WorldWideScience

Sample records for uniformly accelerated frame

  1. Spacetime transformations from a uniformly accelerated frame

    International Nuclear Information System (INIS)

    Friedman, Yaakov; Scarr, Tzvi

    2013-01-01

    We use the generalized Fermi–Walker transport to construct a one-parameter family of inertial frames which are instantaneously comoving to a uniformly accelerated observer. We explain the connection between our approach and that of Mashhoon. We show that our solutions of uniformly accelerated motion have constant acceleration in the comoving frame. Assuming the weak hypothesis of locality, we obtain local spacetime transformations from a uniformly accelerated frame K′ to an inertial frame K. The spacetime transformations between two uniformly accelerated frames with the same acceleration are Lorentz. We compute the metric at an arbitrary point of a uniformly accelerated frame. (paper)

  2. Classical relativistic ideal gas in thermodynamic equilibrium in a uniformly accelerated reference frame

    International Nuclear Information System (INIS)

    Louis-Martinez, Domingo J

    2011-01-01

    A classical (non-quantum-mechanical) relativistic ideal gas in thermodynamic equilibrium in a uniformly accelerated frame of reference is studied using Gibbs's microcanonical and grand canonical formulations of statistical mechanics. Using these methods explicit expressions for the particle, energy and entropy density distributions are obtained, which are found to be in agreement with the well-known results of the relativistic formulation of Boltzmann's kinetic theory. Explicit expressions for the total entropy, total energy and rest mass of the gas are obtained. The position of the center of mass of the gas in equilibrium is found. The non-relativistic and ultrarelativistic approximations are also considered. The phase space volume of the system is calculated explicitly in the ultrarelativistic approximation.

  3. Transformations between inertial and linearly accelerated frames of reference

    International Nuclear Information System (INIS)

    Ashworth, D.G.

    1983-01-01

    Transformation equations between inertial and linearly accelerated frames of reference are derived and these transformation equations are shown to be compatible, where applicable, with those of special relativity. The physical nature of an accelerated frame of reference is unambiguously defined by means of an equation which relates the velocity of all points within the accelerated frame of reference to measurements made in an inertial frame of reference. (author)

  4. Dragging of inertial frames.

    Science.gov (United States)

    Ciufolini, Ignazio

    2007-09-06

    The origin of inertia has intrigued scientists and philosophers for centuries. Inertial frames of reference permeate our daily life. The inertial and centrifugal forces, such as the pull and push that we feel when our vehicle accelerates, brakes and turns, arise because of changes in velocity relative to uniformly moving inertial frames. A classical interpretation ascribed these forces to acceleration relative to some absolute frame independent of the cosmological matter, whereas an opposite view related them to acceleration relative to all the masses and 'fixed stars' in the Universe. An echo and partial realization of the latter idea can be found in Einstein's general theory of relativity, which predicts that a spinning mass will 'drag' inertial frames along with it. Here I review the recent measurements of frame dragging using satellites orbiting Earth.

  5. The zero-point field in non-inertial frames

    International Nuclear Information System (INIS)

    Hacyan, S.

    1985-01-01

    The energy spectrum of the zero-point field as seen in non-inertial frames is investigated. Uniformly accelerated frames and black holes are considered. It is suggested that the radiation produced by black holes or acceleration is a manifestation of the zero-point field and of the same nature (whether real or virtual)

  6. An accelerating reference frame for electromagnetic waves in a rapidly growing plasma

    International Nuclear Information System (INIS)

    Yablonovitch, E.

    1989-01-01

    In 1974, Hawking showed that black holes can evaporate by the emission of low temperature thermal radiation, now named Hawking radiation. Shortly thereafter, a closely related effect called Unruh radiation became apparent. The author discusses how, according to Unruh and Davies, observers of the electromagnetic field in an accelerating reference frame should see thermal radiation at a temperature T: KT = h/2π a/c where a is the acceleration relative to an inertial frame, c is the speed of light and h and K are Planck's and Boltzmann's constant respectively. In a frame accelerating at g = 980 cm/sec 2 , equivalent to the acceleration experienced at the earth's surface, this thermal radiation is at a temperature of only 4 x 10 -20 degrees K. Therefore, physicists hoping to observe this radiation, have sought out systems being subjected to extreme acceleration

  7. Uniform laser ablative acceleration of targets at 1014 W/cm2

    International Nuclear Information System (INIS)

    Obenschain, S.P.; Whitlock, R.R.; McLean, E.A.; Ripin, B.H.; Price, R.H.; Phillion, D.W.; Campbell, E.M.; Rosen, M.D.

    1982-01-01

    We present the first detailed investigations of the ablative acceleration of planar targets while simultaneously using high irradiance (10 14 W/cm 2 ), large focal diameters (1 mm) and long laser pulse duration (3 nsec). Included are measurements of target preheat, ablation pressures and uniformity achieved under these conditions. Targets were accelerated to high velocities with velocity profile uniformity approaching that required for high gain pellet implosions

  8. Effect of uniform acceleration on multiplayer quantum game

    International Nuclear Information System (INIS)

    Goudarzi, H; Beyrami, S

    2012-01-01

    We investigate the influence of the Unruh effect on three-qubit quantum games. In particular, we interpret the quantum Prisoners’ Dilemma, which is a famous, non-zero sum game both for entangled and unentangled initial states and show that the acceleration of non-inertial frames disturbs the symmetry of the game. Using the various strategies, the novel Nash equilibrium is obtained at infinite acceleration (r = π/4). As a remarkable point, it is shown that in our three-player system, in contrast to the two-player quantum game in non-inertial frames (see Khan et al 2011 J. Phys. A: Math. Theor. 44 355302), there is not a dominant strategy (even classical strategy) in the game and choosing the quantum strategy by each player can be the dominant strategy depending on the kind of strategy chosen by others. Since the entangled states of particles play an important role in the quantum game, finally we argue that the results of the players depend on the degree of entanglement in the initial state of the game. (paper)

  9. An alternative time marker for the study of the uniform and uniformly accelerated movements

    Directory of Open Access Journals (Sweden)

    Osmar Henrique Moura da Silva

    2003-01-01

    Full Text Available This work presents a type of time marker set up with materials of low cost for the study of uniform movements as well as those accelerated by gravitacional force. A mechanism used to measure its frequency is coupled to it in order to find the approximate value of the acceleration of the local gravity. The experiment, that is adapted to be used during a kinematics class, can also be presented by the students at a science fair, for being a stimulating factor as it involves the students’ participation in its construction.

  10. Modeling laser wakefield accelerators in a Lorentz boosted frame

    Energy Technology Data Exchange (ETDEWEB)

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grotec, D. P.

    2010-06-15

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high-frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing the frame of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  11. Modeling laser wakefield accelerators in a Lorentz boosted frame

    International Nuclear Information System (INIS)

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2010-01-01

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference (1) is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accommodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing the frame of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  12. Modeling laser wakefield accelerators in a Lorentz boosted frame

    Energy Technology Data Exchange (ETDEWEB)

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2010-09-15

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [1] is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing theframe of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  13. Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction.

    Science.gov (United States)

    Motaal, Abdallah G; Coolen, Bram F; Abdurrachim, Desiree; Castro, Rui M; Prompers, Jeanine J; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2013-04-01

    We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensing reconstruction. Key to our approach is that we exploit the stochastic nature of the retrospective triggering acquisition scheme to produce an undersampled and random k-t space filling that allows for compressed sensing reconstruction and acceleration. As a standard, a self-gated FLASH sequence with a total acquisition time of 10 min was used to produce single-slice Cine movies of seven mouse hearts with 90 frames per cardiac cycle. Two times (2×) and three times (3×) k-t space undersampled Cine movies were produced from 2.5- and 1.5-min data acquisitions, respectively. The accelerated 90-frame Cine movies of mouse hearts were successfully reconstructed with a compressed sensing algorithm. The movies had high image quality and the undersampling artifacts were effectively removed. Left ventricular functional parameters, i.e. end-systolic and end-diastolic lumen surface areas and early-to-late filling rate ratio as a parameter to evaluate diastolic function, derived from the standard and accelerated Cine movies, were nearly identical. Copyright © 2012 John Wiley & Sons, Ltd.

  14. Effects of acceleration through the Dirac sea

    International Nuclear Information System (INIS)

    Hacyan, S.

    1986-01-01

    The effects of acceleration through massive scalar and spin-1/2 fields are investigated. It is shown that the density-of-states factor in a uniformly accelerated frame takes a complicated form, but the energy spectrum exhibits a Bose-Einstein or Fermi-Dirac distribution function. In particular, the Dirac sea shows thermal-like effects

  15. BrainFrame: a node-level heterogeneous accelerator platform for neuron simulations

    Science.gov (United States)

    Smaragdos, Georgios; Chatzikonstantis, Georgios; Kukreja, Rahul; Sidiropoulos, Harry; Rodopoulos, Dimitrios; Sourdis, Ioannis; Al-Ars, Zaid; Kachris, Christoforos; Soudris, Dimitrios; De Zeeuw, Chris I.; Strydis, Christos

    2017-12-01

    Objective. The advent of high-performance computing (HPC) in recent years has led to its increasing use in brain studies through computational models. The scale and complexity of such models are constantly increasing, leading to challenging computational requirements. Even though modern HPC platforms can often deal with such challenges, the vast diversity of the modeling field does not permit for a homogeneous acceleration platform to effectively address the complete array of modeling requirements. Approach. In this paper we propose and build BrainFrame, a heterogeneous acceleration platform that incorporates three distinct acceleration technologies, an Intel Xeon-Phi CPU, a NVidia GP-GPU and a Maxeler Dataflow Engine. The PyNN software framework is also integrated into the platform. As a challenging proof of concept, we analyze the performance of BrainFrame on different experiment instances of a state-of-the-art neuron model, representing the inferior-olivary nucleus using a biophysically-meaningful, extended Hodgkin-Huxley representation. The model instances take into account not only the neuronal-network dimensions but also different network-connectivity densities, which can drastically affect the workload’s performance characteristics. Main results. The combined use of different HPC technologies demonstrates that BrainFrame is better able to cope with the modeling diversity encountered in realistic experiments while at the same time running on significantly lower energy budgets. Our performance analysis clearly shows that the model directly affects performance and all three technologies are required to cope with all the model use cases. Significance. The BrainFrame framework is designed to transparently configure and select the appropriate back-end accelerator technology for use per simulation run. The PyNN integration provides a familiar bridge to the vast number of models already available. Additionally, it gives a clear roadmap for extending the platform

  16. Charged particle and photon acceleration by wakefield plasma waves in non-uniform plasmas

    International Nuclear Information System (INIS)

    Bulanov, S.V.; Kirsanov, V.I.; Sakharov, A.S.; Pegoraro, F.

    1993-01-01

    We discuss the acceleration of charged particles and the upshift of the frequency of short wave packets of laser radiation. The acceleration and the upshift are caused by wake plasma waves excited by a strong laser pulse in a non-uniform plasma. We show that unlimited acceleration of charged particles is possible for specific spatial dependencies of the plasma density. In this unlimited acceleration regime, particles have a fixed phase relationship with respect to the plasma wave, while their energy increases with time. When the wave breaking limit is approached and surpassed, the efficiency of the acceleration of the charged particles and of the frequency upshift of the photons can be increased significantly. (author) 3 refs

  17. Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction

    NARCIS (Netherlands)

    Motaal, Abdallah G.; Coolen, Bram F.; Abdurrachim, Desiree; Castro, Rui M.; Prompers, Jeanine J.; Florack, Luc M. J.; Nicolay, Klaas; Strijkers, Gustav J.

    2013-01-01

    We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensi ng reconstruction. Key to our

  18. Coordinates system adapted to non-inertial frames in Minkowski spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Patricio; Dahia, F. [Universidade Federal de Campo Grande (UFCG), PB (Brazil)

    2011-07-01

    Full text: Static observers in curved spacetimes may interpret their proper acceleration as the opposite of a local gravitation Field (in the Newtonian sense). Based on this interpretation and the equivalence principle, we are led to investigate congruences of timelike curves in Minkowski spacetime whose acceleration field coincides with the acceleration field of static observers of curved spaces. The congruences give rise to non-inertial frames that are examined. Specifically we find, based on the locality principle, the embedding of simultaneity hypersurfaces adapted to the non-inertial frame in an explicit form for arbitrary acceleration fields. This work has motivated the fact that according to the principle of equivalence, it is expected that some physical features of gravity cam be mimicked by accelerated frames in Minkowski spacetime. The Rindler frame, which is adapted to a family of uniformly accelerated observers, is a famous example of a non-inertial system that simulates some characteristics of a black hole's geometry. This frame has been widely investigated in the literature and here we are going to start our discussion pointing out a peculiar aspect of the Rindler frame. It is related to the remarkable characteristic that the proper acceleration 'a' of Rindler observers, which is constant along their world lines, varies according to the law a = 1/ρ in relation to the observers, where ρ corresponds to the initial distance of the observers with respect to the origin of an inertial frame. This particular dependence of a ρ is connected to the behavior of static observers in Schwarzschild geometry in the vicinity of the horizon. Indeed, if ρ denotes the radial distance of an observer to the horizon, then, the proper acceleration the observers need in order to stay at rest in their position close to the horizon is proportional to 1/ρ. Therefore the Rindler congruence and the static Schwarzschild observers have the same acceleration field

  19. Coordinates system adapted to non-inertial frames in Minkowski spacetime

    International Nuclear Information System (INIS)

    Felix, Patricio; Dahia, F.

    2011-01-01

    Full text: Static observers in curved spacetimes may interpret their proper acceleration as the opposite of a local gravitation Field (in the Newtonian sense). Based on this interpretation and the equivalence principle, we are led to investigate congruences of timelike curves in Minkowski spacetime whose acceleration field coincides with the acceleration field of static observers of curved spaces. The congruences give rise to non-inertial frames that are examined. Specifically we find, based on the locality principle, the embedding of simultaneity hypersurfaces adapted to the non-inertial frame in an explicit form for arbitrary acceleration fields. This work has motivated the fact that according to the principle of equivalence, it is expected that some physical features of gravity cam be mimicked by accelerated frames in Minkowski spacetime. The Rindler frame, which is adapted to a family of uniformly accelerated observers, is a famous example of a non-inertial system that simulates some characteristics of a black hole's geometry. This frame has been widely investigated in the literature and here we are going to start our discussion pointing out a peculiar aspect of the Rindler frame. It is related to the remarkable characteristic that the proper acceleration 'a' of Rindler observers, which is constant along their world lines, varies according to the law a = 1/ρ in relation to the observers, where ρ corresponds to the initial distance of the observers with respect to the origin of an inertial frame. This particular dependence of a ρ is connected to the behavior of static observers in Schwarzschild geometry in the vicinity of the horizon. Indeed, if ρ denotes the radial distance of an observer to the horizon, then, the proper acceleration the observers need in order to stay at rest in their position close to the horizon is proportional to 1/ρ. Therefore the Rindler congruence and the static Schwarzschild observers have the same acceleration field a(ρ). However

  20. Accelerating particles in general relativity (stationary C-metric)

    International Nuclear Information System (INIS)

    Farhoosh, H.

    1979-01-01

    The purpose of this thesis is to study the physical and geometrical properties of uniformly accelerating particles in the general theory of relativity and it consists of four main parts. In the first part the structure of the Killing horizons in the static vacuum C-metric which represents the gravitational field of a uniformly accelerating Schwarzschild like particle (non-rotating and spherically symmetric) is studied. In the second part these results are generalized to include the effects of the rotation of the source. For small acceleration and small rotation this solution reveals the existance of three Killing horizons. Two the these horizons are the Schwarzschild and the Rindler surfaces which are mainly due to the mass and the acceleration of the particle, respectively. In part three the radial geodesic and non-geodesic motions in the static vacuum C-metric (non-rotating case) are investigated. The effect of the dragging of the inertial frame is also shown in this part. In part four the radiative behavior of the stationary charged C-metric representing the electro-gravitational field of a uniformly accelerating and rotating charged particle with magnetic monopole and the NUT-parameter are investigated. The physical quantities - the news function, mass loss, mass, charge and the multipole moments - are calculated. It is also shown in this part that the magnetic monopole in the presence of rotation and acceleration affects the electric charge

  1. Dynamics and symmetries of a field partitioned by an accelerated frame

    OpenAIRE

    Gerlach, Ulrich H.

    1999-01-01

    The canonical evolution and symmetry generators are exhibited for a Klein-Gordon (K-G) system which has been partitioned by an accelerated coordinate frame into a pair of subsystems. This partitioning of the K-G system is conveyed to the canonical generators by the eigenfunction property of the Minkowski Bessel (M-B) modes. In terms of the M-B degrees of freedom, which are unitarily related to those of the Minkowski plane waves, a near complete diagonalization of these generators can be reali...

  2. Minkowski spacetime does not apply to a homogeneously accelerating medium

    Science.gov (United States)

    Coleman, Brian

    Home and comoving inertial frame parameters of an individual point of an idealized medium of launch length L uniformly co-accelerating between identical fixed-thrust rockets, are well known. This is not the case with the varying inter-rocket radar periods and related implications regarding a changing 'noninertial own-length' Λ which differs from a front rocket's retrospective separation L from the simultaneously relatively moving rear rocket. On the other hand, the nonhomogeneous acceleration case involving every comoving frame's unchanging perception of a contrived 'rigor mortis' medium (so-called 'rigid motion' traditionally associated with 'Rindler coordinates') whereby Λ = L = L , constitutes the sole extended accelerating medium scenario where the entrenched Minkowski metric is actually applicable. Paraphrasing Wolfgang Pauli, not only is Minkowski spacetime not correct [in the general sense], it is not even wrong [in the restricted sense].

  3. Application of the Reduction of Scale Range in a Lorentz Boosted Frame to the Numerical Simulation of Particle Acceleration Devices

    International Nuclear Information System (INIS)

    Vay, J.-L.; Fawley, W.M.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2009-01-01

    It has been shown (1) that it may be computationally advantageous to perform computer simulations in a boosted frame for a certain class of systems: particle beams interacting with electron clouds, free electron lasers, and laser-plasma accelerators. However, even if the computer model relies on a covariant set of equations, it was also pointed out that algorithmic difficulties related to discretization errors may have to be overcome in order to take full advantage of the potential speedup (2) . In this paper, we focus on the analysis of the complication of data input and output in a Lorentz boosted frame simulation, and describe the procedures that were implemented in the simulation code Warp(3). We present our most recent progress in the modeling of laser wakefield acceleration in a boosted frame, and describe briefly the potential benefits of calculating in a boosted frame for the modeling of coherent synchrotron radiation.

  4. Pseudo-entanglement evaluated in noninertial frames

    International Nuclear Information System (INIS)

    Mehri-Dehnavi, Hossein; Mirza, Behrouz; Mohammadzadeh, Hosein; Rahimi, Robabeh

    2011-01-01

    Research highlights: → We study pseudo-entanglement in noninertial frames. → We examine different measures of entanglement and nonclassical correlation for the state. → We find the threshold for entanglement is changed in noninertial frames. → We also describe the behavior of local unitary classes of states in noninertial frames. - Abstract: We study quantum discord, in addition to entanglement, of bipartite pseudo-entanglement in noninertial frames. It is shown that the entanglement degrades from its maximum value in a stationary frame to a minimum value in an infinite accelerating frame. There is a critical region found in which, for particular cases, entanglement of states vanishes for certain accelerations. The quantum discord of pseudo-entanglement decreases by increasing the acceleration. Also, for a physically inaccessible region, entanglement and nonclassical correlation are evaluated and shown to match the corresponding values of the physically accessible region for an infinite acceleration.

  5. Uniformly accelerating charged particles. A threat to the equivalence principle

    International Nuclear Information System (INIS)

    Lyle, Stephen N.

    2008-01-01

    There has been a long debate about whether uniformly accelerated charges should radiate electromagnetic energy and how one should describe their worldline through a flat spacetime, i.e., whether the Lorentz-Dirac equation is right. There are related questions in curved spacetimes, e.g., do different varieties of equivalence principle apply to charged particles, and can a static charge in a static spacetime radiate electromagnetic energy? The problems with the LD equation in flat spacetime are spelt out in some detail here, and its extension to curved spacetime is discussed. Different equivalence principles are compared and some vindicated. The key papers are discussed in detail and many of their conclusions are significantly revised by the present solution. (orig.)

