaviside step function, unifying classical, semiclassical and quantum mechanics, and the treatment is extended to the case of pure Coulomb scattering.

  9. Growth and energy budget of juvenile lenok Brachymystax lenok in relation to ration level

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Li, Zhongjie; Zhang, Tanglin; Yuan, Jing; Mou, Zhenbo; Liu, Jiashou

    2015-03-01

    We evaluated the effect of ration level (RL) on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok (initial mean body weight 3.06±0.13 g) were fed for 21 d at five different ration levels: starvation, 2%, 3%, 4% bwd (body weight per day, based on initial mean values), and apparent satiation. Feed consumption, apparent digestibility, and growth were directly measured. Specific growth rates in terms of wet weight, dry weight, protein, and energy increased logarithmically with an increase in ration levels. The relationship between specific growth rate in terms of wet weight (SGRw, %/d) and RL (%) was characterized by a decelerating curve: SGRw=-1.417+3.166ln(RL+1). The apparent digestibility coefficients of energy exhibited a decreasing pattern with increasing ration level, and there was a significant difference among different RLs. Body composition was significantly affected by ration size. The relationship between feed efficiency rate in terms of energy (FERe) and RL was: FERe=-14.167+23.793RL-3.367(RL)2, and the maximum FERe was observed at a 3.53% ration. The maintenance requirement for energy of juvenile lenok was 105.39 kJ BW (kg)-0.80/d, the utilization efficiency of DE for growth was 0.496. The energy budget equation at satiation was: 100IE=29.03FE+5.78(ZE+UE)+39.56 HE+25.63 RE, where IE is feed energy, FE is fecal energy, ZE+UE is excretory energy, HE is heat production, and RE is recovered energy. Our results suggest that the most suitable feeding rate for juvenile lenok aquaculture for wet weight growth is 2.89% bwd, whereas for energy growth, the suggested rate is 3.53% bwd at this growth stage.

  10. Orbital Space Plane (OSP) Program

    NASA Technical Reports Server (NTRS)

    McKenzie, Patrick M.

    2003-01-01

    Lockheed Martin has been an active participant in NASA's Space Launch Initiative (SLI) programs over the past several years. SLI, part of NASA's Integrated Space Transportation Plan (ISTP), was restructured in November of 2002 to focus the overall theme of safer, more afford-able space transportation along two paths - the Orbital Space Plane Program and the Next Generation Launch Technology programs. The Orbital Space Plane Program has the goal of providing rescue capability from the International Space Station by 2008 and transfer capability for crew (and limited cargo) by 2012. The Next Generation Launch Technology program is combining research and development efforts from the 2nd Generation Reusable Launch Vehicle (2GRLV) program with cutting-edge, advanced space transportation programs (previously designated 3rd Generation) into one program aimed at enabling safe, reliable, cost-effective reusable launch systems by the middle of the next decade. Lockheed Martin is one of three prime contractors working to bring Orbital Space Plane system concepts to a system definition level of maturity by December of 2003. This paper and presentation will update the international community on the progress of the' OSP program, from an industry perspective, and provide insights into Lockheed Martin's role in enabling the vision of a safer, more affordable means of taking people to and from space.

  11. Symmetry in finite phase plane

    NASA Astrophysics Data System (ADS)

    Zak, J.

    2010-03-01

    The known symmetries in one-dimensional systems are inversion and translations. These symmetries persist in finite phase plane, but a novel symmetry arises in view of the discrete nature of the coordinate xi and the momentum pi : xi and pi can undergo permutations. Thus, if xi assumes M discrete values, i = 0, 1,2,..., M - 1, a permutation will change the order of the set x0,x1,..., xM-1 into a new ordered set. Such a symmetry element does not exist for a continuous x-coordinate in an infinite phase plane. Thus, in a finite phase plane, translations can be replaced by permutations. This is also true for the inversion operator. The new permutation symmetry has been used for the construction of conjugate representations and for the splitting of the M-dimensional vector space into independent subspaces. This splitting is exhaustive in the sense that if M = iMi with Mi being prime numbers, the M-dimensional space splits into M1,M2,...Mn-dimensional independent subspaces. It is shown that following this splitting one can design new potentials with appropriate constants of motion. A related problem is the Weyl-Heisenberg group in the M-dimensional space which turns into a direct product of its subgroups in the Mi-dimensional subspaces. As an example we consider the case of M = 8.