  6. Dose linearity and uniformity of a linear accelerator designed for implementation of multileaf collimation system-based intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Saw, Cheng B.; Li Sicong; Ayyangar, Komanduri M.; Yoe-Sein, Maung; Pillai, Susha; Enke, Charles A.; Celi, Juan C.

    2003-01-01

    The dose linearity and uniformity of a linear accelerator designed for multileaf collimation system- (MLC) based IMRT was studied as a part of commissioning and also in response to recently published data. The linear accelerator is equipped with a PRIMEVIEW, a graphical interface and a SIMTEC IM-MAXX, which is an enhanced autofield sequencer. The SIMTEC IM-MAXX sequencer permits the radiation beam to be 'ON' continuously while delivering intensity modulated radiation therapy subfields at a defined gantry angle. The dose delivery is inhibited when the electron beam in the linear accelerator is forced out of phase with the microwave power while the MLC configures the field shape of a subfield. This beam switching mechanism reduces the overhead time and hence shortens the patient treatment time. The dose linearity, reproducibility, and uniformity were assessed for this type of dose delivery mechanism. The subfields with monitor units ranged from 1 MU to 100 MU were delivered using 6 MV and 23 MV photon beams. The doses were computed and converted to dose per monitor unit. The dose linearity was found to vary within 2% for both 6 MV and 23 MV photon beam using high dose rate setting (300 MU/min) except below 2 MU. The dose uniformity was assessed by delivering 4 subfields to a Kodak X-OMAT TL film using identical low monitor units. The optical density was converted to dose and found to show small variation within 3%. Our results indicate that this linear accelerator with SIMTEC IM-MAXX sequencer has better dose linearity, reproducibility, and uniformity than had been reported

  7. Influence functionals and the accelerating detector

    International Nuclear Information System (INIS)

    Anglin, J.R.

    1993-01-01

    The influence functional is derived for a massive scalar field in the ground state, coupled to a uniformly accelerating DeWitt monopole detector in (D+1)-dimensional Minkowski space. This confirms the local nature of the Unruh effect, and provides an exact solution to the problem of the accelerating detector without invoking a nonstandard quantization. A directional detector is presented which is efficiently decohered by the scalar field vacuum, and which illustrates an important difference between the quantum mechanics of inertial and noninertial frames. From the results of these calculations, some comments are made regarding the possibility of establishing a quantum equivalence principle, so that the Hawking effect might be derived from the Unruh effect

  8. Laser plasma acceleration of electrons with multi-PW laser beams in the frame of CILEX

    Energy Technology Data Exchange (ETDEWEB)

    Cros, B., E-mail: brigitte.cros@u-psud.fr [LPGP, CNRS and Université Paris Sud, Orsay (France); Paradkar, B.S. [LPGP, CNRS and Université Paris Sud, Orsay (France); Davoine, X. [CEA DAM DIF, Arpajon F-91297 (France); Chancé, A. [CEA IRFU-SACM, Gif-Sur-Yvette (France); Desforges, F.G. [LPGP, CNRS and Université Paris Sud, Orsay (France); Dobosz-Dufrénoy, S. [CEA DSM-IRAMIS-SPAM, Gif-sur-Yvette (France); Delerue, N. [LAL, CNRS and Universit Paris Sud, Orsay (France); Ju, J.; Audet, T.L.; Maynard, G. [LPGP, CNRS and Université Paris Sud, Orsay (France); Lobet, M.; Gremillet, L. [CEA DAM DIF, Arpajon F-91297 (France); Mora, P. [CPhT, CNRS and Ecole Polytechnique, Palaiseau (France); Schwindling, J.; Delferrière, O. [CEA IRFU-SACM, Gif-Sur-Yvette (France); Bruni, C.; Rimbault, C.; Vinatier, T. [LAL, CNRS and Universit Paris Sud, Orsay (France); Di Piazza, A. [Max-Planck-Institut für Kernphysik, Heidelberg (Germany); Grech, M. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, Palaiseau (France); and others

    2014-03-11

    Laser plasma acceleration of electrons has progressed along with advances in laser technology. It is thus expected that the development in the near-future of multi-PW-class laser and facilities will enable a vast range of scientific opportunities for laser plasma acceleration research. On one hand, high peak powers can be used to explore the extremely high intensity regime of laser wakefield acceleration, producing for example large amounts of electrons in the GeV range or generating high energy photons. On the other hand, the available laser energy can be used in the quasi-linear regime to create accelerating fields in large volumes of plasma and study controlled acceleration in a plasma stage of externally injected relativistic particles, either electrons or positrons. In the frame of the Centre Interdisciplinaire de la Lumière EXtrême (CILEX), the Apollon-10P laser will deliver two beams at the 1 PW and 10 PW levels, in ultra-short (>15fs) pulses, to a target area dedicated to electron acceleration studies, such as the exploration of the non-linear regimes predicted theoretically, or multi-stage laser plasma acceleration.

  9. Accurate current synchronization trigger mode for multi-framing gated camera on YANG accelerator

    International Nuclear Information System (INIS)

    Jiang Xiaoguo; Huang Xianbin; Li Chenggang; Yang Libing; Wang Yuan; Zhang Kaizhi; Ye Yi

    2007-01-01

    The current synchronization trigger mode is important for Z-pinch experiments carried out on the YANG accelerator. The technology can solve the problem of low synchronization precision. The inherent delay time between the load current waveform and the experimental phenomenon can be adopted to obtain the synchronization trigger time. The correlative time precision about ns level can be achieved in this way. The photoelectric isolator and optical fiber are used in the synchronization trigger system to eliminate the electro-magnetic interference and many accurate measurements on the YANG accelerator can be realized. The application of this trigger mode to the multi-framing gated camera synchronization trigger system has done the trick. The evolution course of Z-pinch imploding plasma has been recorded with 3 ns exposure time and 10 ns interframing time. (authors)

  10. Maxwell-Faraday Stresses in Electromagnetic Fields and the Self-Force on a Uniformly Accelerating Point Charge

    Science.gov (United States)

    Rowland, D. R.

    2007-01-01

    The physical analysis of a uniformly accelerating point charge provides a rich problem to explore in advanced courses in electrodynamics and relativity since it brings together fundamental concepts in relation to electromagnetic radiation, Einstein's equivalence principle and the inertial mass of field energy in ways that reveal subtleties in each…

  11. Acceleration of Solar Energetic Particles at a Fast Traveling Shock in Non-uniform Coronal Conditions

    Science.gov (United States)

    Le Roux, J. A.; Arthur, A. D.

    2017-09-01

    Time-dependent solar energetic particle (SEP) acceleration is investigated at a fast, nearly parallel spherical traveling shock in the strongly non-uniform corona by solving the standard focused transport equation for SEPs and transport equations for parallel propagating Alfvén waves that form a set of coupled equations. This enables the modeling of self-excitation of Alfvén waves in the inertial range by SEPs ahead of the shock and its role in enhancing the efficiency of the diffusive shock acceleration (DSA) of SEPs in a self-regulatory fashion. Preliminary results suggest that, because of the highly non-uniform coronal conditions that the shock encounters, both DSA and wave excitation are highly time-dependent processes. Thus, DSA spectra of SEPs strongly deviate from the simple power-law prediction of standard steady-state DSA theory and initially strong wave excitation weakens rapidly. Consequently, the ability of DSA to produce high energy SEPs in the corona of ∼1 GeV, as observed in the strongest gradual SEP events, appears to be strongly curtailed at a fast nearly parallel shock, but further research is needed before final conclusions can be drawn.

  12. Effects of hyperbolic rotation in Minkowski space on the modeling of plasma accelerators in a Lorentz boosted frame

    International Nuclear Information System (INIS)

    Vay, J.-L.; Geddes, C. G. R.; Cormier-Michel, E.; Grote, D. P.

    2011-01-01

    The effects of hyperbolic rotation in Minkowski space resulting from the use of Lorentz boosted frames of calculation on laser propagation in plasmas are analyzed. Selection of a boost frame at the laser group velocity is shown to alter the laser spectrum, allowing the use of higher boost velocities. The technique is applied to simulations of laser driven plasma wakefield accelerators, which promise much smaller machines and whose development requires detailed simulations that challenge or exceed current capabilities. Speedups approaching the theoretical optima are demonstrated, producing the first direct simulations of stages up to 1 TeV. This is made possible by a million times speedup thanks to a frame boost with a relativistic factor γ b as high as 1300, taking advantage of the rotation to mitigate an instability that limited previous work.

  13. Distribution uniformity of laser-accelerated proton beams

    Science.gov (United States)

    Zhu, Jun-Gao; Zhu, Kun; Tao, Li; Xu, Xiao-Han; Lin, Chen; Ma, Wen-Jun; Lu, Hai-Yang; Zhao, Yan-Ying; Lu, Yuan-Rong; Chen, Jia-Er; Yan, Xue-Qing

    2017-09-01

    Compared with conventional accelerators, laser plasma accelerators can generate high energy ions at a greatly reduced scale, due to their TV/m acceleration gradient. A compact laser plasma accelerator (CLAPA) has been built at the Institute of Heavy Ion Physics at Peking University. It will be used for applied research like biological irradiation, astrophysics simulations, etc. A beamline system with multiple quadrupoles and an analyzing magnet for laser-accelerated ions is proposed here. Since laser-accelerated ion beams have broad energy spectra and large angular divergence, the parameters (beam waist position in the Y direction, beam line layout, drift distance, magnet angles etc.) of the beamline system are carefully designed and optimised to obtain a radially symmetric proton distribution at the irradiation platform. Requirements of energy selection and differences in focusing or defocusing in application systems greatly influence the evolution of proton distributions. With optimal parameters, radially symmetric proton distributions can be achieved and protons with different energy spread within ±5% have similar transverse areas at the experiment target. Supported by National Natural Science Foundation of China (11575011, 61631001) and National Grand Instrument Project (2012YQ030142)

  14. A reticle retrofit and dosimetric consideration for a linear accelerator.

    Science.gov (United States)

    Krithivas, V

    1996-01-01

    An imperfect reticle system in an accelerator causes uncertainties in source-skin distance (SSD), off-axis distance (OAD), isocenter, and so forth. A reticle was designed and fabricated, and its implications on x-ray and electron beam dosimetry were investigated. A new reticle frame was dimensioned to fit snugly in the accelerator. The frame was fabricated to carry a pair of adjustable cross wires and to allow the machine operation in the photon and electron modes. The impact of the cross wires on 6 MV photon and 5-10 MeV electron beam parameters such as dose rate (Gy/monitor unit), beam uniformity, surface dose, and so forth, were studied using suitable ion chambers and phantoms. The retrofitted system offered long-term mechanical stability leading to precise SSD, OAD, and isocenter measurements. Changes introduced by the cross wires on the 6 MV photon and 5-10 MeV electron beams are presented. Long-term stability of a reticle in an accelerator is important for an accurate patient setup and for making reliable dosimetric measurements. Beam characteristrics have to be studied whenever modifications on a reticle system are made.

  15. Minkowski spacetime does not apply to a homogeneously accelerating medium

    Directory of Open Access Journals (Sweden)

    Brian Coleman

    Full Text Available Home and comoving inertial frame parameters of an individual point of an idealized medium of launch length L uniformly co-accelerating between identical fixed-thrust rockets, are well known. This is not the case with the varying inter-rocket radar periods and related implications regarding a changing ‘noninertial own-length’ Λ which differs from a front rocket’s retrospective separation L from the simultaneously relatively moving rear rocket. On the other hand, the nonhomogeneous acceleration case involving every comoving frame’s unchanging perception of a contrived ‘rigor mortis’ medium (so-called ‘rigid motion’ traditionally associated with ‘Rindler coordinates’ whereby Λ=L=L, constitutes the sole extended accelerating medium scenario where the entrenched Minkowski metric is actually applicable. Paraphrasing Wolfgang Pauli, not only is Minkowski spacetime not correct [in the general sense], it is not even wrong [in the restricted sense]. Keywords: Homogeneous acceleration, Radar intervals, Minkowski metric, Rigor mortis acceleration, Medium-timed photon crossing rate, Retrospective separation

  16. Application of the reduction of scale range in a Lorentz boosted frame to the numerical simulation of particle acceleration devices

    International Nuclear Information System (INIS)

    Vay, J.; Fawley, W.M.; Geddes, C.G.; Cormier-Michel, E.; Grote, D.P.

    2009-01-01

    It has been shown that the ratio of longest to shortest space and time scales of a system of two or more components crossing at relativistic velocities is not invariant under Lorentz transformation. This implies the existence of a frame of reference minimizing an aggregate measure of the ratio of space and time scales. It was demonstrated that this translated into a reduction by orders of magnitude in computer simulation run times, using methods based on first principles (e.g., Particle-In-Cell), for particle acceleration devices and for problems such as: free electron laser, laser-plasma accelerator, and particle beams interacting with electron clouds. Since then, speed-ups ranging from 75 to more than four orders of magnitude have been reported for the simulation of either scaled or reduced models of the above-cited problems. In it was shown that to achieve full benefits of the calculation in a boosted frame, some of the standard numerical techniques needed to be revised. The theory behind the speed-up of numerical simulation in a boosted frame, latest developments of numerical methods, and example applications with new opportunities that they offer are all presented

  17. Grassmannian frames with applications to coding and communication

    OpenAIRE

    Strohmer, Thomas; Heath Jr., Robert W

    2003-01-01

    For a given class ${\\cal F}$ of uniform frames of fixed redundancy we define a Grassmannian frame as one that minimizes the maximal correlation $||$ among all frames $\\{f_k\\}_{k \\in {\\cal I}} \\in {\\cal F}$. We first analyze finite-dimensional Grassmannian frames. Using links to packings in Grassmannian spaces and antipodal spherical codes we derive bounds on the minimal achievable correlation for Grassmannian frames. These...

  18. APT/LEDA RFQ and support frame structural analysis

    International Nuclear Information System (INIS)

    Ellis, S.

    1997-01-01

    This report documents structural analysis of the Accelerator Production of Tritium Low Energy Demonstration Accelerator (APT/LEDA) Radio Frequency Quadrupole (RFQ) accelerator structure and its associated support frame. This work was conducted for the Department of Energy in support of the APT/LEDA. Structural analysis of the RFQ was performed to quantify stress levels and deflections due to both vacuum loading and gravity loading. This analysis also verified the proposed support scheme geometry and quantified interface loads. This analysis also determined the necessary stiffness and strength requirements of the RFQ support frame verifying the conceptual design geometry and allowing specification of individual frame elements. Complete structural analysis of the frame was completed subsequently. This report details structural analysis of the RFQ assembly with regard to gravity and vacuum loads only. Thermally induced stresses from the Radio Frequency (RF) surface resistance heating were not considered

  19. Open quantum systems in noninertial frames

    International Nuclear Information System (INIS)

    Khan, Salman; Khan, M K

    2011-01-01

    We study the effects of decoherence on the entanglement generated by the Unruh effect in noninertial frames by using phase flip, phase damping and depolarizing channels. It is shown that decoherence strongly influences the initial state entanglement. Entanglement sudden death can occur irrespective of the acceleration of the noninertial frame under the action of phase flip and phase damping channels. It is investigated that an early sudden death occurs for large acceleration under the depolarizing environment. Moreover, entanglement increases for a highly decohered phase flip channel.

  20. On the interaction between media frames and individual frames of the Israeli-Palestinian conflict

    Directory of Open Access Journals (Sweden)

    Wilhelm Kempf

    2012-10-01

    Full Text Available The present paper reports on a media effects research experiment in which six groups of participants were asked to read and evaluate differently framed news articles about two scenarios: a Palestinian attack on Israel and an Israeli military operation against Palestinians. The experimental results show that media peace frames of violent events in the Israeli-Palestinian conflict are generally regarded by the German public as more comprehensible, less biased, more balanced and less partisan than media war frames of the same events. The specific ways in which recipients respond to the frames, however, depend on their prior knowledge of the conflict, on their positioning to the conflict and on their sensitivity to the ambivalence of war and peace for both Israel and the Palestinians. This supports the hypothesis that neither news selection nor framing have uniform effects on public opinion.

  1. On the prestressing and deformation of rectangular particle detector frames

    International Nuclear Information System (INIS)

    Margulies, S.

    1978-01-01

    Particle detectors such as spark chambers and multiwire proportional chambers (MWPC) generally contain planar electrodes stretched across rectangular frames. For detectors of reasonable size, this can result in fairly large forces acting on the frames. To maintain the electrode planes under uniform tension and to prevent sagging, the frames must be prestressed. This paper contains a detailed examination of the deformation of rectangular frames under stress. A simple model for this phenomenon is presented. The model consists of treating each side of the frame as an elastic beam subject to the condition that the sides remain perpendicular at the corners. The predictions of the model are in good agreement with measured deflections of a MWPC frame. The model is used to determine the optimum value of a single concentrated prestressing force F to best approximate the total distributed force W of a uniformly tensed electrode plane. For most geometries it is found that F is about 62% of W. (Auth.)

  2. On The Dynamic Analysis of Non-Uniform Beams Under Uniformly ...

    African Journals Online (AJOL)

    ... the non-uniform continuous beam was replaced by a non-continuous (discrete) system made up of beam elements. The modified elemental and overall stiffness, and mass matrices, the elemental and overall centripetal acceleration matrices as well as the load vector were derived. Next, the Newmark's direct integration ...

  3. Continuous-variable entanglement sharing in noninertial frames

    International Nuclear Information System (INIS)

    Adesso, Gerardo; Fuentes-Schuller, Ivette; Ericsson, Marie

    2007-01-01

    We study the distribution of entanglement between modes of a free scalar field from the perspective of observers in uniform acceleration. We consider a two-mode squeezed state of the field from an inertial perspective, and analytically study the degradation of entanglement due to the Unruh effect, in the cases of either one or both observers undergoing uniform acceleration. We find that, for two observers undergoing finite acceleration, the entanglement vanishes between the lowest-frequency modes. The loss of entanglement is precisely explained as a redistribution of the inertial entanglement into multipartite quantum correlations among accessible and inaccessible modes from a noninertial perspective. We show that classical correlations are also lost from the perspective of two accelerated observers but conserved if one of the observers remains inertial

  4. Affine and quasi-affine frames for rational dilations

    DEFF Research Database (Denmark)

    Bownik, Marcin; Lemvig, Jakob

    2011-01-01

    In this paper we extend the investigation of quasi-affine systems, which were originally introduced by Ron and Shen [J. Funct. Anal. 148 (1997), 408-447] for integer, expansive dilations, to the class of rational, expansive dilations. We show that an affine system is a frame if, and only if......, the corresponding family of quasi-affine systems are frames with uniform frame bounds. We also prove a similar equivalence result between pairs of dual affine frames and dual quasi-affine frames. Finally, we uncover some fundamental differences between the integer and rational settings by exhibiting an example...

  5. Reynolds Stress Closure for Inertial Frames and Rotating Frames

    Science.gov (United States)

    Petty, Charles; Benard, Andre

    2017-11-01

    In a rotating frame-of-reference, the Coriolis acceleration and the mean vorticity field have a profound impact on the redistribution of kinetic energy among the three components of the fluctuating velocity. Consequently, the normalized Reynolds (NR) stress is not objective. Furthermore, because the Reynolds stress is defined as an ensemble average of a product of fluctuating velocity vector fields, its eigenvalues must be non-negative for all turbulent flows. These fundamental properties (realizability and non-objectivity) of the NR-stress cannot be compromised in computational fluid dynamic (CFD) simulations of turbulent flows in either inertial frames or in rotating frames. The recently developed universal realizable anisotropic prestress (URAPS) closure for the NR-stress depends explicitly on the local mean velocity gradient and the Coriolis operator. The URAPS-closure is a significant paradigm shift from turbulent closure models that assume that dyadic-valued operators associated with turbulent fluctuations are objective.

  6. Canceling the momentum in a phase-shifting algorithm to eliminate spatially uniform errors.

    Science.gov (United States)

    Hibino, Kenichi; Kim, Yangjin

    2016-08-10

    In phase-shifting interferometry, phase modulation nonlinearity causes both spatially uniform and nonuniform errors in the measured phase. Conventional linear-detuning error-compensating algorithms only eliminate the spatially variable error component. The uniform error is proportional to the inertial momentum of the data-sampling weight of a phase-shifting algorithm. This paper proposes a design approach to cancel the momentum by using characteristic polynomials in the Z-transform space and shows that an arbitrary M-frame algorithm can be modified to a new (M+2)-frame algorithm that acquires new symmetry to eliminate the uniform error.

  7. Do framing effects reveal irrational choice?

    Science.gov (United States)

    Mandel, David R

    2014-06-01

    Framing effects have long been viewed as compelling evidence of irrationality in human decision making, yet that view rests on the questionable assumption that numeric quantifiers used to convey the expected values of choice options are uniformly interpreted as exact values. Two experiments show that when the exactness of such quantifiers is made explicit by the experimenter, framing effects vanish. However, when the same quantifiers are given a lower bound (at least) meaning, the typical framing effect is found. A 3rd experiment confirmed that most people spontaneously interpret the quantifiers in standard framing tests as lower bounded and that their interpretations strongly moderate the framing effect. Notably, in each experiment, a significant majority of participants made rational choices, either choosing the option that maximized expected value (i.e., lives saved) or choosing consistently across frames when the options were of equal expected value. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  8. Acceleration of the charged particles due to chaotic scattering in the combined black hole gravitational field and asymptotically uniform magnetic field

    International Nuclear Information System (INIS)

    Stuchlik, Zdenek; Kolos, Martin

    2016-01-01

    To test the role of large-scale magnetic fields in accretion processes, we study the dynamics of the charged test particles in the vicinity of a black hole immersed into an asymptotically uniform magnetic field. Using the Hamiltonian formalism of the charged particle dynamics, we examine chaotic scattering in the effective potential related to the black hole gravitational field combined with the uniform magnetic field. Energy interchange between the translational and oscillatory modes of the charged particle dynamics provides a mechanism for charged particle acceleration along the magnetic field lines. This energy transmutation is an attribute of the chaotic charged particle dynamics in the combined gravitational and magnetic fields only, the black hole rotation is not necessary for such charged particle acceleration. The chaotic scatter can cause a transition to the motion along the magnetic field lines with small radius of the Larmor motion or vanishing Larmor radius, when the speed of the particle translational motion is largest and it can be ultra-relativistic. We discuss the consequences of the model of ionization of test particles forming a neutral accretion disc, or heavy ions following off-equatorial circular orbits, and we explore the fate of heavy charged test particles after ionization where no kick of heavy ions is assumed and only the switch-on effect of the magnetic field is relevant. We demonstrate that acceleration and escape of the ionized particles can be efficient along the Kerr black hole symmetry axis parallel to the magnetic field lines. We show that a strong acceleration of the ionized particles to ultra-relativistic velocities is preferred in the direction close to the magnetic field lines. Therefore, the process of ionization of Keplerian discs around the Kerr black holes can serve as a model of relativistic jets. (orig.)

  9. Acceleration of the charged particles due to chaotic scattering in the combined black hole gravitational field and asymptotically uniform magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Stuchlik, Zdenek; Kolos, Martin [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Opava (Czech Republic)

    2016-01-15

    To test the role of large-scale magnetic fields in accretion processes, we study the dynamics of the charged test particles in the vicinity of a black hole immersed into an asymptotically uniform magnetic field. Using the Hamiltonian formalism of the charged particle dynamics, we examine chaotic scattering in the effective potential related to the black hole gravitational field combined with the uniform magnetic field. Energy interchange between the translational and oscillatory modes of the charged particle dynamics provides a mechanism for charged particle acceleration along the magnetic field lines. This energy transmutation is an attribute of the chaotic charged particle dynamics in the combined gravitational and magnetic fields only, the black hole rotation is not necessary for such charged particle acceleration. The chaotic scatter can cause a transition to the motion along the magnetic field lines with small radius of the Larmor motion or vanishing Larmor radius, when the speed of the particle translational motion is largest and it can be ultra-relativistic. We discuss the consequences of the model of ionization of test particles forming a neutral accretion disc, or heavy ions following off-equatorial circular orbits, and we explore the fate of heavy charged test particles after ionization where no kick of heavy ions is assumed and only the switch-on effect of the magnetic field is relevant. We demonstrate that acceleration and escape of the ionized particles can be efficient along the Kerr black hole symmetry axis parallel to the magnetic field lines. We show that a strong acceleration of the ionized particles to ultra-relativistic velocities is preferred in the direction close to the magnetic field lines. Therefore, the process of ionization of Keplerian discs around the Kerr black holes can serve as a model of relativistic jets. (orig.)

  10. Quantum bit commitment with misaligned reference frames

    International Nuclear Information System (INIS)

    Harrow, Aram; Oliveira, Roberto; Terhal, Barbara M.

    2006-01-01

    Suppose that Alice and Bob define their coordinate axes differently, and the change of reference frame between them is given by a probability distribution μ over SO(3). We show that this uncertainty of reference frame is of no use for bit commitment when μ is uniformly distributed over a (sub)group of SO(3), but other choices of μ can give rise to a partially or even arbitrarily secure bit commitment

  11. Mechanical Effects of the Non-Uniform Current Distribution on HTS Coils for Accelerators Wound with REBCO Roebel Cable

    CERN Document Server

    Murtomaeki, Jaako; Kirby, Glen; Rossi, Lucio; Ruuskanen, Janne; Stenvall, Antti; Murtomaeki, Jaako

    2017-01-01

    Future high-energy accelerators will need very high magnetic fields in the range of 20 T. The EuCARD-2 WP10 Future Magnets collaboration is aiming at testing HTS-based Roebel cables in an accelerator magnet. The demonstrator should produce around 17 T, when inserted into the 100 mm aperture of Feather-M2 13 T outsert magnet. HTS Roebel cables are assembled from meander shaped REBCO coated conductor tapes. In comparison with fair level of uniformity of current distribution in cables made out of round Nb-Ti or Nb$_{3}$Sn strands, current distribution within the coils wound from Roebel cables is highly non-homogeneous. It results in nonuniform electromagnetic force distribution over the cable that could damage the very thin REBCO superconducting layer. This paper focuses on the numerical models to describe the effect of the non-homogenous current distribution on stress distribution in the demonstrator magnet designed for the EuCARD-2 project. Preliminary results indicate that the impregnation bonding betweenthe...

  12. Frame and frameless linear accelerator-based radiosurgery for idiopathic trigeminal neuralgia.

    Science.gov (United States)

    Chen, Allan Y; Hsieh, Yen; McNair, Steffanie; Li, Qijuan; Xu, Kevin Y; Pappas, Conrad

    2015-01-01

    We report outcome of linear accelerator (Linac)-based stereotactic radiosurgery (SRS) for trigeminal neuralgia (TGN) utilizing rigid head frame (RF) and facemask (FM) immobilization.Method: From November 2008 to October 2012, 48 patients with idiopathic TGN underwent primary SRS by a dedicated Linac. RF immobilization was utilized for 34 patients, and frameless image-guided radiosurgery (IGRS) with FM immobilization was performed in 14 patients. Treatment outcome was assessed by patient interviews with a 7-item questionnaire. Sub-millimeter targeting accuracy (0.71±0.31 mm) was recorded for frameless IGRS by a novel hidden-target phantom method. With a follow-up of 26 months, significant pain relief was recorded in 43 (89%) patients, including 26 (54%) complete and 17 (35%) partial responses; with a significant reduction of 2.4±1.3 points ( p < 0.01) on the 5-point Barrow Neurological Institute pain scale. No significant pain relief difference ( p = 0.23) was detected between patients immobilized by RF and FM. Notable pin site problems were reported in 9 (26%) of 34 patients immobilized by RF. Frameless IGRS with FM immobilization is more patient friendly and can achieve as excellent treatment outcome as with RF immobilization for idiopathic TGN.

  13. Low-emittance uniform density Cs+ sources for heavy ion fusion accelerators studies

    International Nuclear Information System (INIS)

    Eylon, S.; Henestroza, E.; Garvey, T.; Johnson, R.; Chupp, W.

    1991-04-01

    Low-emittance (high-brightness) Cs + thermionic sources were developed for the heavy ion induction linac experiment MBE-4 at LBL. The MBE-4 linac accelerates four 10 mA beams from 200 ke V to 900 ke V while amplifying the current up to a factor of nine. Recent studies of the transverse beam dynamics suggested that characteristics of the injector geometry were contributing to the normalized transverse emissions growth. Phase-space and current density distribution measurements of the beam extracted from the injector revealed overfocusing of the outermost rays causing a hollow density profile. We shall report on the performance of a 5 mA scraped beam source (which eliminates the outermost beam rays in the diode) and on the design of an improved 10 mA source. The new source is based on EGUN calculations which indicated that a beam with good emissions and uniform current density could be obtained by modifying the cathode Pierce electrodes and using a spherical emitting surface. The measurements of the beam current density profile on a test stand were found to be in agreement with the numerical simulations. 3 refs., 6 figs

  14. Aerodynamics in arbitrarily accelerating frames: application to high-g turns

    CSIR Research Space (South Africa)

    Gledhill, Irvy MA

    2010-09-01

    Full Text Available Fifth-generation missilies accelerate up to 100 g in turns, and higher accelerations are expected as agility increases. The authors have developed the theory of aerodynamics for arbitrary accelerations, and have validated modelling in a...

  15. Aerodynamics in arbitrarily accelerating frames: application to high-g turns

    CSIR Research Space (South Africa)

    Gledhill, Irvy MA

    2010-09-01

    Full Text Available Fifth-generation missiles accelerate up to 100 g in turns, and higher accelerations are expected as agility increases. The auhtors have developed the theory of aerodynamics for arbitrary accelerations, and have validated modelling in a Computational...

  16. Quantum teleportation via noisy bipartite and tripartite accelerating quantum states: beyond the single mode approximation

    Science.gov (United States)

    Zounia, M.; Shamirzaie, M.; Ashouri, A.

    2017-09-01

    In this paper quantum teleportation of an unknown quantum state via noisy maximally bipartite (Bell) and maximally tripartite (Greenberger-Horne-Zeilinger (GHZ)) entangled states are investigated. We suppose that one of the observers who would receive the sent state accelerates uniformly with respect to the sender. The interactions of the quantum system with its environment during the teleportation process impose noises. These (unital and nonunital) noises are: phase damping, phase flip, amplitude damping and bit flip. In expressing the modes of the Dirac field used as qubits, in the accelerating frame, the so-called single mode approximation is not imposed. We calculate the fidelities of teleportation, and discuss their behaviors using suitable plots. The effects of noise, acceleration and going beyond the single mode approximation are discussed. Although the Bell states bring higher fidelities than GHZ states, the global behaviors of the two quantum systems with respect to some noise types, and therefore their fidelities, are different.

  17. Frames and operator theory in analysis and signal processing

    CERN Document Server

    Larson, David R; Nashed, Zuhair; Nguyen, Minh Chuong; Papadakis, Manos

    2008-01-01

    This volume contains articles based on talks presented at the Special Session Frames and Operator Theory in Analysis and Signal Processing, held in San Antonio, Texas, in January of 2006. Recently, the field of frames has undergone tremendous advancement. Most of the work in this field is focused on the design and construction of more versatile frames and frames tailored towards specific applications, e.g., finite dimensional uniform frames for cellular communication. In addition, frames are now becoming a hot topic in mathematical research as a part of many engineering applications, e.g., matching pursuits and greedy algorithms for image and signal processing. Topics covered in this book include: Application of several branches of analysis (e.g., PDEs; Fourier, wavelet, and harmonic analysis; transform techniques; data representations) to industrial and engineering problems, specifically image and signal processing. Theoretical and applied aspects of frames and wavelets. Pure aspects of operator theory empha...

  18. Design of large-format X-ray framing image tube

    International Nuclear Information System (INIS)

    Zong Fangke; Yang Qinlao; Gu Li; Li Xiang; Zhang Jingjin

    2012-01-01

    An implementation method of large-format framing image tube is proposed. An electrostatic focusing image tube with large input photocathode and small output image is designed. Coupling with common small-format microchannel plate (MCP) gated framing unit, image gating and enhancement can be realized. Compared to the tube with large-format MCP, this kind of framing tube avoids the high manufacturing cost of lager-format MCP and overcomes the transmission voltage loss and gain uniformity caused by long micro strips. The framing image tube has an effective input working diameter of 100 mm, an output image diameter of 40 mm, and a magnification of 0.4. The centre spatial resolution is 14.4 lp/mm, the marginal spatial resolution is 11.2 lp/mm, and the the geometric distortion is less than 15%. The framing characteristics is determined by the MCP framing unit. This method is an effective way for expanding the work area of framing image tubes. (authors)

  19. Multiplier convergent series and uniform convergence of mapping ...

    Indian Academy of Sciences (India)

    MS received 14 April 2011; revised 17 November 2012. Abstract. In this paper, we introduce the frame property of complex sequence sets and study the uniform convergence of nonlinear mapping series in β-dual of spaces consisting of multiplier convergent series. Keywords. Multiplier convergent series; mapping series. 1.

  20. Graphics processing unit accelerated intensity-based optical coherence tomography angiography using differential frames with real-time motion correction.

    Science.gov (United States)

    Watanabe, Yuuki; Takahashi, Yuhei; Numazawa, Hiroshi

    2014-02-01

    We demonstrate intensity-based optical coherence tomography (OCT) angiography using the squared difference of two sequential frames with bulk-tissue-motion (BTM) correction. This motion correction was performed by minimization of the sum of the pixel values using axial- and lateral-pixel-shifted structural OCT images. We extract the BTM-corrected image from a total of 25 calculated OCT angiographic images. Image processing was accelerated by a graphics processing unit (GPU) with many stream processors to optimize the parallel processing procedure. The GPU processing rate was faster than that of a line scan camera (46.9 kHz). Our OCT system provides the means of displaying structural OCT images and BTM-corrected OCT angiographic images in real time.

  1. Optimization of a space spectrograph main frame and frequency response analysis of the frame

    Science.gov (United States)

    Zhang, Xin-yu; Chen, Zhi-yuan; Yang, Shi-mo

    2009-07-01

    A space spectrograph main structure is optimized and examined in order to satisfy the space operational needs. The space spectrograph will be transported into its operational orbit by the launch vehicle and it will undergo dynamic environment in the spacecraft injection period. The unexpected shocks may cause declination of observation accuracy and even equipment damages. The main frame is one of the most important parts because its mechanical performance has great influence on the operational life of the spectrograph, accuracy of observation, etc. For the reason of cost reduction and stability confirming, lower weight and higher structure stiffness of the frame are simultaneously required. Structure optimization was conducted considering the initial design modal analysis results. The base modal frequency raised 10.34% while the whole weight lowered 8.63% compared to the initial design. The purpose of this study is to analyze the new design of main frame mechanical properties and verify whether it can satisfy strict optical demands under the dynamic impact during spacecraft injection. For realizing and forecasting the frequency response characteristics of the main structure in mechanical environment experiment, dynamic analysis of the structure should be performed simulating impulse loads from the bottom base. Therefore, frequency response analysis (FRA) of the frame was then performed using the FEA software MSC.PATRAN/NASTRAN. Results of shock response spectrum (SRS) responses from the base excitations were given. Stress and acceleration dynamic responses of essential positions in the spacecraft injection course were also calculated and spectrometer structure design was examined considering stiffness / strength demands. In this simulation, maximum stresses of Cesic material in two acceleration application cases are 45.1 and 74.1 MPa, respectively. They are all less than yield strengths. As is demonstrated from the simulation, strength reservation of the frame is

  2. Plasma physics in noninertial frames

    International Nuclear Information System (INIS)

    Thyagaraja, A.; McClements, K. G.

    2009-01-01

    Equations describing the nonrelativistic motion of a charged particle in an arbitrary noninertial reference frame are derived from the relativistically invariant form of the particle action. It is shown that the equations of motion can be written in the same form in inertial and noninertial frames, with the effective electric and magnetic fields in the latter modified by inertial effects associated with centrifugal and Coriolis accelerations. These modifications depend on the particle charge-to-mass ratio, and also the vorticity, specific kinetic energy, and compressibility of the frame flow. The Newton-Lorentz, Vlasov, and Fokker-Planck equations in such a frame are derived. Reduced models such as gyrokinetic, drift-kinetic, and fluid equations are then derivable from these equations in the appropriate limits, using standard averaging procedures. The results are applied to tokamak plasmas rotating about the machine symmetry axis with a nonrelativistic but otherwise arbitrary toroidal flow velocity. Astrophysical applications of the analysis are also possible since the power of the action principle is such that it can be used to describe relativistic flows in curved spacetime.

  3. Uniformity of cylindrical imploding underwater shockwaves at very small radii

    Science.gov (United States)

    Yanuka, D.; Rososhek, A.; Bland, S. N.; Krasik, Ya. E.

    2017-11-01

    We compare the convergent shockwaves generated from underwater, cylindrical arrays of copper wire exploded by multiple kilo-ampere current pulses on nanosecond and microsecond scales. In both cases, the pulsed power devices used for the experiments had the same stored energy (˜500 J) and the wire mass was adjusted to optimize energy transfer to the shockwave. Laser backlit framing images of the shock front were achieved down to the radius of 30 μm. It was found that even in the case of initial azimuthal non-symmetry, the shock wave self-repairs in the final stages of its motion, leading to a highly uniform implosion. In both these and previous experiments, interference fringes have been observed in streak and framing images as the shockwave approached the axis. We have been able to accurately model the origin of the fringes, which is due to the propagation of the laser beam diffracting off the uniform converging shock front. The dynamics of the shockwave and its uniformity at small radii indicate that even with only 500 J stored energies, this technique should produce pressures above 1010 Pa on the axis, with temperatures and densities ideal for warm dense matter research.

  4. High-speed two-frame gated camera for parameters measurement of Dragon-Ⅰ LIA

    International Nuclear Information System (INIS)

    Jiang Xiaoguo; Wang Yuan; Zhang Kaizhi; Shi Jinshui; Deng Jianjun; Li Jin

    2012-01-01

    The time-resolved measurement system which can work at very high speed is necessary in electron beam parameter diagnosis for Dragon-Ⅰ linear induction accelerator (LIA). A two-frame gated camera system has been developed and put into operation. The camera system adopts the optical principle of splitting the imaging light beam into two parts in the imaging space of a lens with long focus length. It includes lens coupled gated image intensifier, CCD camera, high speed shutter trigger device based on large scale field programmable gate array. The minimum exposure time for each image is about 3 ns, and the interval time between two images can be adjusted with a step of about 0.5 ns. The exposure time and the interval time can be independently adjusted and can reach about 1 s. The camera system features good linearity, good response uniformity, equivalent background illumination (EBI) as low as about 5 electrons per pixel per second, large adjustment range of sensitivity, and excel- lent flexibility and adaptability in applications. The camera system can capture two frame images at one time with the image size of 1024 x 1024. It meets the requirements of measurement for Dragon-Ⅰ LIA. (authors)

  5. Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy

    International Nuclear Information System (INIS)

    Thatar Vento, V.; Bergueiro, J.; Cartelli, D.; Valda, A.A.; Kreiner, A.J.

    2011-01-01

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam.

  6. Damage Localization and Quantification of Earthquake Excited RC-Frames

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    1998-01-01

    or three series of ground motions of increasing magnitude. After each of these runs the damage state of the frame was examined and each storey of the frame were classified into one of the following six classifications: undamaged, cracked, lightly damaged, damaged, severely damaged or collapse. During each...... of the ground motion events the storey accelerations were measured by accelerometers. After application of the last earthquake sequence to the structure the frames were cut into pieces and each of the beams and columns was statically tested and damage assessment was performed using the obtained stiffnesses...