  12. In-plane magnetization behaviors in the Shastry-Sutherland system TbB{sub 4}: Monte Carlo simulation

    SciTech Connect

    Feng, J. J.; Li, W. C.; Qin, M. H. E-mail: liujm@nju.edu.cn; Xie, Y. L.; Yan, Z. B.; Liu, J.-M. E-mail: liujm@nju.edu.cn; Jia, X. T.

    2015-05-07

    The in-plane magnetization behaviors in TbB{sub 4} are theoretically studied using the frustrated classical XY model, including the exchange and biquadratic interactions, and the anisotropy energy. The magnetization curves at various temperatures are simulated, and the magnetic orders are uncovered by the tracking of the spin configurations. In addition, the effects of the in-plane anisotropy and biquadratic interaction on the magnetization curves are investigated in detail. The simulated results suggest that the magnetic anisotropy within the (001) plane owes to the complex interplay between these couplings, and the anisotropy term plays an important role.

  13. Theory of rigid-plane phonon modes in layered crystals

    NASA Astrophysics Data System (ADS)

    Michel, K. H.; Verberck, B.

    2012-03-01

    The lattice dynamics of low-frequency rigid-plane modes in metallic (graphene multilayers, GML) and in insulating (hexagonal boron-nitride multilayers, BNML) layered crystals is investigated. The frequencies of shearing and compression (stretching) modes depend on the layer number N and are presented in the form of fan diagrams. The results for GML and BNML are very similar. In both cases, only the interactions (van der Waals and Coulomb) between nearest-neighbor planes are effective, while the interactions between more distant planes are screened. A comparison with recent Raman scattering results on low-frequency shear modes in GML [Tan , Nat. Mater., in press, doi:10.1038/nmat3245, (2012)] is made. Relations with the low-lying rigid-plane phonon dispersions in the bulk materials are established. Master curves, which connect the fan diagram frequencies for any given N, are derived. Static and dynamic thermal correlation functions for rigid-layer shear and compression modes are calculated. The results might be of use for the interpretation of friction force experiments on multilayer crystals.

  14. Rational Choice and Developmental Influences on Recidivism Among Adolescent Felony Offenders

    PubMed Central

    Fagan, Jeffrey; Piquero, Alex R.

    2009-01-01

    Recent case law and social science both have claimed that the developmental limitations of adolescents affect their capacity for control and decision making with respect to crime, diminishing their culpability and reducing their exposure to punishment. Social science has focused on two concurrent adolescent developmental influences: the internalization of legal rules and norms that regulate social and antisocial behaviors, and the development of rationality to frame behavioral choices and decisions. The interaction of these two developmental processes, and the identification of one domain of socialization and development as the primary source of motivation or restraint in adolescence, is the focus of this article. Accordingly, we combine rational choice and legal socialization frameworks into an integrated, developmental model of criminality. We test this framework in a large sample of adolescent felony offenders who have been interviewed at six-month intervals for two years. Using hierarchical and growth curve models, we show that both legal socialization and rational choice factors influence patterns of criminal offending over time. When punishment risks and costs are salient, crime rates are lower over time. We show that procedural justice is a significant antecedent of legal socialization, but not of rational choice. We also show that both mental health and developmental maturity moderate the effects of perceived crime risks and costs on criminal offending. PMID:20148123

  15. Rational Choice and Developmental Influences on Recidivism Among Adolescent Felony Offenders.

    PubMed

    Fagan, Jeffrey; Piquero, Alex R

    2007-12-01

    Recent case law and social science both have claimed that the developmental limitations of adolescents affect their capacity for control and decision making with respect to crime, diminishing their culpability and reducing their exposure to punishment. Social science has focused on two concurrent adolescent developmental influences: the internalization of legal rules and norms that regulate social and antisocial behaviors, and the development of rationality to frame behavioral choices and decisions. The interaction of these two developmental processes, and the identification of one domain of socialization and development as the primary source of motivation or restraint in adolescence, is the focus of this article. Accordingly, we combine rational choice and legal socialization frameworks into an integrated, developmental model of criminality. We test this framework in a large sample of adolescent felony offenders who have been interviewed at six-month intervals for two years. Using hierarchical and growth curve models, we show that both legal socialization and rational choice factors influence patterns of criminal offending over time. When punishment risks and costs are salient, crime rates are lower over time. We show that procedural justice is a significant antecedent of legal socialization, but not of rational choice. We also show that both mental health and developmental maturity moderate the effects of perceived crime risks and costs on criminal offending. PMID:20148123

  16. Surface path lines in plane stokes flow driven by capillarity

    SciTech Connect

    Hopper, R.W.