  7. Formation and acceleration of uniformly filled ellipsoidal electron bunches obtained via space-charge-driven expansion from a cesium-telluride photocathode

    Directory of Open Access Journals (Sweden)

    P. Piot

    2013-01-01

    Full Text Available We report the experimental generation, acceleration, and characterization of a uniformly filled electron bunch obtained via space-charge-driven expansion (often referred to as “blow-out regime” in an L-band (1.3-GHz radiofrequency photoinjector. The beam is photoemitted from a cesium-telluride semiconductor photocathode using a short (<200  fs ultraviolet laser pulse. The produced electron bunches are characterized with conventional diagnostics and the signatures of their ellipsoidal character are observed. We especially demonstrate the production of ellipsoidal bunches with charges up to ∼0.5  nC corresponding to a ∼20-fold increase compared to previous experiments with metallic photocathodes.

  8. Lack of political diversity and the framing of findings in personality and clinical psychology.

    Science.gov (United States)

    Lilienfeld, Scott O

    2015-01-01

    I extend the arguments of Duarte et al. by examining the implications of political uniformity for the framing of findings in personality and clinical psychology. I argue that the one-sided framing of psychological research on political ideology has limited our understanding of the personality correlates of liberalism and conservatism.

  9. Frames and semi-frames

    International Nuclear Information System (INIS)

    Antoine, Jean-Pierre; Balazs, Peter

    2011-01-01

    Loosely speaking, a semi-frame is a generalized frame for which one of the frame bounds is absent. More precisely, given a total sequence in a Hilbert space, we speak of an upper (resp. lower) semi-frame if only the upper (resp. lower) frame bound is valid. Equivalently, for an upper semi-frame, the frame operator is bounded, but has an unbounded inverse, whereas a lower semi-frame has an unbounded frame operator, with a bounded inverse. We study mostly upper semi-frames, both in the continuous and discrete case, and give some remarks for the dual situation. In particular, we show that reconstruction is still possible in certain cases.

  10. Preconditioning Filter Bank Decomposition Using Structured Normalized Tight Frames

    Directory of Open Access Journals (Sweden)

    Martin Ehler

    2015-01-01

    Full Text Available We turn a given filter bank into a filtering scheme that provides perfect reconstruction, synthesis is the adjoint of the analysis part (so-called unitary filter banks, all filters have equal norm, and the essential features of the original filter bank are preserved. Unitary filter banks providing perfect reconstruction are induced by tight generalized frames, which enable signal decomposition using a set of linear operators. If, in addition, frame elements have equal norm, then the signal energy is spread through the various filter bank channels in some uniform fashion, which is often more suitable for further signal processing. We start with a given generalized frame whose elements allow for fast matrix vector multiplication, as, for instance, convolution operators, and compute a normalized tight frame, for which signal analysis and synthesis still preserve those fast algorithmic schemes.

  11. Illumination non-uniformity of spirally wobbling beam in heavy ion fusion

    International Nuclear Information System (INIS)

    Suzuki, T.; Noguchi, K.; Kurosaki, T.; Barada, D.; Kawata, S.; Ma, Y. Y.; Ogoyski, A.I.

    2016-01-01

    In inertial confinement fusion, the driver beam illumination non-uniformity leads a degradation of fusion energy output. The illumination non-uniformity allowed is less than a few percent in inertial fusion target implosion. Heavy ion beam (HIB) accelerator provides a capability to oscillate a beam axis with a high frequency. The wobbling beams may provide a new method to reduce or smooth the beam illumination non-uniformity. In this paper the HIBs wobbling illumination scheme was optimized. (paper)

  12. Spin transport in non-inertial frame

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Debashree, E-mail: debashreephys@gmail.com; Basu, B., E-mail: sribbasu@gmail.com

    2014-09-01

    The influence of acceleration and rotation on spintronic applications is theoretically investigated. In our formulation, considering a Dirac particle in a non-inertial frame, different spin related aspects are studied. The spin current appearing due to the inertial spin–orbit coupling (SOC) is enhanced by the interband mixing of the conduction and valence band states. Importantly, one can achieve a large spin current through the k{sup →}.p{sup →} method in this non-inertial frame. Furthermore, apart from the inertial SOC term due to acceleration, for a particular choice of the rotation frequency, a new kind of SOC term can be obtained from the spin rotation coupling (SRC). This new kind of SOC is of Dresselhaus type and controllable through the rotation frequency. In the field of spintronic applications, utilizing the inertial SOC and SRC induced SOC term, theoretical proposals for the inertial spin filter, inertial spin galvanic effect are demonstrated. Finally, one can tune the spin relaxation time in semiconductors by tuning the non-inertial parameters.

  13. Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy.

    Science.gov (United States)

    Vento, V Thatar; Bergueiro, J; Cartelli, D; Valda, A A; Kreiner, A J

    2011-12-01

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Entanglement concentration for two-mode Gaussian states in non-inertial frames

    International Nuclear Information System (INIS)

    Di Noia, Maurizio; Giraldi, Filippo; Petruccione, Francesco

    2017-01-01

    Entanglement creation and concentration by means of a beam splitter (BS) is analysed for a generic two-mode bipartite Gaussian state in a relativistic framework. The total correlations, the purity and the entanglement in terms of logarithmic negativity are analytically studied for observers in an inertial state and in a non-inertial state of uniform acceleration. The dependence of entanglement on the BS transmissivity due to the Unruh effect is analysed in the case when one or both observers undergo uniform acceleration. Due to the Unruh effect, depending on the initial Gaussian state parameters and observed accelerations, the best condition for entanglement generation limited to the two modes of the observers in their regions is not always a balanced beam splitter, as it is for the inertial case. (paper)

  15. Work and Inertial Frames

    Science.gov (United States)

    Kaufman, Richard

    2017-12-01

    A fairly recent paper resolves a large discrepancy in the internal energy utilized to fire a cannon as calculated by two inertial observers. Earth and its small reaction velocity must be considered in the system so that the change in kinetic energy is calculated correctly. This paper uses a car in a similar scenario, but considers the work done by forces acting over distances. An analysis of the system must include all energy interactions, including the work done on the car and especially the (negative) work done on Earth in a moving reference frame. This shows the importance of considering the force on Earth and the distance Earth travels. For calculation of work in inertial reference frames, the center of mass perspective is shown to be useful. We also consider the energy requirements to efficiently accelerate a mass among interacting masses.

  16. High brightness electron accelerator

    International Nuclear Information System (INIS)

    Sheffield, R.L.; Carlsten, B.E.; Young, L.M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of accelerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electrons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electrons as the electrons enter the first cavity. 5 figs

  17. Apparatus for uniform pumping of lasing media

    International Nuclear Information System (INIS)

    Condit, W.C.; Eccles, S.F.

    1975-01-01

    Electron beam pumping of gaseous or liquid lasing media is carried out by means of electron pulses generated by an electron accelerator. Between the accelerator and the laser cavity, the electron pulse is subjected to a magnetic field to turn the electron pulse approximately through a quarter orbit, so that in essence the direction of pulse travel is changed from axial to lateral. This procedure then enables pumping of the laser cavity uniformly and simultaneously, or in any desired traveling wave mode, over the entire length of the laser cavity with relatively short, and highly intense, electron pulses. (U.S.)

  18. Adaptive wavelet tight frame construction for accelerating MRI reconstruction

    Directory of Open Access Journals (Sweden)

    Genjiao Zhou

    2017-09-01

    Full Text Available The sparsity regularization approach, which assumes that the image of interest is likely to have sparse representation in some transform domain, has been an active research area in image processing and medical image reconstruction. Although various sparsifying transforms have been used in medical image reconstruction such as wavelet, contourlet, and total variation (TV etc., the efficiency of these transforms typically rely on the special structure of the underlying image. A better way to address this issue is to develop an overcomplete dictionary from the input data in order to get a better sparsifying transform for the underlying image. However, the general overcomplete dictionaries do not satisfy the so-called perfect reconstruction property which ensures that the given signal can be perfectly represented by its canonical coefficients in a manner similar to orthonormal bases, resulting in time consuming in the iterative image reconstruction. This work is to develop an adaptive wavelet tight frame method for magnetic resonance image reconstruction. The proposed scheme incorporates the adaptive wavelet tight frame approach into the magnetic resonance image reconstruction by solving a l0-regularized minimization problem. Numerical results show that the proposed approach provides significant time savings as compared to the over-complete dictionary based methods with comparable performance in terms of both peak signal-to-noise ratio and subjective visual quality.

  19. Quantum algebraic representation of localization and motion of a Dirac electron

    International Nuclear Information System (INIS)

    Jaekel, Marc-Thierry; Reynaud, Serge

    2001-01-01

    Quantum algebraic observables representing localization in space-time of a Dirac electron are defined. Inertial motion of the electron is represented in the quantum algebra with electron mass acting as the generator of motion. Since transformations to uniformly accelerated frames are naturally included in this conformally invariant description, the quantum algebra is also able to deal with uniformly accelerated motion

  20. Probabilistic uniformities of uniform spaces

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Lopez, J.; Romaguera, S.; Sanchis, M.

    2017-07-01

    The theory of metric spaces in the fuzzy context has shown to be an interesting area of study not only from a theoretical point of view but also for its applications. Nevertheless, it is usual to consider these spaces as classical topological or uniform spaces and there are not too many results about constructing fuzzy topological structures starting from a fuzzy metric. Maybe, H/{sup o}hle was the first to show how to construct a probabilistic uniformity and a Lowen uniformity from a probabilistic pseudometric /cite{Hohle78,Hohle82a}. His method can be directly translated to the context of fuzzy metrics and allows to characterize the categories of probabilistic uniform spaces or Lowen uniform spaces by means of certain families of fuzzy pseudometrics /cite{RL}. On the other hand, other different fuzzy uniformities can be constructed in a fuzzy metric space: a Hutton $[0,1]$-quasi-uniformity /cite{GGPV06}; a fuzzifiying uniformity /cite{YueShi10}, etc. The paper /cite{GGRLRo} gives a study of several methods of endowing a fuzzy pseudometric space with a probabilistic uniformity and a Hutton $[0,1]$-quasi-uniformity. In 2010, J. Guti/'errez Garc/'{/i}a, S. Romaguera and M. Sanchis /cite{GGRoSanchis10} proved that the category of uniform spaces is isomorphic to a category formed by sets endowed with a fuzzy uniform structure, i. e. a family of fuzzy pseudometrics satisfying certain conditions. We will show here that, by means of this isomorphism, we can obtain several methods to endow a uniform space with a probabilistic uniformity. Furthermore, these constructions allow to obtain a factorization of some functors introduced in /cite{GGRoSanchis10}. (Author)

  1. Ultra-accelerated natural sunlight exposure testing

    Science.gov (United States)

    Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  2. Acceleration of planes segmentation using normals from previous frame

    Science.gov (United States)

    Gritsenko, Pavel; Gritsenko, Igor; Seidakhmet, Askar; Abduraimov, Azizbek

    2017-12-01

    One of the major problem in integration process of robots is to make them able to function in a human environment. In terms of computer vision, the major feature of human made rooms is the presence of planes [1, 2, 20, 21, 23]. In this article, we will present an algorithm dedicated to increase speed of a plane segmentation. The algorithm uses information about location of a plane and its normal vector to speed up the segmentation process in the next frame. In conjunction with it, we will address such aspects of ICP SLAM as performance and map representation.

  3. Remarks on Hawking radiation as tunneling from a uniformly ...

    Indian Academy of Sciences (India)

    Abstract. Motivated by the Hamilton–Jacobi method of Angheben et al, we investigate the Hawking tunneling radiation from a uniformly accelerating rectilinear black hole for which the horizons and entropy are functions of θ. After several coordinate transforma- tions, we conclude that when the self-gravitational interaction ...

  4. Dosimetry for electron beam from Microtron accelerator using chemical dosimeters

    International Nuclear Information System (INIS)

    Joseph, Praveen; Nairy, Rajesha; Sanjeev, Ganesh; Narayana, Y.

    2014-01-01

    The Microtron is a simple, compact, low cost electron accelerator with excellent beam quality and it can accelerate electrons to relativistic energies. The variable energy Microtron at Mangalore University is used for R and D programmes in basic and applied areas of physics, chemistry, materials science, biological sciences, medical science and industry. While studying the effects of radiation, it is essential to have complete knowledge of absorbed dose. In the present study the absorbed dose and the uniformity of dose distribution at various points due to 8 MeV electron beam from Microtron accelerator has been calculated using different chemical dosimeters. From the dosimetry studies for Microtron accelerator, it is observed that the absorbed doses measured at various dose ranges from 2 Gy to 25 kGy using FBX dosimeters at very low doses, Fricke at intermediate doses and alanine and glutamine at higher doses, varied linearly with increasing electron counts. From the dosimetry studies it is observed that there is a linear relation between dose and electron numbers over a wide range of absorbed doses. It is evaluated that the electron counts of about 1.15 x 10 14 corresponds to an absorbed dose of 100 Gy. Fricke dosimetry was carried out to measure the uniformity in dose distribution at a distance of 30 cm from the beam exit window of the accelerator to ensure the availability of uniform irradiation field size. It is observed that a field size of about 4 x 4 cm is available at 30 cm distance from the beam exit window over which the dose distribution is uniform. The sample size during radiological studies using Microtron was restricted to less than 4 x 4 cm dimension at 30 cm distance from the beam exit window to ensure uniform dose distribution to the sample

  5. Electron accelerator technology research in food irradiation

    International Nuclear Information System (INIS)

    Jin Jianqiao; Ye Mingyang; Zhang Yue; Yang Bin; Xu Tao; Kong Xiangshan

    2014-01-01

    Electronic accelerator was applied to instead of cobalt sources for food irradiation, to keep food quality and to improve the effect of the treatment. Appropriate accelerator parameters lead to optimal technique. The irradiation effect is associated with the relationship between uniformity and irradiating speed, the effect of cargo size on radiation penetration, as well as other factors that affect the irradiation effects. Industrialization of electron accelerator irradiation will be looked to the future. (authors)

  6. Airy Wave Packets Accelerating in Space-Time

    Science.gov (United States)

    Kondakci, H. Esat; Abouraddy, Ayman F.

    2018-04-01

    Although diffractive spreading is an unavoidable feature of all wave phenomena, certain waveforms can attain propagation invariance. A lesser-explored strategy for achieving optical self-similar propagation exploits the modification of the spatiotemporal field structure when observed in reference frames moving at relativistic speeds. For such an observer, it is predicted that the associated Lorentz boost can bring to a halt the axial dynamics of a wave packet of an arbitrary profile. This phenomenon is particularly striking in the case of a self-accelerating beam—such as an Airy beam—whose peak normally undergoes a transverse displacement upon free propagation. Here we synthesize an acceleration-free Airy wave packet that travels in a straight line by deforming its spatiotemporal spectrum to reproduce the impact of a Lorentz boost. The roles of the axial spatial coordinate and time are swapped, leading to "time diffraction" manifested in self-acceleration observed in the propagating Airy wave-packet frame.

  7. A cyclotron resonance laser accelerator

    International Nuclear Information System (INIS)

    Sprangle, P.; Tang, C.M.; Vlahos, L.

    1983-01-01

    A laser acceleration mechanism which utilizes a strong static, almost uniform, magnetic field together with an intense laser pulse is analyzed. The interaction and acceleration mechanism relies on a self resonance effect. Since the laser field is assumed to be diffraction limited, the magnetic field must be spatially varied to maintain resonance. The effective accelerating gradient is shown to scale like 1/√E /SUB b/ , where E /SUB b/ is the electron energy. For a numerical illustration the authors consider a 1 x 10 13 W/cm 2 , CO 2 laser and show that electrons can be accelerated to more than 500 MeV in a distance of 15 m (approximately two Rayleigh lengths)

  8. Test Particles with Acceleration-Dependent Lagrangian

    OpenAIRE

    Toller, M.

    2005-01-01

    We consider a classical test particle subject to electromagnetic and gravitational fields, described by a Lagrangian depending on the acceleration and on a fundamental length. We associate to the particle a moving local reference frame and we study its trajectory in the principal fibre bundle of all the Lorentz frames. We discuss in this framework the general form of the Lagrange equations and the connection between symmetries and conservation laws (Noether theorem). We apply these results to...

  9. Nonlinear Analysis of Frame Structures Subjected to Blast Overpressures

    Science.gov (United States)

    1977-05-01

    columns have the same plastic bending capacity., CIMp . 16 •,, vi In most cases, more economical designs of blast-resistant frames are realized when...3 HH+(w-I)L’] ~~~(-IE r3+H((201A)I-~L COMBINED MECHANISM L+2n 2C ccW CP CIMP R n Number of bay* a ,2,3... w =Uniform ___________L ____ equivalent *For

  10. Framing the frame

    Directory of Open Access Journals (Sweden)

    Todd McElroy

    2007-08-01

    Full Text Available We examined how the goal of a decision task influences the perceived positive, negative valence of the alternatives and thereby the likelihood and direction of framing effects. In Study 1 we manipulated the goal to increase, decrease or maintain the commodity in question and found that when the goal of the task was to increase the commodity, a framing effect consistent with those typically observed in the literature was found. When the goal was to decrease, a framing effect opposite to the typical findings was observed whereas when the goal was to maintain, no framing effect was found. When we examined the decisions of the entire population, we did not observe a framing effect. In Study 2, we provided participants with a similar decision task except in this situation the goal was ambiguous, allowing us to observe participants' self-imposed goals and how they influenced choice preferences. The findings from Study 2 demonstrated individual variability in imposed goal and provided a conceptual replication of Study 1. %need keywords

  11. Electron cyclotron harmonic wave acceleration

    Science.gov (United States)

    Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

  12. Electron cyclotron harmonic wave acceleration

    International Nuclear Information System (INIS)

    Karimabadi, H.; Menyuk, C.R.; Sprangle, P.; Vlahos, L.; Salonika Univ., Greece)

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts. 31 references

  13. Integration of Reference Frames Using VLBI

    Science.gov (United States)

    Ma, Chopo; Smith, David E. (Technical Monitor)

    2001-01-01

    Very Long Baseline Interferometry (VLBI) has the unique potential to integrate the terrestrial and celestial reference frames through simultaneous estimation of positions and velocities of approx. 40 active VLBI stations and a similar number of stations/sites with sufficient historical data, the position and position stability of approx. 150 well-observed extragalactic radio sources and another approx. 500 sources distributed fairly uniformly on the sky, and the time series of the five parameters that specify the relative orientation of the two frames. The full realization of this potential is limited by a number of factors including the temporal and spatial distribution of the stations, uneven distribution of observations over the sources and the sky, variations in source structure, modeling of the solid/fluid Earth and troposphere, logistical restrictions on the daily observing network size, and differing strategies for optimizing analysis for TRF, for CRF and for EOP. The current status of separately optimized and integrated VLBI analysis will be discussed.

  14. Quantum mechanics in noninertial reference frames: Violations of the nonrelativistic equivalence principle

    International Nuclear Information System (INIS)

    Klink, W.H.; Wickramasekara, S.

    2014-01-01

    In previous work we have developed a formulation of quantum mechanics in non-inertial reference frames. This formulation is grounded in a class of unitary cocycle representations of what we have called the Galilean line group, the generalization of the Galilei group that includes transformations amongst non-inertial reference frames. These representations show that in quantum mechanics, just as is the case in classical mechanics, the transformations to accelerating reference frames give rise to fictitious forces. A special feature of these previously constructed representations is that they all respect the non-relativistic equivalence principle, wherein the fictitious forces associated with linear acceleration can equivalently be described by gravitational forces. In this paper we exhibit a large class of cocycle representations of the Galilean line group that violate the equivalence principle. Nevertheless the classical mechanics analogue of these cocycle representations all respect the equivalence principle. -- Highlights: •A formulation of Galilean quantum mechanics in non-inertial reference frames is given. •The key concept is the Galilean line group, an infinite dimensional group. •A large class of general cocycle representations of the Galilean line group is constructed. •These representations show violations of the equivalence principle at the quantum level. •At the classical limit, no violations of the equivalence principle are detected

  15. Framing the frame

    OpenAIRE

    Todd McElroy; John J. Seta

    2007-01-01

    We examined how the goal of a decision task influences the perceived positive, negative valence of the alternatives and thereby the likelihood and direction of framing effects. In Study 1 we manipulated the goal to increase, decrease or maintain the commodity in question and found that when the goal of the task was to increase the commodity, a framing effect consistent with those typically observed in the literature was found. When the goal was to decrease, a framing effect opposite to the ty...

  16. Innovations in rocking wall-frame systems-theory and development

    Science.gov (United States)

    Grigorian, Mark; Tavousi, Shayan

    2017-09-01

    The need to improve the seismic performance of buildings has brought about innovative systems such as rocking wall-moment frame (RWMF) combinations. The behavior of RWMFs can best be visualized by the moment-frame (MF) restraining the wall in place, and the rigid rocking wall (RRW) providing additional damping and imposing uniform drift along the height of the frame. A novel method of analysis followed by the development of a new lateral resisting system is introduced. The proposed concepts lead to an efficient structural configuration with provisions for self-centering, reparability, performance control, damage tolerance and collapse prevention. Exact, unique, closed form formulae have been provided to assess the collapse prevention and self-centering capabilities of the system. The objective is to provide an informative account of RWMF behavior for preliminary design as well as educational purposes. All formulae have been verified by independent computer analysis. Parametric examples have been provided to verify the validity of the proposed solutions.

  17. Acceleration Measurements Using Smartphone Sensors: Dealing with the Equivalence Principle

    OpenAIRE

    Monteiro, Martín; Cabeza, Cecilia; Martí, Arturo C.

    2014-01-01

    Acceleration sensors built into smartphones, i-pads or tablets can conveniently be used in the physics laboratory. By virtue of the equivalence principle, a sensor fixed in a non-inertial reference frame cannot discern between a gravitational field and an accelerated system. Accordingly, acceleration values read by these sensors must be corrected for the gravitational component. A physical pendulum was studied by way of example, and absolute acceleration and rotation angle values were derived...

  18. Hardware accelerator design for tracking in smart camera

    Science.gov (United States)

    Singh, Sanjay; Dunga, Srinivasa Murali; Saini, Ravi; Mandal, A. S.; Shekhar, Chandra; Vohra, Anil

    2011-10-01

    Smart Cameras are important components in video analysis. For video analysis, smart cameras needs to detect interesting moving objects, track such objects from frame to frame, and perform analysis of object track in real time. Therefore, the use of real-time tracking is prominent in smart cameras. The software implementation of tracking algorithm on a general purpose processor (like PowerPC) could achieve low frame rate far from real-time requirements. This paper presents the SIMD approach based hardware accelerator designed for real-time tracking of objects in a scene. The system is designed and simulated using VHDL and implemented on Xilinx XUP Virtex-IIPro FPGA. Resulted frame rate is 30 frames per second for 250x200 resolution video in gray scale.

  19. A space vehicle rotating with a uniform angu- lar velocity about a ...

    Indian Academy of Sciences (India)

    IAS Admin

    A space vehicle rotating with a uniform angu- lar velocity about a vertical axis fixed to it is falling freely vertically downwards, say, with its engine shut off. It carries two astronauts inside it. One astronaut throws a tiny tool towards the other astronaut. The motion of the tiny tool with reference to a rotating frame rigidly fixed.

  20. Discovery of Uniformly Expanding Universe

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2012-01-01

    Full Text Available Saul Perlmutter and the Brian Schmidt – Adam Riess teams reported that their Friedmann-model GR-based analysis of their supernovae magnitude-redshift data re- vealed a new phenomenon of “dark energy” which, it is claimed, forms 73% of the energy / matter density of the present-epoch universe, and which is linked to the further claim of an accelerating expansion of the universe. In 2011 Perlmutter, Schmidt and Riess received the Nobel Prize in Physics “for the discovery of the accelerating ex- pansion of the Universe through observations of distant supernovae”. Here it is shown that (i a generic model-independent analysis of this data reveals a uniformly expanding universe, (ii their analysis actually used Newtonian gravity, and finally (iii the data, as well as the CMB fluctuation data, does not require “dark energy” nor “dark matter”, but instead reveals the phenomenon of a dynamical space, which is absent from the Friedmann model.

  1. Dynamic response characteristics of steel portal frames having semi-rigid joints under sinusoidal wave excitation

    Science.gov (United States)

    Bhatti, Abdul Qadir

    2017-12-01

    To demonstrate the characteristics of the nonlinear response of steel frames, an elastic dynamic response analysis of the semi-rigid frame is performed under the harmonic wave. The semi-rigid contact is represented by the alternating spring which is given stiffness by a three-parameter energy model which approaches the hysterical curve by hardening model. The properties of spectra and hysteric curves are presented. This study shows that (1) the greater the acceleration input capacitance the smaller the instant connection capability and the smaller is the response. (2) However, by allowing an extreme increase in capacitance input acceleration, response spectra can be increased as the contact stiffness results near zero.

  2. Transforming in-situ observations of CME-driven shock accelerated protons into the shock's reference frame.

    Directory of Open Access Journals (Sweden)

    I. M. Robinson

    2005-07-01

    Full Text Available We examine the solar energetic particle event following solar activity from 14, 15 April 2001 which includes a "bump-on-the-tail" in the proton energy spectra at 0.99 AU from the Sun. We find this population was generated by a CME-driven shock which arrived at 0.99 AU around midnight 18 April. As such this population represents an excellent opportunity to study in isolation, the effects of proton acceleration by the shock. The peak energy of the bump-on-the-tail evolves to progressively lower energies as the shock approaches the observing spacecraft at the inner Lagrange point. Focusing on the evolution of this peak energy we demonstrate a technique which transforms these in-situ spectral observations into a frame of reference co-moving with the shock whilst making allowance for the effects of pitch angle scattering and focusing. The results of this transform suggest the bump-on-the-tail population was not driven by the 15 April activity but was generated or at least modulated by a CME-driven shock which left the Sun on 14 April. The existence of a bump-on-the-tail population is predicted by models in Rice et al. (2003 and Li et al. (2003 which we compare with observations and the results of our analysis in the context of both the 14 April and 15 April CMEs. We find an origin of the bump-on-the-tail at the 14 April CME-driven shock provides better agreement with these modelled predictions although some discrepancy exists as to the shock's ability to accelerate 100 MeV protons.

    Keywords. Solar physics, astrophysics and astronomy (Energetic particles; Flares and mass ejections – Space plasma physics (Transport processes

  3. Dynamics of entanglement under decoherence in noninertial frames

    International Nuclear Information System (INIS)

    Shi Jia-Dong; Wu Tao; Song Xue-Ke; Ye Liu

    2014-01-01

    In this paper, we investigate the entanglement dynamics of a two-qubit entangled state coupled with its noisy environment, and plan to utilize weak measurement and quantum reversal measurement to study the entanglement dynamics under different decoherence channels in noninertial frames. Through the calculations and analyses, it is shown that the weak measurement can prevent entanglement from coupling to the amplitude damping channel, while the system is under the phase damping and flip channels. This protection protocol cannot prevent entanglement but will accelerate the death of entanglement. In addition, if the system is in the noninertial reference frame, then the effect of weak measurement will be weakened for the amplitude damping channel. Nevertheless, for other decoherence channels, the Unruh effect does not affect the quantum weak measurement, the only exception is that the maximum value of entanglement is reduced to √2/2 of the original value in the inertial frames. (general)

  4. Remotely detected vehicle mass from engine torque-induced frame twisting

    Science.gov (United States)

    McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Sweeney, Glenn D.

    2017-06-01

    Determining the mass of a vehicle from ground-based passive sensor data is important for many traffic safety requirements. This work presents a method for calculating the mass of a vehicle using ground-based video and acoustic measurements. By assuming that no energy is lost in the conversion, the mass of a vehicle can be calculated from the rotational energy generated by the vehicle's engine and the linear acceleration of the vehicle over a period of time. The amount of rotational energy being output by the vehicle's engine can be calculated from its torque and angular velocity. This model relates remotely observed, engine torque-induced frame twist to engine torque output using the vehicle's suspension parameters and engine geometry. The angular velocity of the engine is extracted from the acoustic emission of the engine, and the linear acceleration of the vehicle is calculated by remotely observing the position of the vehicle over time. This method combines these three dynamic signals; engine induced-frame twist, engine angular velocity, and the vehicle's linear acceleration, and three vehicle specific scalar parameters, into an expression that describes the mass of the vehicle. This method was tested on a semitrailer truck, and the results demonstrate a correlation of 97.7% between calculated and true vehicle mass.

  5. Role of neutrino mixing in accelerated proton decay

    Science.gov (United States)

    Blasone, M.; Lambiase, G.; Luciano, G. G.; Petruzziello, L.

    2018-05-01

    The decay of accelerated protons has been analyzed both in the laboratory frame (where the proton is accelerated) and in the comoving frame (where the proton is at rest and interacts with the Fulling-Davies-Unruh thermal bath of electrons and neutrinos). The equality between the two rates has been exhibited as an evidence of the necessity of Fulling-Davies-Unruh effect for the consistency of quantum field theory formalism. Recently, it has been argued that neutrino mixing can spoil such a result, potentially opening new scenarios in neutrino physics. In the present paper, we analyze in detail this problem, and we find that, assuming flavor neutrinos to be fundamental and working within a certain approximation, the agreement can be restored.

  6. Some relationship between G-frames and frames

    Directory of Open Access Journals (Sweden)

    Mehdi Rashidi-Kouchi

    2015-06-01

    Full Text Available In this paper we proved that every g-Riesz basis for Hilbert space $H$ with respect to $K$ by adding a condition is a Riesz basis for Hilbert $B(K$-module $B(H,K$. This is an extension of [A. Askarizadeh,M. A. Dehghan, {em G-frames as special frames}, Turk. J. Math., 35, (2011 1-11]. Also, we derived similar results for g-orthonormal and orthogonal bases. Some relationships between dual frame, dual g-frame and exact frame and exact g-frame are presented too.

  7. Analytic mappings: a new approach in particle production by accelerated observers

    International Nuclear Information System (INIS)

    Sanchez, N.

    1982-01-01

    This is a summary of the authors recent results about physical consequences of analytic mappings in the space-time. Classically, the mapping defines an accelerated frame. At the quantum level it gives rise to particle production. Statistically, the real singularities of the mapping have associated temperatures. This concerns a new approach in Q.F.T. as formulated in accelerated frames. It has been considered as a first step in the understanding of the deep connection that could exist between the structure (geometry and topology) of the space-time and thermodynamics, mainly motivated by the works of Hawking since 1975. (Auth.)

  8. Seismic Rehabilitation of RC Frames by Using Steel Panels

    Science.gov (United States)

    Mowrtage, Waiel

    2008-07-01

    Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the seismic performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame. To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base accelerations. The amplitudes of base accelerations were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The seismic performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme.

  9. Seismic Rehabilitation of RC Frames by Using Steel Panels

    International Nuclear Information System (INIS)

    Mowrtage, Waiel

    2008-01-01

    Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the seismic performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame.To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base accelerations. The amplitudes of base accelerations were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The seismic performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme

  10. Sporadic frame dropping impact on quality perception

    Science.gov (United States)

    Pastrana-Vidal, Ricardo R.; Gicquel, Jean Charles; Colomes, Catherine; Cherifi, Hocine

    2004-06-01

    Over the past few years there has been an increasing interest in real time video services over packet networks. When considering quality, it is essential to quantify user perception of the received sequence. Severe motion discontinuities are one of the most common degradations in video streaming. The end-user perceives a jerky motion when the discontinuities are uniformly distributed over time and an instantaneous fluidity break is perceived when the motion loss is isolated or irregularly distributed. Bit rate adaptation techniques, transmission errors in the packet networks or restitution strategy could be the origin of this perceived jerkiness. In this paper we present a psychovisual experiment performed to quantify the effect of sporadically dropped pictures on the overall perceived quality. First, the perceptual detection thresholds of generated temporal discontinuities were measured. Then, the quality function was estimated in relation to a single frame dropping for different durations. Finally, a set of tests was performed to quantify the effect of several impairments distributed over time. We have found that the detection thresholds are content, duration and motion dependent. The assessment results show how quality is impaired by a single burst of dropped frames in a 10 sec sequence. The effect of several bursts of discarded frames, irregularly distributed over the time is also discussed.

  11. Noise frame duration, masking potency and whiteness of temporal noise.

    Science.gov (United States)

    Kukkonen, Heljä; Rovamo, Jyrki; Donner, Kristian; Tammikallio, Marja; Raninen, Antti

    2002-09-01

    Because of the limited contrast range, increasing the duration of the noise frame is often the only option for increasing the masking potency of external, white temporal noise. This, however, reduces the high-frequency cutoff beyond which noise is no longer white. This study was conducted to determine the longest noise frame duration that produces the strongest masking effect and still mimics white noise on the detection of sinusoidal flicker. Contrast energy thresholds (E(th)) were measured for flicker at 1.25 to 20 Hz in strong, purely temporal (spatially uniform), additive, external noise. The masking power of white external noise, characterized by its spectral density at zero frequency N0, increases with the duration of the noise frame. For short noise frame durations, E(th) increased in direct proportion to N0, keeping the nominal signal-to-noise ratio [SNR = (E(th)/N0)(0.5)] constant at threshold. The masking effect thus increased with the duration of the noise frame and the noise mimicked white noise. When noise frame duration and N0 increased further, the nominal SNR at threshold started to decrease, indicating that noise no longer mimicked white noise. The minimum number of noise frames per flicker cycle needed to mimic white noise decreased with increasing flicker frequency from 8.3 at 1.25 Hz to 1.6 at 20 Hz. The critical high-frequency cutoff of detection-limiting temporal noise in terms of noise frames per signal cycle depends on the temporal frequency of the signal. This is opposite to the situation in the spatial domain and must be taken into consideration when temporal signals are masked with temporal noise.

  12. High speed photography of the plasma flow and the projectiles in the T.U.M. hypervelocity accelerator

    International Nuclear Information System (INIS)

    Igenbergs, E.; Kuczera, H.; Schroeder, B.

    1979-01-01

    The hypervelocity accelerator at the Technische Universitaet Muenchen, FRG, accelerates small projectiles (0.1 to 1.0 mm diameter) to velocities around 20 km/s. The photographic equipment consists of two Cordin single-frame image converter cameras and one TRW image converter camera with streak units and multiple-frame units. They are used for plasma flow diagnostics and the measurement of the position and the velocity of the projectiles. The single-frame cameras are triggered with a Laser light bar and the photographic measurement of the projectile velocity will be compared with Doppler-Radar. (author)

  13. Fermat's Principle of Least Time in the Presence of Uniformly Moving Boundaries and Media

    Science.gov (United States)

    Gjurchinovski, Aleksandar; Skeparovski, Aleksandar

    2007-01-01

    The refraction of a light ray by a homogeneous, isotropic and non-dispersive transparent material half-space in uniform rectilinear motion is investigated theoretically. The approach is an amalgamation of the original Fermat's principle and the fact that an isotropic optical medium at rest becomes optically anisotropic in a frame where the medium…

  14. Development of an Emergency Locking Unit for a Belt-In-Seat (BIS System Using a MEMS Acceleration Sensor

    Directory of Open Access Journals (Sweden)

    Chang Hyun Baek

    2010-04-01

    Full Text Available This paper proposes an emergency locking unit (ELU for a seat belt retractor which is mounted on the back frame of a vehicle seat. The proposed unit uses a recliner sensor based on a MEMS acceleration sensor and solenoid mechanism. The seat has an upper frame supported to tilt on a lower frame. The retractor in belt in seat (BIS system is supported by the upper frame. The proposed recliner sensor based on a MEMS acceleration sensor comprises orientation means for maintaining a predetermined orientation of emergency relative to the lower frame independently of the force of gravity when the upper frame tilts on the lower frame. Experimental results show that the developed recliner sensor unit operates effectively with respect to rollover angles. Thus, the developed unit will have a considerable potential to offer a new design concept in BIS system.

  15. Characterizing ground motions that collapse steel special moment-resisting frames or make them unrepairable

    Science.gov (United States)

    Olsen, Anna H.; Heaton, Thomas H.; Hall, John F.

    2015-01-01

    This work applies 64,765 simulated seismic ground motions to four models each of 6- or 20-story, steel special moment-resisting frame buildings. We consider two vector intensity measures and categorize the building response as “collapsed,” “unrepairable,” or “repairable.” We then propose regression models to predict the building responses from the intensity measures. The best models for “collapse” or “unrepairable” use peak ground displacement and velocity as intensity measures, and the best models predicting peak interstory drift ratio, given that the frame model is “repairable,” use spectral acceleration and epsilon (ϵ) as intensity measures. The more flexible frame is always more likely than the stiffer frame to “collapse” or be “unrepairable.” A frame with fracture-prone welds is substantially more susceptible to “collapse” or “unrepairable” damage than the equivalent frame with sound welds. The 20-story frames with fracture-prone welds are more vulnerable to P-delta instability and have a much higher probability of collapse than do any of the 6-story frames.

  16. Seismic performance evaluation of an infilled rocking wall frame structure through quasi-static cyclic testing

    Science.gov (United States)

    Pan, Peng; Wu, Shoujun; Wang, Haishen; Nie, Xin

    2018-04-01

    Earthquake investigations have illustrated that even code-compliant reinforced concrete frames may suffer from soft-story mechanism. This damage mode results in poor ductility and limited energy dissipation. Continuous components offer alternatives that may avoid such failures. A novel infilled rocking wall frame system is proposed that takes advantage of continuous component and rocking characteristics. Previous studies have investigated similar systems that combine a reinforced concrete frame and a wall with rocking behavior used. However, a large-scale experimental study of a reinforced concrete frame combined with a rocking wall has not been reported. In this study, a seismic performance evaluation of the newly proposed infilled rocking wall frame structure was conducted through quasi-static cyclic testing. Critical joints were designed and verified. Numerical models were established and calibrated to estimate frame shear forces. The results evaluation demonstrate that an infilled rocking wall frame can effectively avoid soft-story mechanisms. Capacity and initial stiffness are greatly improved and self-centering behavior is achieved with the help of the infilled rocking wall. Drift distribution becomes more uniform with height. Concrete cracks and damage occurs in desired areas. The infilled rocking wall frame offers a promising approach to achieving seismic resilience.

  17. On transforms between Gabor frames and wavelet frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2013-01-01

    We describe a procedure that enables us to construct dual pairs of wavelet frames from certain dual pairs of Gabor frames. Applying the construction to Gabor frames generated by appropriate exponential Bsplines gives wavelet frames generated by functions whose Fourier transforms are compactly...... supported splines with geometrically distributed knot sequences. There is also a reverse transform, which yields pairs of dual Gabor frames when applied to certain wavelet frames....

  18. A DSP-based neural network non-uniformity correction algorithm for IRFPA

    Science.gov (United States)

    Liu, Chong-liang; Jin, Wei-qi; Cao, Yang; Liu, Xiu

    2009-07-01

    An effective neural network non-uniformity correction (NUC) algorithm based on DSP is proposed in this paper. The non-uniform response in infrared focal plane array (IRFPA) detectors produces corrupted images with a fixed-pattern noise(FPN).We introduced and analyzed the artificial neural network scene-based non-uniformity correction (SBNUC) algorithm. A design of DSP-based NUC development platform for IRFPA is described. The DSP hardware platform designed is of low power consumption, with 32-bit fixed point DSP TMS320DM643 as the kernel processor. The dependability and expansibility of the software have been improved by DSP/BIOS real-time operating system and Reference Framework 5. In order to realize real-time performance, the calibration parameters update is set at a lower task priority then video input and output in DSP/BIOS. In this way, calibration parameters updating will not affect video streams. The work flow of the system and the strategy of real-time realization are introduced. Experiments on real infrared imaging sequences demonstrate that this algorithm requires only a few frames to obtain high quality corrections. It is computationally efficient and suitable for all kinds of non-uniformity.