    1993-05-03

    Consider the free creeping viscous plane flow in a region, bounded by a simple smooth closed curve and driven solely by surface tension. The shape evolution may in principle, and often in practice, be described by a time-dependent mapping z = {Omega}({zeta},t) of the unit circle, conformal on {vert_bar}{zeta}{vert_bar} {le} 1. It is shown that the path lines of fluid elements at the surface are determined by a first-order ordinary differential equation involving {Omega}({zeta},t), together with an initial condition. Typically, this must be integrated numerically. Velocities are not needed. The analogous theory for maps from the half-plane Im {zeta} {ge} 0 is presented. Surface path lines of a collapsing elliptic hole, in two reference frames, are calculated.

  17. Motion of an inclined cylinder on an inclined plane

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2015-09-01

    We consider in this paper the motion of an inclined cylinder on an inclined plane. At low inclined plane angles, the cylinder rolls without slipping across the incline, in a direction perpendicular to its long axis. At steeper angles, long cylinders follow a straight line path in a direction that veers away from the low angle path. Short cylinders follow a curved path. These effects are described in terms of a transition from rolling to sliding as the incline angle is increased. The results help to explain why a vehicle normally turns in the direction that the wheels are pointing and why a vehicle can veer away from that direction on a slippery surface.

  18. Tool For Making Curved Holes

    NASA Technical Reports Server (NTRS)

    Allard, Robert; Calve, Andrew; Pastreck, Edwin; Padden, Edward

    1992-01-01

    Tool for use in electrical-discharge machining (EDM) guides EDM electrode in making curved holes. Guide rod fits in slot in arm, which moves through arc. Motion drives electrode into workpiece along desired curved path. Electrode burns into workpiece while arm rotates on spindle. Discharge cuts hole of same radius of curvature.

  19. Digital-voltage curve generator

    NASA Technical Reports Server (NTRS)

    Perlman, M.

    1970-01-01

    Curve generator capable of producing precisely repeatable curve for any single-valued function of voltage versus time uses digital approach, implemented by means of clocked feedback shift register, large scale integrated circuit diode matrix comprising about 12,000 diodes, counter, and digital-to-analog converter.

  20. Quantum field theories on algebraic curves. I. Additive bosons

    NASA Astrophysics Data System (ADS)

    Takhtajan, Leon A.

    2013-04-01

    Using Serre's adelic interpretation of cohomology, we develop a `differential and integral calculus' on an algebraic curve X over an algebraically closed field k of constants of characteristic zero, define algebraic analogues of additive multi-valued functions on X and prove the corresponding generalized residue theorem. Using the representation theory of the global Heisenberg algebra and lattice Lie algebra, we formulate quantum field theories of additive and charged bosons on an algebraic curve X. These theories are naturally connected with the algebraic de Rham theorem. We prove that an extension of global symmetries (Witten's additive Ward identities) from the k-vector space of rational functions on X to the vector space of additive multi-valued functions uniquely determines these quantum theories of additive and charged bosons.

  1. The dyadic diffraction coefficient for a curved edge

    NASA Technical Reports Server (NTRS)

    Kouyoumjian, R. G.; Pathak, P. H.