  19. Heavy Ion Fusion Accelerator Research (HIFAR)

    International Nuclear Information System (INIS)

    1991-04-01

    This report discusses the following topics: emittance variations in current-amplifying ion induction lina; transverse emittance studies of an induction accelerator of heavy ions; drift compression experiments on MBE-4 and related emittance; low emittance uniform- density C s + sources for heavy ion fusion accelerator studies; survey of alignment of MBE-4; time-of-flight dependence on the MBE-4 quadrupole voltage; high order calculation of the multiple content of three dimensional electrostatic geometries; an induction linac injector for scaled experiments; induction accelerator test module for HIF; longitudinal instability in HIF beams; and analysis of resonant longitudinal instability in a heavy ion induction linac

  20. Implications of an absolute simultaneity theory for cosmology and universe acceleration.

    Science.gov (United States)

    Kipreos, Edward T

    2014-01-01

    An alternate Lorentz transformation, Absolute Lorentz Transformation (ALT), has similar kinematics to special relativity yet maintains absolute simultaneity in the context of a preferred reference frame. In this study, it is shown that ALT is compatible with current experiments to test Lorentz invariance only if the proposed preferred reference frame is locally equivalent to the Earth-centered non-rotating inertial reference frame, with the inference that in an ALT framework, preferred reference frames are associated with centers of gravitational mass. Applying this theoretical framework to cosmological data produces a scenario of universal time contraction in the past. In this scenario, past time contraction would be associated with increased levels of blueshifted light emissions from cosmological objects when viewed from our current perspective. The observation that distant Type Ia supernovae are dimmer than predicted by linear Hubble expansion currently provides the most direct evidence for an accelerating universe. Adjusting for the effects of time contraction on a redshift-distance modulus diagram produces a linear distribution of supernovae over the full redshift spectrum that is consistent with a non-accelerating universe.

  1. Implications of an absolute simultaneity theory for cosmology and universe acceleration.

    Directory of Open Access Journals (Sweden)

    Edward T Kipreos

    Full Text Available An alternate Lorentz transformation, Absolute Lorentz Transformation (ALT, has similar kinematics to special relativity yet maintains absolute simultaneity in the context of a preferred reference frame. In this study, it is shown that ALT is compatible with current experiments to test Lorentz invariance only if the proposed preferred reference frame is locally equivalent to the Earth-centered non-rotating inertial reference frame, with the inference that in an ALT framework, preferred reference frames are associated with centers of gravitational mass. Applying this theoretical framework to cosmological data produces a scenario of universal time contraction in the past. In this scenario, past time contraction would be associated with increased levels of blueshifted light emissions from cosmological objects when viewed from our current perspective. The observation that distant Type Ia supernovae are dimmer than predicted by linear Hubble expansion currently provides the most direct evidence for an accelerating universe. Adjusting for the effects of time contraction on a redshift-distance modulus diagram produces a linear distribution of supernovae over the full redshift spectrum that is consistent with a non-accelerating universe.

  2. Accelerator-driven neutron sources for materials research

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1990-01-01

    Particle accelerators are important tools for materials research and production. Advances in high-intensity linear accelerator technology make it possible to consider enhanced neutron sources for fusion material studies or as a source of spallation neutrons. Energy variability, uniformity of target dose distribution, target bombardment from multiple directions, time-scheduled dose patterns, and other features can be provided, opening new experimental opportunities. New designs have also been used to ensure hands-on maintenance on the accelerator in these factory-type facilities. Designs suitable for proposals such as the Japanese Energy-Selective Intense Neutron Source, and the international Fusion Materials Irradiation Facility are discussed

  3. A dual computed tomography linear accelerator unit for stereotactic radiation therapy: a new approach without cranially fixated stereotactic frames

    International Nuclear Information System (INIS)

    Uematsu, Minoru; Fukui, Toshiharu; Shioda, Akira; Tokumitsu, Hideyuki; Takai, Kenji; Kojima, Tadaharu; Asai, Yoshiko; Kusano, Shoichi

    1996-01-01

    Purpose: To perform stereotactic radiation therapy (SRT) without cranially fixated stereotactic frames, we developed a dual computed tomography (CT) linear accelerator (linac) treatment unit. Methods and Materials: This unit is composed of a linac, CT, and motorized table. The linac and CT are set up at opposite ends of the table, which is suitable for both machines. The gantry axis of the linac is coaxial with that of the CT scanner. Thus, the center of the target detected with the CT can be matched easily with the gantry axis of the linac by rotating the table. Positioning is confirmed with the CT for each treatment session. Positioning and treatment errors with this unit were examined by phantom studies. Between August and December 1994, 8 patients with 11 lesions of primary or metastatic brain tumors received SRT with this unit. All lesions were treated with 24 Gy in three fractions to 30 Gy in 10 fractions to the 80% isodose line, with or without conventional external beam radiation therapy. Results: Phantom studies revealed that treatment errors with this unit were within 1 mm after careful positioning. The position was easily maintained using two tiny metallic balls as vertical and horizontal marks. Motion of patients was negligible using a conventional heat-flexible head mold and dental impression. The overall time for a multiple noncoplanar arcs treatment for a single isocenter was less than 1 h on the initial treatment day and usually less than 20 min on subsequent days. Treatment was outpatient-based and well tolerated with no acute toxicities. Satisfactory responses have been documented. Conclusion: Using this treatment unit, multiple fractionated SRT is performed easily and precisely without cranially fixated stereotactic frames

  4. A unified approach to building accelerator simulation software for the SSC

    International Nuclear Information System (INIS)

    Paxson, V.; Aragon, C.; Peggs, S.; Saltmarsh, C.; Schachinger, L.

    1989-03-01

    To adequately simulate the physics and control of a complex accelerator requires a substantial number of programs which must present a uniform interface to both the user and the internal representation of the accelerator. If these programs are to be truly modular, so that their use can be orchestrated as needed, the specification of both their graphical and data interfaces must be carefully designed. We describe the state of such SSC simulation software, with emphasis on addressing these uniform interface needs by using a standardized data set format and object-oriented approaches to graphics and modeling. 12 refs

  5. Uniform electromagnetic field as viscous medium for moving particles

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Baltenkov, A.S.; Felfli, Z.; Msezane, A.Z.; Voitkiv, A.B.

    2002-01-01

    The mechanism of transverse radiation viscosity acting on free charges, atomic, and small macroscopic particles in uniform electromagnetic fields is analyzed. It is shown that in the process of light scattering by these particles, besides the force accelerating them in the direction of propagation of the radiation, there is a force in the transverse direction slowing them down. The general expression for this force is obtained. It is considered how this force can influence: (i) the motion of ultrarelativistic electrons in transverse photon fluxes; (ii) the behavior of a beam of nonrelativistic electrons moving in a copropagating uniform electromagnetic field; (iii) the transverse motion of atoms under the action of resonant radiation and (iv) the motion of small macroscopic particles

  6. Attribute Framing and Goal Framing Effects in Health Decisions.

    Science.gov (United States)

    Krishnamurthy, Parthasarathy; Carter, Patrick; Blair, Edward

    2001-07-01

    Levin, Schneider, and Gaeth (LSG, 1998) have distinguished among three types of framing-risky choice, attribute, and goal framing-to reconcile conflicting findings in the literature. In the research reported here, we focus on attribute and goal framing. LSG propose that positive frames should be more effective than negative frames in the context of attribute framing, and negative frames should be more effective than positive frames in the context of goal framing. We test this framework by manipulating frame valence (positive vs negative) and frame type (attribute vs goal) in a unified context with common procedures. We also argue that the nature of effects in a goal-framing context may depend on the extent to which the research topic has "intrinsic self-relevance" to the population. In the context of medical decision making, we operationalize low intrinsic self-relevance by using student subjects and high intrinsic self-relevance by using patients. As expected, we find complete support for the LSG framework under low intrinsic self-relevance and modified support for the LSG framework under high intrinsic self-relevance. Overall, our research appears to confirm and extend the LSG framework. Copyright 2001 Academic Press.

  7. Solid-state framing camera with multiple time frames

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K. L.; Stewart, R. E.; Steele, P. T.; Vernon, S. P.; Hsing, W. W.; Remington, B. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2013-10-07

    A high speed solid-state framing camera has been developed which can operate over a wide range of photon energies. This camera measures the two-dimensional spatial profile of the flux incident on a cadmium selenide semiconductor at multiple times. This multi-frame camera has been tested at 3.1 eV and 4.5 keV. The framing camera currently records two frames with a temporal separation between the frames of 5 ps but this separation can be varied between hundreds of femtoseconds up to nanoseconds and the number of frames can be increased by angularly multiplexing the probe beam onto the cadmium selenide semiconductor.

  8. Nonmonotonic belief state frames and reasoning frames

    NARCIS (Netherlands)

    Engelfriet, J.; Herre, H.; Treur, J.

    1995-01-01

    In this paper five levels of specification of nonmonotonic reasoning are distinguished. The notions of semantical frame, belief state frame and reasoning frame are introduced and used as a semantical basis for the first three levels. Moreover, the semantical connections between the levels are

  9. Improved seismic response of rc frame structures by using fluid viscous dampers

    International Nuclear Information System (INIS)

    Khan, Q.S.; Qazi, A.U.; Ilyas, M.

    2013-01-01

    In modern era passive control devices are used to improve the seismic response of structures during large magnitude earthquakes. In this research an analytical study is carried out on commercial FEM program SAP 2000 by modeling five, seven and nine storey RC frame structures. Response to four earthquake ground motions on modeled frame structures is studied and is effectively controlled by varying the characteristic properties of Fluid viscous dampers (FVD). Response in terms of frequency, displacement, velocity, acceleration, storey drift, base shear and energy dissipation is studied. Quantitatively in the modeled frames damage in terms of percentage change in global stiffness and natural frequency is determined. Qualitatively damage in terms of performance levels as per ATC-40 and FEMA-440 is considered. With an increase in Additional Stiffness Ratio of FVD corresponding increase in natural frequency and reduction in dynamic response is observed. FVDs significantly improve structural performance level of frames from Completely Damage to Immediate Occupancy/Operational Level during large magnitude earthquakes. (author)

  10. Ion acceleration in the plasma source sheath

    International Nuclear Information System (INIS)

    Birdsall, C.K.

    1986-01-01

    This note is a calculation of the potential drop for a planar plasma source, across the source sheath, into a uniform plasma region defined by vector E = 0 and/or perhaps ∂ 2 PHI/∂ x 2 = 0. The calculation complements that of Bohm who obtained the potential drop at the other end of a plasma, at a planar collector sheath. The result is a relation between the source ion flux and the source sheath potential drop and the accompanying ion acceleration. This planar source sheath ion acceleration mechanism (or that from a distributed source) can provide the pre-collector-sheath ion acceleration as found necessary by Bohm. 3 refs

  11. Non-Maximal Tripartite Entanglement Degradation of Dirac and Scalar Fields in Non-Inertial Frames

    International Nuclear Information System (INIS)

    Khan, Salman; Khan, Niaz Ali; Khan, M.K.

    2014-01-01

    The π-tangle is used to study the behavior of entanglement of a nonmaximal tripartite state of both Dirac and scalar fields in accelerated frame. For Dirac fields, the degree of degradation with acceleration of both one-tangle of accelerated observer and π-tangle, for the same initial entanglement, is different by just interchanging the values of probability amplitudes. A fraction of both one-tangles and the π-tangle always survives for any choice of acceleration and the degree of initial entanglement. For scalar field, the one-tangle of accelerated observer depends on the choice of values of probability amplitudes and it vanishes in the range of infinite acceleration, whereas for π-tangle this is not always true. The dependence of π-tangle on probability amplitudes varies with acceleration. In the lower range of acceleration, its behavior changes by switching between the values of probability amplitudes and for larger values of acceleration this dependence on probability amplitudes vanishes. Interestingly, unlike bipartite entanglement, the degradation of π-tangle against acceleration in the case of scalar fields is slower than for Dirac fields. (general)

  12. Role of drifts in diffusive shock acceleration

    International Nuclear Information System (INIS)

    Decker, R.B.

    1988-01-01

    The role played by shock-associated drifts during the diffusive acceleration of charged particles at collisionless MHD shocks is evaluated. In the rest frame of the shock, the total energy gained by a particle is shown to result from two coupled acceleration mechanisms, the usual first-order Fermi mechanism and the drift mechanism. When averaged over a distribution of particles, the ratio of the drift-associated energy gain to the total energy is found to be independent of the total energy at a given theta1 (the angle between the shock normal and the unperturbed upstream magnetic field) in agreement with theoretical predictions. No evidence is found for drift-associated deceleration, suggesting that drifts always augment acceleration. 35 references

  13. Low-frequency and wideband vibration energy harvester with flexible frame and interdigital structure

    Energy Technology Data Exchange (ETDEWEB)

    Li, Pengwei, E-mail: lipengwei@tyut.edu.cn; Wang, Yanfen; Luo, Cuixian; Li, Gang; Hu, Jie; Zhang, Wendong [MicroNano System Research Center of College of Information Engineering and Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Liu, Ying [MicroNano System Research Center of College of Information Engineering and Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Baicheng Ordnance Test Center of China, Baicheng 137000, Jilin (China); Liu, Wei [Baicheng Ordnance Test Center of China, Baicheng 137000, Jilin (China)

    2015-04-15

    As an alternative to traditional cantilever beam structures and their evolutions, a flexible beam based, interdigital structure, vibration energy harvester has been presented and investigated. The proposed interdigital-shaped oscillator consists of a rectangular flexible frame and series of cantilever beams interdigitally bonded to it. In order to achieve low frequency and wide-bandwidth harvesting, Young’s modulus of materials, frame size and the amount of the cantilevers have been studied systematically. The measured frequency responses of the designed device (PDMS frame, quintuple piezoelectric cantilever beams) show a 460% increase in bandwidth below 80Hz. When excited at an acceleration of 1.0 g, the energy harvester achieves to a maximum open-circuit voltage of 65V, and the maximum output power 4.5 mW.

  14. Skin carcinogenesis following uniform and non-uniform β irradiation

    International Nuclear Information System (INIS)

    Charles, M.W.; Williams, J.P.; Coggle, J.E.

    1989-01-01

    Where workers or the general public may be exposed to ionising radiation, the irradiation is rarely uniform. The risk figures and dose limits recommended by the International Commission on Radiological Protection (ICRP) are based largely on clinical and epidemiological studies of reasonably uniform irradiated organs. The paucity of clinical or experimental data for highly non-uniform exposures has prevented the ICRP from providing adequate recommendations. This weakness has led on a number of occasions to the postulate that highly non-uniform exposures of organs could be 100,000 times more carcinogenic than ICRP risk figures would predict. This so-called ''hot-particle hypothesis'' found little support among reputable radiobiologists, but could not be clearly and definitively refuted on the basis of experiment. An experiment, based on skin tumour induction in mouse skin, is described which was developed to test the hypothesis. The skin of 1200 SAS/4 male mice has been exposed to a range of uniform and non-uniform sources of the β emitter 170 Tm (E max ∼ 1 MeV). Non-uniform exposures were produced using arrays of 32 or 8 2-mm diameter sources distributed over the same 8-cm 2 area as a uniform control source. Average skin doses varied from 2-100 Gy. The results for the non-uniform sources show a 30% reduction in tumour incidence by the 32-point array at the lower mean doses compared with the response from uniform sources. The eight-point array showed an order-of-magnitude reduction in tumour incidence compared to uniform irradiation at low doses. These results, in direct contradiction to the ''hot particle hypothesis'', indicate that non-uniform exposures produce significantly fewer tumours than uniform exposures. (author)

  15. Hardware accelerator design for change detection in smart camera

    Science.gov (United States)

    Singh, Sanjay; Dunga, Srinivasa Murali; Saini, Ravi; Mandal, A. S.; Shekhar, Chandra; Chaudhury, Santanu; Vohra, Anil

    2011-10-01

    Smart Cameras are important components in Human Computer Interaction. In any remote surveillance scenario, smart cameras have to take intelligent decisions to select frames of significant changes to minimize communication and processing overhead. Among many of the algorithms for change detection, one based on clustering based scheme was proposed for smart camera systems. However, such an algorithm could achieve low frame rate far from real-time requirements on a general purpose processors (like PowerPC) available on FPGAs. This paper proposes the hardware accelerator capable of detecting real time changes in a scene, which uses clustering based change detection scheme. The system is designed and simulated using VHDL and implemented on Xilinx XUP Virtex-IIPro FPGA board. Resulted frame rate is 30 frames per second for QVGA resolution in gray scale.

  16. Advanced windows Information System (WIS): A uniform European tool to calculate the thermal and solar properties of windows

    NARCIS (Netherlands)

    Bakker, L.G.; Dijk, H.A.L. van

    1996-01-01

    WIS is a uniform, user friendly, PC-based, European software tool to determine the thermal and solar character-istics of window systems (glazing, frames, solar shading, etc.) and window components. WIS includes databases with component properties and routines for calculation of the thermal-optical

  17. Group-Theoretical Revision of the Unruh Effect

    International Nuclear Information System (INIS)

    Calixto, M; Perez-Romero, E; Aldaya, V

    2011-01-01

    We revise the Unruh effect (vacuum radiation in uniformly relativistic accelerated frames) in a group-theoretical setting by constructing a conformal SO(4,2)-invariant quantum field theory and its spontaneous breakdown when selecting Poincare invariant degenerated vacua (namely, coherent states of conformal zero modes). Special conformal transformations (accelerations) destabilize the Poincare vacuum and make it to radiate.

  18. Group-Theoretical Revision of the Unruh Effect

    Energy Technology Data Exchange (ETDEWEB)

    Calixto, M [Departamento de Matematica Aplicada y Estadistica, Universidad Politecnica de Cartagena, Paseo Alfonso XIII 56, 30203 Cartagena (Spain); Perez-Romero, E; Aldaya, V, E-mail: Manuel.Calixto@upct.es [Instituto de Astrofisica de Andalucia (IAA-CSIC), Apartado Postal 3004, 18080 Granada (Spain)

    2011-03-01

    We revise the Unruh effect (vacuum radiation in uniformly relativistic accelerated frames) in a group-theoretical setting by constructing a conformal SO(4,2)-invariant quantum field theory and its spontaneous breakdown when selecting Poincare invariant degenerated vacua (namely, coherent states of conformal zero modes). Special conformal transformations (accelerations) destabilize the Poincare vacuum and make it to radiate.

  19. Experimental study of laser acceleration of planar targets at the wavelength 0.26 μm

    International Nuclear Information System (INIS)

    Fabbro, R.; Faral, B.; Cottet, F.; Romain, J.P.

    1984-01-01

    The main characteristics of accelerated aluminum targets, which are the target velocity, the uniformity of the acceleration and the backside temperature have been studied in laser experiments performed at wavelength 0.26 μm with an absorbed flux of a few 10 13 W/cm 2 , in 400-ps pulse duration by using the double-foil technique and an optical pyrometry diagnostic: The ablation pressure was inferred from the velocity measurements. The uniformity of the acceleration was shown to be controlled by the hot spots in the focal spot, and the importance of studying the smoothing of laser inhomogeneities for accelerated targets with large ablated fractions was emphasized. The observed dependence of the backside temperature as a function of the initial foil thickness is discussed in the light of shock wave heating and radiative heating

  20. The Convergence Acceleration of Two-Dimensional Fourier Interpolation

    Directory of Open Access Journals (Sweden)

    Anry Nersessian

    2008-07-01

    Full Text Available Hereby, the convergence acceleration of two-dimensional trigonometric interpolation for a smooth functions on a uniform mesh is considered. Together with theoretical estimates some numerical results are presented and discussed that reveal the potential of this method for application in image processing. Experiments show that suggested algorithm allows acceleration of conventional Fourier interpolation even for sparse meshes that can lead to an efficient image compression/decompression algorithms and also to applications in image zooming procedures.

  1. Improved frame-based estimation of head motion in PET brain imaging

    International Nuclear Information System (INIS)

    Mukherjee, J. M.; Lindsay, C.; King, M. A.; Licho, R.; Mukherjee, A.; Olivier, P.; Shao, L.