    1974-01-01

    A compact dyadic diffraction coefficient for electromagnetic waves obliquely incident on a curved edge formed by perfectly conducting curved or plane surfaces is obtained. This diffraction coefficent remains valid in the transition regions adjacent to shadow and reflection boundaries, where the diffraction coefficients of Keller's original theory fail. The method is on Keller's method of the canonical problem, which in this case is the perfectly conducting wedge illuminated by plane, cylindrical, conical, and spherical waves. When the proper ray fixed coordinate system is introduced, the dyadic diffraction coefficient for the wedge is found to be the sum of only two dyads, and it is shown that this is also true for the dyadic diffraction coefficients of higher order edges. One dyad contains the acoustic soft diffraction coefficient; the other dyad contains the acoustic hard diffraction coefficient. The expressions for the acoustic wedge diffraction coefficients contain Fresnel integrals, which ensure that the total field is continuous at shadow and reflection boundaries. The diffraction coefficients have the same form for the different types of edge illumination; only the arguments of the Fresnel integrals are different. Since diffraction is a local phenomenon, and locally the curved edge structure is wedge shaped, this result is readily extended to the curved edge.

  2. Computation of Bound Orbits in the Plane of a Galaxy with a Flat Rotation Curve

    ERIC Educational Resources Information Center

    Bacon, M. E.; Sharrar, Amber

    2010-01-01

    A standard topic in an advanced undergraduate classical mechanics course is the determination of the orbits in a gravitational field. In the present paper we report on the calculation of bound orbits in the gravitational field of a spiral galaxy. Calculations such as these could serve to focus attention on an area of cutting edge astrophysics and…

  3. Focal properties of a plane grating in a convergent beam.

    PubMed

    Hall, J T

    1966-06-01

    Focusing from a plane grating can be accomplished by using convergent radiation incident on the grating in such a manner that any incident angle alpha(n), the resulting diffraction angle beta(n), will be on the same side of the grating normal. The theory for the focal properties is developed by applying Fermat's principle of least time to selected terms resulting from a finite series expansion of the system's distance function. Derivations are given for finding the focal curve equation, astigmatism, and coma, of the most usable configuration of the optical components. Discussions of the aberrations disclose methods for eliminating the astigmatism and reducing the coma. PMID:20049009

  4. Development of the Rational Behavior Inventory: Initial Validity and Reliability

    ERIC Educational Resources Information Center

    Shorkey, Clayton T.; Whiteman, Victor L.

    1977-01-01

    The results of initial validity and reliability studies on the Rational Behavior Inventory are presented. The instrument was developed to be used for assessment, treatment planning, and evaluation of clients by counselors who use Rational Emotive Therapy. (Author/JKS)

  5. Cognitive Distance, Absorptive Capacity and Group Rationality: A Simulation Study

    PubMed Central

    Curşeu, Petru Lucian; Krehel, Oleh; Evers, Joep H. M.; Muntean, Adrian

    2014-01-01

    We report the results of a simulation study in which we explore the joint effect of group absorptive capacity (as the average individual rationality of the group members) and cognitive distance (as the distance between the most rational group member and the rest of the group) on the emergence of collective rationality in groups. We start from empirical results reported in the literature on group rationality as collective group level competence and use data on real-life groups of four and five to validate a mathematical model. We then use this mathematical model to predict group level scores from a variety of possible group configurations (varying both in cognitive distance and average individual rationality). Our results show that both group competence and cognitive distance are necessary conditions for emergent group rationality. Group configurations, in which the groups become more rational than the most rational group member, are groups scoring low on cognitive distance and scoring high on absorptive capacity. PMID:25314132

  6. National Aero-Space Plane

    NASA Technical Reports Server (NTRS)

    Piland, William M.

    1987-01-01

    An account is given of the technology development management objectives thus far planned for the DOD/NASA National Aero-Space Plane (NASP). The technology required by NASP will first be developed in ground-based facilities and then integrated during the design and construction of the X-30 experimental aircraft. Five airframe and three powerplant manufacturers are currently engaged in an 18-month effort encompassing design studies and tradeoff analyses. The first flight of the X-30 is scheduled for early 1993.

  7. SNAP Satellite Focal Plane Development

    SciTech Connect

    Bebek, C.; Akerlof, C.; Aldering, G.; Amanullah, R.; Astier, P.; Baltay, C.; Barrelet, E.; Basa, S.; Bercovitz, J.; Bergstrom, L.; Berstein, G.P.; Bester, M.; Bohlin, R.; Bonissent, A.; Bower, C.; Campbell, M.; Carithers, W.; Commins, E.; Day, C.; Deustua, S.; DiGennaro, R.; Ealet, A.; Ellis, R.; Emmett, W.; Eriksson, M.; Fouchez,D.; Fruchter, A.; Genat, J-F.; Goldhaber, G.; Goobar, A.; Groom, D.; Heetderks, H.; Holland, S.; Huterer, D.; Johnson, W.; Kadel, R.; Karcher,A.; Kim, A.; Kolbe, W.; Lafever, R.; Lamoureaux, J.; Lampton, M.; Lefevre, O.; Levi, M.; Levin, D.; Linder, E.; Loken, S.; Malina, R.; Mazure, A.; McKay, T.; McKee, S.; Miquel, R.; Morgan, N.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Roe, N.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Prieto, E.; Rabinowitz,D.; Refregier, A.; Rhodes, J.; Schubnell, M.; Sholl, M.; Smadja, G.; Smith, R.; Smoot, G.; Snyder, J.; Spadafora, A.; Szymkowiak, A.; Tarle,G.; Taylor, K.; Tilquin, A.; Tomasch, A.; Vincent, D.; von der Lippe, H.; Walder, J-P.; Wang, G.

    2003-07-07

    The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square degree field in the visible and near-infrared wavelength regime. The requirements for the instrument suite and the present configuration of the focal plane concept are presented. A two year R&D phase, largely supported by the Department of Energy, is just beginning. We describe the development activities that are taking place to advance our preparedness for mission proposal in the areas of detectors and electronics.

  8. Rationally Irrational: The Case of Sexual Burglary.

    PubMed

    Pedneault, Amelie; Beauregard, Eric; Harris, Danielle A; Knight, Raymond A

    2015-08-01

    The present study investigated rationality in sexually motivated burglaries. Specifically, we analyzed the situational cues identified by sexual burglars in their target selection. The research project investigated 224 individual incidents of residential burglary with apparent sexual motivations. Situational characteristics of the incidents were recorded and analyzed using forward sequential regressions. Results indicated that most sexually motivated burglaries occurred in occupied residences with deficient physical guardianship, when the victim was alone. Violence, theft, penetration, and fetishism were found to be committed in circumstances that increased the benefits and lowered the risks. Results showed that sexual burglary is rational in nature-sexual burglars chose residences that were easy to break into. We found little support for the premise that such opportunities arose while carrying out regular burglaries. Instead, the data indicated that sexual burglars acted opportunistically on situational cues that are markedly dissimilar to those of regular burglars. PMID:24469848

  9. Rational orbits around charged black holes

    SciTech Connect

    Misra, Vedant; Levin, Janna

    2010-10-15

    We show that all eccentric timelike orbits in Reissner-Nordstroem spacetime can be classified using a taxonomy that draws upon an isomorphism between periodic orbits and the set of rational numbers. By virtue of the fact that the rationals are dense, the taxonomy can be used to approximate aperiodic orbits with periodic orbits. This may help reduce computational overhead for calculations in gravitational wave astronomy. Our dynamical systems approach enables us to study orbits for both charged and uncharged particles in spite of the fact that charged particle orbits around a charged black hole do not admit a simple one-dimensional effective potential description. Finally, we show that comparing periodic orbits in the Reissner-Nordstroem and Schwarzschild geometries enables us to distinguish charged and uncharged spacetimes by looking only at the orbital dynamics.

  10. Moral Credentialing and the Rationalization of Misconduct

    PubMed Central

    Brown, Ryan P.; Tamborski, Michael; Wang, Xiaoqian; Barnes, Collin D.; Mumford, Michael D.; Connelly, Shane; Devenport, Lynn D.

    2010-01-01

    Recent studies lead to the paradoxical conclusion that the act of affirming one’s egalitarian or pro-social values and virtues might subsequently facilitate prejudiced or self-serving behavior, an effect previously referred to as “moral credentialing.” The present study extends this paradox to the domain of academic misconduct and investigates the hypothesis that such an effect might be limited by the extent to which misbehavior is rationalizable. Using a paradigm designed to investigate deliberative and rationalized forms of cheating (von Hippel, Lakin, & Shakarchi, 2005), we found that when participants had credentialed themselves (versus a non-close acquaintance) via a set of hypothetical moral dilemmas, they were more likely to cheat on a subsequent math task, but only if cheating was highly rationalizable. When cheating was difficult to rationalize, moral credentialing had almost no impact on cheating. PMID:21503267