    2016-01-01

    Purpose: Head motion during PET brain imaging can cause significant degradation of image quality. Several authors have proposed ways to compensate for PET brain motion to restore image quality and improve quantitation. Head restraints can reduce movement but are unreliable; thus the need for alternative strategies such as data-driven motion estimation or external motion tracking. Herein, the authors present a data-driven motion estimation method using a preprocessing technique that allows the usage of very short duration frames, thus reducing the intraframe motion problem commonly observed in the multiple frame acquisition method. Methods: The list mode data for PET acquisition is uniformly divided into 5-s frames and images are reconstructed without attenuation correction. Interframe motion is estimated using a 3D multiresolution registration algorithm and subsequently compensated for. For this study, the authors used 8 PET brain studies that used F-18 FDG as the tracer and contained minor or no initial motion. After reconstruction and prior to motion estimation, known motion was introduced to each frame to simulate head motion during a PET acquisition. To investigate the trade-off in motion estimation and compensation with respect to frames of different length, the authors summed 5-s frames accordingly to produce 10 and 60 s frames. Summed images generated from the motion-compensated reconstructed frames were then compared to the original PET image reconstruction without motion compensation. Results: The authors found that our method is able to compensate for both gradual and step-like motions using frame times as short as 5 s with a spatial accuracy of 0.2 mm on average. Complex volunteer motion involving all six degrees of freedom was estimated with lower accuracy (0.3 mm on average) than the other types investigated. Preprocessing of 5-s images was necessary for successful image registration. Since their method utilizes nonattenuation corrected frames, it is

  2. Improved frame-based estimation of head motion in PET brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, J. M., E-mail: joyeeta.mitra@umassmed.edu; Lindsay, C.; King, M. A.; Licho, R. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Mukherjee, A. [Aware, Inc., Bedford, Massachusetts 01730 (United States); Olivier, P. [Philips Medical Systems, Cleveland, Ohio 44143 (United States); Shao, L. [ViewRay, Oakwood Village, Ohio 44146 (United States)

    2016-05-15

    Purpose: Head motion during PET brain imaging can cause significant degradation of image quality. Several authors have proposed ways to compensate for PET brain motion to restore image quality and improve quantitation. Head restraints can reduce movement but are unreliable; thus the need for alternative strategies such as data-driven motion estimation or external motion tracking. Herein, the authors present a data-driven motion estimation method using a preprocessing technique that allows the usage of very short duration frames, thus reducing the intraframe motion problem commonly observed in the multiple frame acquisition method. Methods: The list mode data for PET acquisition is uniformly divided into 5-s frames and images are reconstructed without attenuation correction. Interframe motion is estimated using a 3D multiresolution registration algorithm and subsequently compensated for. For this study, the authors used 8 PET brain studies that used F-18 FDG as the tracer and contained minor or no initial motion. After reconstruction and prior to motion estimation, known motion was introduced to each frame to simulate head motion during a PET acquisition. To investigate the trade-off in motion estimation and compensation with respect to frames of different length, the authors summed 5-s frames accordingly to produce 10 and 60 s frames. Summed images generated from the motion-compensated reconstructed frames were then compared to the original PET image reconstruction without motion compensation. Results: The authors found that our method is able to compensate for both gradual and step-like motions using frame times as short as 5 s with a spatial accuracy of 0.2 mm on average. Complex volunteer motion involving all six degrees of freedom was estimated with lower accuracy (0.3 mm on average) than the other types investigated. Preprocessing of 5-s images was necessary for successful image registration. Since their method utilizes nonattenuation corrected frames, it is

  3. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  4. Uniform current density and divergence control in high power extraction ion diodes

    International Nuclear Information System (INIS)

    Desjarlais, M.P.; Coats, R.S.; Lockner, T.R.; Pointon, T.D.; Johnson, D.J.; Slutz, S.A.; Lemke, R.W.; Cuneo, M.E.; Mehlhorn, T.A.

    1996-01-01

    A theory of radial beam uniformity in extraction ion diodes is presented. The theory is based on a locally one-dimensional analysis of the diamagnetic compression of magnetic streamlines and the self-consistent determination of the virtual cathode location. The radial dependence of the applied magnetic field is used to determine the critical parameters of this locally one-dimensional treatment. The theory has been incorporated into the ATHETA magnetic field code to allow the rapid evaluation of realistic magnetic field configurations. Comparisons between the theoretical results, simulations with the QUICKSILVER code, and experiments on the PBFA-X accelerator establish the usefulness of this tool for tuning magnetic fields to improve ion beam uniformity. The consequences of poor beam uniformity on the evolution of ion diode instabilities are discussed with supporting evidence from simulations, theory, and experiments. (author). 8 figs., 15 refs

  5. Uniform current density and divergence control in high power extraction ion diodes

    International Nuclear Information System (INIS)

    Desjarlais, M.P.; Coats, R.S.; Lockner, T.R.; Pointon, T.D.; Johnson, D.J.; Slutz, S.A.; Lemke, R.W.; Cuneo, M.E.; Melhorn, T.A.

    1996-01-01

    A theory of radial beam uniformity in extraction ion diodes is presented. The theory is based on a locally one dimensional analysis of the diamagnetic compression of magnetic streamlines and the self consistent determination of the virtual cathode location. The radial dependence of the applied magnetic field is used to determine the critical parameters of this locally one dimensional treatment. The theory has been incorporated into the ATHETA magnetic field code to allow the rapid evaluation of realistic magnetic field configurations. Comparisons between the theoretical results, simulations with the QUICKSILVER code, and experiments on the PBFA-X accelerator establish the usefulness of this tool for tuning magnetic fields to improve ion beam uniformity. The consequences of poor beam uniformity on the evolution of ion diode instabilities are discussed with supporting evidence from simulations, theory, and experiments

  6. Uniform current density and divergence control in high power extraction ion diodes

    Energy Technology Data Exchange (ETDEWEB)

    Desjarlais, M P; Coats, R S; Lockner, T R; Pointon, T D; Johnson, D J; Slutz, S A; Lemke, R W; Cuneo, M E; Mehlhorn, T A [Sandia Labs., Albuquerque, NM (United States)

    1997-12-31

    A theory of radial beam uniformity in extraction ion diodes is presented. The theory is based on a locally one-dimensional analysis of the diamagnetic compression of magnetic streamlines and the self-consistent determination of the virtual cathode location. The radial dependence of the applied magnetic field is used to determine the critical parameters of this locally one-dimensional treatment. The theory has been incorporated into the ATHETA magnetic field code to allow the rapid evaluation of realistic magnetic field configurations. Comparisons between the theoretical results, simulations with the QUICKSILVER code, and experiments on the PBFA-X accelerator establish the usefulness of this tool for tuning magnetic fields to improve ion beam uniformity. The consequences of poor beam uniformity on the evolution of ion diode instabilities are discussed with supporting evidence from simulations, theory, and experiments. (author). 8 figs., 15 refs.

  7. Media Framing

    DEFF Research Database (Denmark)

    Pedersen, Rasmus T.

    2017-01-01

    The concept of media framing refers to the way in which the news media organize and provide meaning to a news story by emphasizing some parts of reality and disregarding other parts. These patterns of emphasis and exclusion in news coverage create frames that can have considerable effects on news...... consumers’ perceptions and attitudes regarding the given issue or event. This entry briefly elaborates on the concept of media framing, presents key types of media frames, and introduces the research on media framing effects....

  8. Acceleration radiation in a compact space

    International Nuclear Information System (INIS)

    Copeland, E.J.; Davies, P.C.W.; Hinton, K.

    1984-01-01

    The response is studied of a uniformly accelerated model particle detector in a spacetime with compact spatial sections. The basic thermal character of the response re-emerges, in spite of the fact that the spacetime does not possess event horizons. The model also permits a study of detector response to twisted field states. (author)

  9. Analytic theory of the Rayleigh-Taylor instability in a uniform density plasma-filled ion diode

    International Nuclear Information System (INIS)

    Hussey, T.W.; Payne, S.S.

    1987-04-01

    The J-vector x B-vector forces associated with the surface current of a plasma-filled ion diode will accelerate this plasma fill toward the anode surface. It is well known that such a configuration with a high I is susceptible to the hydromagnetic Rayleigh-Taylor instability in certain geometries. A number of ion diode plasma sources have been proposed, most of which have a falling density going away from the wall. A somewhat more unstable case, however, is that of uniform density. In this report we attempt to establish an upper limit on this effect with a simple analytic model in which a uniform-density plasma is accelerated by the magnetic field anticipated in a PBFA-II diode. We estimate the number of linear e-foldings experienced by an unstable surface as well as the most damaging wavelength initial perturbation. This model, which accounts approximately for stabilization due to field diffusion, suggests that even with a uniform fill, densities in excess of a few 10 15 are probably not damaged by the instability. In addition, even lower densities might be tolerated if perturbations near the most damaging wavelength can be kept very small

  10. Framing effects over time: comparing affective and cognitive news frames

    NARCIS (Netherlands)

    Lecheler, S.; Matthes, J.

    2012-01-01

    A growing number of scholars examine the duration of framing effects. However, duration is likely to differ from frame to frame, depending on how strong a frame is. This strength is likely to be enhanced by adding emotional components to a frame. By means of an experimental survey design (n = 111),

  11. An Expert System For Tuning Particle-Beam Accelerators

    Science.gov (United States)

    Lager, Darrel L.; Brand, Hal R.; Maurer, William J.; Searfus, Robert M.; Hernandez, Jose E.

    1989-03-01

    We have developed a proof-of-concept prototype of an expert system for tuning particle beam accelerators. It is designed to function as an intelligent assistant for an operator. In its present form it implements the strategies and reasoning followed by the operator for steering through the beam transport section of the Advanced Test Accelerator at Lawrence Livermore Laboratory's Site 300. The system is implemented in the language LISP using the Artificial Intelligence concepts of frames, daemons, and a representation we developed called a Monitored Decision Script.

  12. Speeding Up Simulations of Relativistic Systems using an Optimal Boosted Frame

    International Nuclear Information System (INIS)

    Vay, J.-L.; Fawley, W.M.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2009-01-01

    It can be computationally advantageous to perform computer simulations in a Lorentz boosted frame for a certain class of systems. However, even if the computer model relies on a covariant set of equations, it has been pointed out that algorithmic difficulties related to discretization errors may have to be overcome in order to take full advantage of the potential speedup. We summarize the findings, the difficulties and their solutions, and show that the technique enables simulations important to several areas of accelerator physics that are otherwise problematic, including self-consistent modeling in three-dimensions of laser wokefield accelerator stages at energies of 10 GeV and above.

  13. Radiometric determination of uniformity of putting paraffin on textile threads

    International Nuclear Information System (INIS)

    Ridel', Z.; Kherrmann, Eh.; Shefer, I.; Tseiner, A.

    1979-01-01

    To improve processing of the natural and synthetic fiber threads on stocking-frames, they are treated by paraffin. Paraffin is applied in the amounts nearly equal to 0.1 -1.0 g for 10 4 m of the thread's length. To determine amount of paraffin on thread and to determine uniformity if its application, a radiometric method has been developed. As a radioactive label, didocilephosphate of rare earths was used. This compound has good solubility in hydrocarbons and does not change physical properties of paraffin in the investigated field of its application as well as its concentration. It is possible to add to paraffin this radioactive label or a non-active label with subsequent its activation. Amount of paraffin, applied on a thread is determined by means of measurement of activity of thread samples of different length. Information about uniformity of paraffin application on thread have been obtained by means of autoradiography. It has been found that paraffin in mainly applied on the thread's bulges [ru

  14. Low-frequency and wideband vibration energy harvester with flexible frame and interdigital structure

    Directory of Open Access Journals (Sweden)

    Pengwei Li

    2015-04-01

    Full Text Available As an alternative to traditional cantilever beam structures and their evolutions, a flexible beam based, interdigital structure, vibration energy harvester has been presented and investigated. The proposed interdigital-shaped oscillator consists of a rectangular flexible frame and series of cantilever beams interdigitally bonded to it. In order to achieve low frequency and wide-bandwidth harvesting, Young’s modulus of materials, frame size and the amount of the cantilevers have been studied systematically. The measured frequency responses of the designed device (PDMS frame, quintuple piezoelectric cantilever beams show a 460% increase in bandwidth below 80Hz. When excited at an acceleration of 1.0 g, the energy harvester achieves to a maximum open-circuit voltage of 65V, and the maximum output power 4.5 mW.

  15. Comment on ''Vacuum stress-energy tensor of the electromagnetic field in rotating frames''

    International Nuclear Information System (INIS)

    Mane, S.R.

    1991-01-01

    Hacyan and Sarmiento have found that an observer accelerating in a circle will detect a nonzero energy flux (Poynting vector) caused by the vacuum electromagnetic fluctuations in that frame. I wish to suggest that the above flux is related to synchrotron radiation. I treat only the leading order of perturbation theory

  16. Characteristics of diffusion flames with accelerated motion

    Directory of Open Access Journals (Sweden)

    Lou Bo

    2016-01-01

    Full Text Available The aim of this work is to present an experiment to study the characteristics of a laminar diffusion flame under acceleration. A Bunsen burner (nozzle diameter 8 mm, using liquefied petroleum gas as its fuel, was ignited under acceleration. The temperature field and the diffusion flame angle of inclination were visualised with the assistance of the visual display technology incorporated in MATLAB™. Results show that the 2-d temperature field under different accelerations matched the variation in average temperatures: they both experience three variations at different time and velocity stages. The greater acceleration has a faster change in average temperature with time, due to the accumulation of combustion heat: the smaller acceleration has a higher average temperature at the same speed. No matter what acceleration was used, in time, the flame angle of inclination increased, but the growth rate decreased until an angle of 90°: this could be explained by analysis of the force distribution within the flame. It is also found that, initially, the growth rate of angle with velocity under the greater acceleration was always smaller than that at lower accelerations; it was also different in flames with uniform velocity fire conditions.

  17. Riesz frames and approximation of the frame coefficients

    DEFF Research Database (Denmark)

    Casazza, P.; Christensen, Ole

    1998-01-01

    A frame is a fmaily {f i } i=1 ∞ of elements in a Hilbert space with the property that every element in can be written as a (infinite) linear combination of the frame elements. Frame theory describes how one can choose the corresponding coefficients, which are called frame coefficients. From...... the mathematical point of view this is gratifying, but for applications it is a problem that the calculation requires inversion of an operator on . The projection method is introduced in order to avoid this problem. The basic idea is to consider finite subfamilies {f i } i=1 n of the frame and the orthogonal...... projection Pn onto its span. For has a representation as a linear combination of fi, i=1,2,..., n and the corresponding coefficients can be calculated using finite dimensional methods. We find conditions implying that those coefficients converge to the correct frame coefficients as n→∞, in which case we have...

  18. Frames of exponentials:lower frame bounds for finite subfamilies, and approximation of the inverse frame operator

    DEFF Research Database (Denmark)

    Christensen, Ole; Lindner, Alexander M

    2001-01-01

    We give lower frame bounds for finite subfamilies of a frame of exponentials {e(i lambdak(.))}k is an element ofZ in L-2(-pi,pi). We also present a method for approximation of the inverse frame operator corresponding to {e(i lambdak(.))}k is an element ofZ, where knowledge of the frame bounds for...

  19. Body fixed frame, rigid gauge rotations and large N random fields in QCD

    International Nuclear Information System (INIS)

    Levit, S.

    1995-01-01

    The ''body fixed frame'' with respect to local gauge transformations is introduced. Rigid gauge ''rotations'' in QCD and their Schroedinger equation are studied for static and dynamic quarks. Possible choices of the rigid gauge field configuration corresponding to a non-vanishing static colormagnetic field in the ''body fixed'' frame are discussed. A gauge invariant variational equation is derived in this frame. For large number N of colors the rigid gauge field configuration is regarded as random with maximally random probability distribution under constraints on macroscopic-like quantities. For the uniform magnetic field the joint probability distribution of the field components is determined by maximizing the appropriate entropy under the area law constraint for the Wilson loop. In the quark sector the gauge invariance requires the rigid gauge field configuration to appear not only as a background but also as inducing an instantaneous quark-quark interaction. Both are random in the large N limit. (orig.)

  20. Experimental study of laser acceleration of planar targets at the wavelength 0. 26. mu. m

    Energy Technology Data Exchange (ETDEWEB)

    Fabbro, R.; Faral, B.; Cottet, F.; Romain, J.P.

    1984-12-01

    The main characteristics of accelerated aluminum targets, which are the target velocity, the uniformity of the acceleration and the backside temperature have been studied in laser experiments performed at wavelength 0.26 ..mu..m with an absorbed flux of a few 10/sup 13/ W/cm/sup 2/, in 400-ps pulse duration by using the double-foil technique and an optical pyrometry diagnostic: The ablation pressure was inferred from the velocity measurements. The uniformity of the acceleration was shown to be controlled by the hot spots in the focal spot, and the importance of studying the smoothing of laser inhomogeneities for accelerated targets with large ablated fractions was emphasized. The observed dependence of the backside temperature as a function of the initial foil thickness is discussed in the light of shock wave heating and radiative heating.

  1. Acceleration of a two-phase flow by boiling, (3)

    International Nuclear Information System (INIS)

    Mori, Yasuo; Hijikata, Kunio; Iwata, Shoichiro

    1976-01-01

    Acceleration of two-component, two-phase flow has been studied, and a method using the volume expansion by boiling for accelerating fluid has been investigated. In this study, the phenomena of atomizing and boiling were separated, and the liquid with low boiling point was injected into water at lower than the saturation temperature, and was atomized. Then, this was mixed with high temperature liquid and was boiled. The uniform buffle flow was produced, and the phenomena were observed with a high speed camera. The process of acceleration and the acceleration performance were compared with the results of theoretical analysis described in the second report. The experiment was carried out with liquid R113, and at first, the mechanism of atomizing was studied. The atomizing was caused when the relative velocity between R113 and water was more than 4 m/s irrespective of water velocity. The distribution of the diameter of fine liquid drops was almost normal distribution. When the fine drops of R113 were mixed with the high temperature water, bubbles were produced, and the production rate showed definite dependence on the degree of overheating. The flow of bubbles was uniform. However, some of R113 did not become bubbles. The efficiency of acceleration was 1.0 which was independent of the degree of overheating. A further problem is to reduce the quantity of the liquid which does not boil. (Kato, T.)

  2. Prime tight frames

    DEFF Research Database (Denmark)

    Lemvig, Jakob; Miller, Christopher; Okoudjou, Kasso A.

    2014-01-01

    to suggest effective analysis and synthesis computation strategies for such frames. Finally, we describe all prime frames constructed from the spectral tetris method, and, as a byproduct, we obtain a characterization of when the spectral tetris construction works for redundancies below two.......We introduce a class of finite tight frames called prime tight frames and prove some of their elementary properties. In particular, we show that any finite tight frame can be written as a union of prime tight frames. We then characterize all prime harmonic tight frames and use thischaracterization...

  3. Accelerator mass spectrometry in NIPNE

    International Nuclear Information System (INIS)

    Ivascu, M; Marinescu, L.; Dima, R.; Cata-Danil, D.; Petrascu, M.; Popescu, I.; Stan-Sion, C.; Radulescu, M.; Plostinaru, D.

    1997-01-01

    The Accelerator Mass Spectrometry (AMS) is today the method capable to measure the lowest concentration of a particular nuclide in sample materials. The method has applications in environmental physics, medicine, measurements of cosmic-ray or nuclear power plant produced radionuclides in the earth's atmosphere. All over the world, more than 40 charged particles and heavy ion accelerators are performing such analyses concerning the research interest of a huge number of laboratories. The Romanian Institute of Nuclear Physics and Engineering in Bucharest has initiated a construction project for the AMS facility at the FN - Van de Graaff Tandem accelerator. This program benefits of technical and financial assistance provided by IAEA in the frame of the IAEA-TC Project ROM 8014-265C. A general lay-out of the AMS project is presented. The construction work has begun and first tests of the AMS injector will take place between July - September this year. (authors)

  4. Characterization of a 512x512-pixel 8-output full-frame CCD for high-speed imaging

    Science.gov (United States)

    Graeve, Thorsten; Dereniak, Eustace L.

    1993-01-01

    The characterization of a 512 by 512 pixel, eight-output full frame CCD manufactured by English Electric Valve under part number CCD13 is discussed. This device is a high- resolution Silicon-based array designed for visible imaging applications at readout periods as low as two milliseconds. The characterization of the device includes mean-variance analysis to determine read noise and dynamic range, as well as charge transfer efficiency, MTF, and quantum efficiency measurements. Dark current and non-uniformity issues on a pixel-to-pixel basis and between individual outputs are also examined. The characterization of the device is restricted by hardware limitations to a one MHz pixel rate, corresponding to a 40 ms readout time. However, subsections of the device have been operated at up to an equivalent 100 frames per second. To maximize the frame rate, the CCD is illuminated by a synchronized strobe flash in between frame readouts. The effects of the strobe illumination on the imagery obtained from the device is discussed.

  5. Quantum frames

    Science.gov (United States)

    Brown, Matthew J.

    2014-02-01

    The framework of quantum frames can help unravel some of the interpretive difficulties i the foundation of quantum mechanics. In this paper, I begin by tracing the origins of this concept in Bohr's discussion of quantum theory and his theory of complementarity. Engaging with various interpreters and followers of Bohr, I argue that the correct account of quantum frames must be extended beyond literal space-time reference frames to frames defined by relations between a quantum system and the exosystem or external physical frame, of which measurement contexts are a particularly important example. This approach provides superior solutions to key EPR-type measurement and locality paradoxes.

  6. Frame scaling function sets and frame wavelet sets in Rd

    International Nuclear Information System (INIS)

    Liu Zhanwei; Hu Guoen; Wu Guochang

    2009-01-01

    In this paper, we classify frame wavelet sets and frame scaling function sets in higher dimensions. Firstly, we obtain a necessary condition for a set to be the frame wavelet sets. Then, we present a necessary and sufficient condition for a set to be a frame scaling function set. We give a property of frame scaling function sets, too. Some corresponding examples are given to prove our theory in each section.

  7. Seismic Performance of a Corroded Reinforce Concrete Frame Structure Using Pushover Method

    Directory of Open Access Journals (Sweden)

    Meng Zhang

    2018-01-01

    Full Text Available SAP2000 software was used to build the finite element model of a six-storey-three-span reinforced concrete (RC frame structure. The numerical simulation of the seismic performance of the RC frame structure incorporating different levels of rebar corrosion was conducted using pushover analysis method. The degradation characteristics of the seismic performance of the corroded structure under severe earthquake were also analyzed. The results show that the seismic performance of the RC frame decreased significantly due to corrosion of the longitudinal rebars. And the interstory drift ratios increase dramatically with the increasing of the corrosion rate. At the same time, the formation and development of plastic hinges (beam hinges or column hinges will accelerate, which leads to a more aggravated deformation of the structure under rare earthquake action, resulting in a negative effect to the seismic bearing capacity of the structure.

  8. State registration and inspection programs for particle accelerators

    International Nuclear Information System (INIS)

    Bailey, E.D.

    1976-01-01

    The Suggested State Regulations for Control of Radiation(SSRCR) are recommended by the Council of State Governments and the National Conference of Radiation Control Program Directors as the model regulations which states should adopt in order to have adequate regulation and uniformity from state to state. These regulations are used as a basis for reviewing the current status of accelerator regulation in each state. The SSRCR does contain a separate part for registration (Part B--Registration of Radiation Machine Facilities and Services) and a separate part (Part I--Radiation Safety Requirements for Particle Accelerators) with specific requirements for the possession and use of accelerators. In addition, medical accelerators have additional requirements in Part F--X-Rays in The Heating Acts. These regulations specify requirements related to limitations of use, shielding and safety design requirements, control and interlock systems, warning devices, operating procedures, radiation monitoring, and calibration of medical accelerators

  9. Riesz Frames and Approximation of the Frame Coefficients

    DEFF Research Database (Denmark)

    Christensen, Ole

    1996-01-01

    A frame is a familyof elements in a Hilbert space with the propertythat every element in the Hilbert space can be written as a (infinite)linear combination of the frame elements. Frame theory describes howone can choose the corresponding coefficients, which are calledframe coefficients. From...... the mathematical point of view this isgratifying, but for applications it is a problem that the calculationrequires inversion of an operator on the Hilbert space.The projection method is introduced in order to avoid this problem.The basic idea is to consider finite subfamiliesof the frame and the orthogonal...... projection onto its span. Forfin QTR H,P_nf has a representation as a linear combinationof f_i,i=1,2,..,n, and the corresponding coefficients can be calculatedusing finite dimensional methods. We find conditions implying that thosecoefficients converge to the correct frame coefficients as n goes...

  10. Accelerators in industrial electron beam processing

    International Nuclear Information System (INIS)

    Becker, R.C.

    1984-01-01

    High power electron beam accelerators are being used for a variety of industrial processes. Such machines can process a wide range of products at very high thruput rates and at very low unit processing costs. These industrial accelerators are now capable of producing up to 200 kW of electron beam power at 4.0 MV and 100 kW at 5.0 MV. At this writing, even larger units are contemplated. The reliability of these high power devices also makes it feasible to consider bremsstrahlung (x-ray) processing as well. In addition to the advance of accelerator technology, microprocessor control systems now provide the capability to coordinate all the operations of the irradiation facility, including the accelerator, the material handling system, the personnel safety system and various auxiliary services. Facility designs can be adapted to many different industrial processes, including use of the dual purpose electron/x-ray accelerator, to ensure satisfactory product treatment with good dose uniformity, high energy efficiency and operational safety and simplicity. In addition, equipment manufacturers like RDI are looking beyond their conventional DC accelerator technology; looking at high power 10-12 MeV linear accelerators with power levels up to 25 kW or more. These high power linear accelerators could be the ideal processing tool for many sterilization and food irradiation applications. (author)

  11. Improving uniformity of atmospheric-pressure dielectric barrier discharges using dual frequency excitation

    Science.gov (United States)

    Liu, Y.; Peeters, F. J. J.; Starostin, S. A.; van de Sanden, M. C. M.; de Vries, H. W.

    2018-01-01

    This letter reports a novel approach to improve the uniformity of atmospheric-pressure dielectric barrier discharges using a dual-frequency excitation consisting of a low frequency (LF) at 200 kHz and a radio frequency (RF) at 13.56 MHz. It is shown that due to the periodic oscillation of the RF electric field, the electron acceleration and thus the gas ionization is temporally modulated, i.e. enhanced and suppressed during each RF cycle. As a result, the discharge development is slowed down with a lower amplitude and a longer duration of the LF discharge current. Hence, the RF electric field facilitates improved stability and uniformity simultaneously allowing a higher input power.

  12. A systematic FPGA acceleration design for applications based on convolutional neural networks

    Science.gov (United States)

    Dong, Hao; Jiang, Li; Li, Tianjian; Liang, Xiaoyao

    2018-04-01

    Most FPGA accelerators for convolutional neural network are designed to optimize the inner acceleration and are ignored of the optimization for the data path between the inner accelerator and the outer system. This could lead to poor performance in applications like real time video object detection. We propose a brand new systematic FPFA acceleration design to solve this problem. This design takes the data path optimization between the inner accelerator and the outer system into consideration and optimizes the data path using techniques like hardware format transformation, frame compression. It also takes fixed-point, new pipeline technique to optimize the inner accelerator. All these make the final system's performance very good, reaching about 10 times the performance comparing with the original system.

  13. Radiative processes for Rindler and accelerating observers and the stress-tensor detector

    International Nuclear Information System (INIS)

    Paola, R. De; Svaiter, N.F.

    1996-04-01

    It is considered a monopole detector interacting with a massive scalar field. Using the rotating wave approximation the radiative processes is discussed from the accelerated frame point of view. After this, it is obtained the Minkowski vacuum stress tensor measured by the accelerated observer using a non-gravitational stress sensor detector. Finally we analyse radiative processes of the monopole detector travelling in a world line that is inertial in the infinite past and has a constant proper acceleration in the infinite future. (author). 30 refs

  14. Frames and counter-frames giving meaning to dementia: a framing analysis of media content.

    Science.gov (United States)

    Van Gorp, Baldwin; Vercruysse, Tom

    2012-04-01

    Media tend to reinforce the stigmatization of dementia as one of the most dreaded diseases in western society, which may have repercussions on the quality of life of those with the illness. The persons with dementia, but also those around them become imbued with the idea that life comes to an end as soon as the diagnosis is pronounced. The aim of this paper is to understand the dominant images related to dementia by means of an inductive framing analysis. The sample is composed of newspaper articles from six Belgian newspapers (2008-2010) and a convenience sample of popular images of the condition in movies, documentaries, literature and health care communications. The results demonstrate that the most dominant frame postulates that a human being is composed of two distinct parts: a material body and an immaterial mind. If this frame is used, the person with dementia ends up with no identity, which is in opposition to the Western ideals of personal self-fulfilment and individualism. For each dominant frame an alternative counter-frame is defined. It is concluded that the relative absence of counter-frames confirms the negative image of dementia. The inventory might be a help for caregivers and other professionals who want to evaluate their communication strategy. It is discussed that a more resolute use of counter-frames in communication about dementia might mitigate the stigma that surrounds dementia. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Relativistic quantum games in noninertial frames

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Salman; Khan, M Khalid, E-mail: sksafi@phys.qau.edu.pk [Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2011-09-02

    We study the influence of the Unruh effect on quantum non-zero sum games. In particular, we investigate the quantum Prisoners' Dilemma both for entangled and unentangled initial states and show that the acceleration of the noninertial frames disturbs the symmetry of the game. It is shown that for the maximally entangled initial state, the classical strategy C-hat (cooperation) becomes the dominant strategy. Our investigation shows that any quantum strategy does no better for any player against the classical strategies. The miracle move of Eisert et al (1999 Phys. Rev. Lett.83 3077) is no more a superior move. We show that the dilemma-like situation is resolved in favor of one player or the other. (paper)

  16. Relativistic quantum games in noninertial frames

    International Nuclear Information System (INIS)

    Khan, Salman; Khan, M Khalid

    2011-01-01

    We study the influence of the Unruh effect on quantum non-zero sum games. In particular, we investigate the quantum Prisoners' Dilemma both for entangled and unentangled initial states and show that the acceleration of the noninertial frames disturbs the symmetry of the game. It is shown that for the maximally entangled initial state, the classical strategy C-hat (cooperation) becomes the dominant strategy. Our investigation shows that any quantum strategy does no better for any player against the classical strategies. The miracle move of Eisert et al (1999 Phys. Rev. Lett.83 3077) is no more a superior move. We show that the dilemma-like situation is resolved in favor of one player or the other. (paper)

  17. Assessment indices for uniform and non-uniform thermal environments

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Different assessment indices for thermal environments were compared and selected for proper assessment of indoor thermal environments.30 subjects reported their overall thermal sensation,thermal comfort,and thermal acceptability in uniform and non-uniform conditions.The results show that these three assessment indices provide equivalent evaluations in uniform environments.However,overall thermal sensation differs from the other two indices and cannot be used as a proper index for the evaluation of non-uniform environments.The relationship between the percentage and the mean vote for each index is established.

  18. Body frames and frame singularities for three-atom systems

    International Nuclear Information System (INIS)

    Littlejohn, R.G.; Mitchell, K.A.; Aquilanti, V.; Cavalli, S.

    1998-01-01

    The subject of body frames and their singularities for three-particle systems is important not only for large-amplitude rovibrational coupling in molecular spectroscopy, but also for reactive scattering calculations. This paper presents a geometrical analysis of the meaning of body frame conventions and their singularities in three-particle systems. Special attention is devoted to the principal axis frame, a certain version of the Eckart frame, and the topological inevitability of frame singularities. The emphasis is on a geometrical picture, which is intended as a preliminary study for the more difficult case of four-particle systems, where one must work in higher-dimensional spaces. The analysis makes extensive use of kinematic rotations. copyright 1998 The American Physical Society

  19. Investigation of acceleration effects on missile aerodynamics using computational fluid dynamics

    CSIR Research Space (South Africa)

    Gledhill, Irvy MA

    2009-01-01

    Full Text Available In this paper the authors describe the implementation and validation of arbitrarily moving reference frames in the block-structured CFD-code EURANUS. The paper also present results from calculations on two applications involving accelerating...

  20. Frame on frames: an annotated bibliography

    International Nuclear Information System (INIS)

    Wright, T.; Tsao, H.J.

    1983-01-01

    The success or failure of any sample survey of a finite population is largely dependent upon the condition and adequacy of the list or frame from which the probability sample is selected. Much of the published survey sampling related work has focused on the measurement of sampling errors and, more recently, on nonsampling errors to a lesser extent. Recent studies on data quality for various types of data collection systems have revealed that the extent of the nonsampling errors far exceeds that of the sampling errors in many cases. While much of this nonsampling error, which is difficult to measure, can be attributed to poor frames, relatively little effort or theoretical work has focused on this contribution to total error. The objective of this paper is to present an annotated bibliography on frames with the hope that it will bring together, for experimenters, a number of suggestions for action when sampling from imperfect frames and that more attention will be given to this area of survey methods research

  1. FULL ELECTROMAGNETIC SIMULATION OF COHERENT SYNCHROTRON RADIATION VIA THE LORENTZ-BOOSTED FRAME APPROACH

    International Nuclear Information System (INIS)

    Fawley, William M.; Vay, Jean-Luc

    2010-01-01

    Numerical simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz-boosted frame. Orders of magnitude speedup has been demonstrated for simulations from first principles of laser-plasma accelerator, free electron laser, and particle beams interacting with electron clouds. Here we address the application of the Lorentz-boosted frame approach to coherent synchrotron radiation (CSR), which can be strongly present in bunch compressor chicanes. CSR is particularly relevant to the next generation of x-ray light sources and is simultaneously difficult to simulate in the lab frame because of the large ratio of scale lengths. It can increase both the incoherent and coherent longitudinal energy spread, effects that often lead to an increase in transverse emittance. We have adapted the WARP code to simulate CSR emission along a simple dipole bend. We present some scaling arguments for the possible computational speed up factor in the boosted frame and initial 3D simulation results.

  2. Cosmic ray acceleration by stellar wind. Simulation for heliosphere

    International Nuclear Information System (INIS)

    Petukhov, S.I.; Turpanov, A.A.; Nikolaev, V.S.

    1985-01-01

    The solar wind deceleration by the interstellar medium may result in the existence of the solar wind terminal shock. In this case a certain fraction of thermal particles after being heated at the shock would obtain enough energy to be injected to the regular acceleration process. An analytical solution for the spectrum in the frame of a simplified model that includes particle acceleration at the shock front and adiabatic cooling inside the stellar wind cavity has been derived. It is shown that the acceleration of the solar wind particles at the solar wind terminal shock is capable of providing the total flux, spectrum and radial gradients of the low-energy protons close to one observed in the interplanetary space

  3. Dose linearity and uniformity of Siemens ONCOR impression plus linear accelerator designed for step-and-shoot intensity-modulated radiation therapy

    Directory of Open Access Journals (Sweden)

    Bhangle Janhavi

    2007-01-01

    Full Text Available For step-and-shoot type delivery of intensity-modulated radiation therapy (IMRT, beam stability characteristics during the first few monitor units need to be investigated to ensure the planned dose delivery. This paper presents the study done for Siemens ONCOR impression plus linear accelerator before commissioning it for IMRT treatment. The beam stability for 6 and 15 MV in terms of dose monitor linearity, monitor unit stability and beam uniformity is investigated in this work. Monitor unit linearity is studied using FC65G chamber for the range 1-100 MU. The dose per MU is found to be linear for small monitor units down to 1 MU for both 6 and 15 MV beams. The monitor unit linearity is also studied with portal imaging device for the range 1-20 MU for 6 MV beam. The pixel values are within ±1σ confidence level up to 2 MU; for 1 MU, the values are within ±2σ confidence level. The flatness and symmetry analysis is done for both energies in the range of 1-10 MU with Kodak diagnostic films. The flatness and symmetry are found to be within ±3% up to 2 MU for 6 MV and up to 3 MU for 15 MV.

  4. Dose linearity and uniformity of Siemens ONCOR impression plus linear accelerator designed for step-and-shoot intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Bhangle, Janhavi R.; Sathiya Narayanan, V.K.; Deshpande, Shrikant A.

    2007-01-01

    For step-and-shoot type delivery of intensity-modulated radiation therapy (IMRT), beam stability characteristics during the first few monitor units need to be investigated to ensure the planned dose delivery. This paper presents the study done for Siemens ONCOR impression plus linear accelerator before commissioning it for IMRT treatment. The beam stability for 6 and 15 MV in terms of dose monitor linearity, monitor unit stability and beam uniformity is investigated in this work. Monitor unit linearity is studied using FC65G chamber for the range 1-100 MU. The dose per MU is found to be linear for small monitor units down to 1 MU for both 6 and 15 MV beams. The monitor unit linearity is also studied with portal imaging device for the range 1-20 MU for 6 MV beam. The pixel values are within ±1σ confidence level up to 2 MU; for 1 MU, the values are within ±2σ confidence level. The flatness and symmetry analysis is done for both energies in the range of 1-10 MU with Kodak diagnostic films. The flatness and symmetry are found to be within ±3% up to 2 MU for 6 MV and up to 3 MU for 15 MV. (author)

  5. Investigation of Non-Uniform Rust Distribution and Its Effects on Corrosion Induced Cracking in Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Sutrisno Wahyuniarsih

    2017-01-01

    Full Text Available Uniform corrosion still widely used by a lot of researchers and engineers to analyze the corrosion induced cracking. However, in practice, corrosion process occurred non-uniformly. The part nearest to the exposed surface is more likely to have faster corrosion initiation compared with other regions. This research is mainly focused on investigating the effect of non-uniform rust distribution to cover cracking in reinforced concrete. An experimental test performed using accelerated corrosion test by using 5% NaCl solution and applied a constant electric current to the concrete samples. The rust distribution and measurement were observed by using a digital microscope. Based on the experimental result, it was found that the rust was distributed in a non-uniform pattern. As a result, the cracks also formed non-uniformly along the perimeter of steel bar. At the last part of this paper, a simulation result of concrete cracking induced by non-uniform corrosion is presented. The result compared with a simulation using uniform corrosion assumption to investigate the damage pattern of each model. The simulation result reveals stress evolution due to rust expansion which leads to concrete cracking. Furthermore, a comparison of stresses induced by non-uniform corrosion and uniform corrosion indicates that non-uniform corrosion could lead to earlier damage to the structure which is specified by the formation and propagation of the crack.

  6. Transverse wakefield effects in the two-beam accelerator

    International Nuclear Information System (INIS)

    Selph, F.; Sessler, A.

    1986-01-01

    Transverse wakefield effects in the high-gradient accelerating structure of the two-beam accelerator (TBA) are analyzed theoretically using three different models. The first is a very simple two-particle model, the second is for a beam with uniform charge distribution, constant betatron wavelength, and a linear wake approximation. Both of these models give analytic scaling laws. The third model has a Gaussian beam (represented by 11 superparticles), energy variation across the bunch, acceleration, variation of betatron focusing with energy, and variation of the wakefield from linearity. The three models are compared, and the third model is used to explore the wakefield effects when accelerator parameters such as energy, energy spread, injection energy, accelerating gradient, and betatron wavelength are varied. Also explored are the sensitivity of the beam to the wakefield profile to the longitudinal charge distribution. Finally, in consideration of wakefield effects, possible parameters of a TBA are presented. (orig./HSI)

  7. Zero-point field in a circular-motion frame

    International Nuclear Information System (INIS)

    Kim, S.K.; Soh, K.S.; Yee, J.H.

    1987-01-01

    The energy spectrum of zero-point fields of a massless scalar field observed by a detector in circular motion is studied by analyzing the Wightman function. It is shown to be quite different from the Planck spectrum which would have been expected from the result of a uniformly accelerated detector. In a nonrelativistic limit zero-point fields with frequencies only up to the first harmonics of the circular-motion frequency contribute dominantly. In an extremely relativistic case the energy spectrum is dominated by a particular pole in the complex proper-time plane

  8. General man-machine interface used in accelerators controls

    International Nuclear Information System (INIS)

    Boutheon, M.; Di Maio, F.; Pace, A.

    1992-01-01

    A large community is now using Workstations as Accelerators Computer Controls Interface, through the concepts of windows - menus - synoptics - icons. Some standards were established for the CERN-PS control systems rejuvenation. The Booster-to-PS transfer and injection process is now entirely operated with these tools. This application constitutes a global environment providing the users with the controls, analysis, visualization of a part of an accelerator. Individual commands, measurements, and specialized programs including complex treatments are available in a homogeneous frame. Some months of experience in current operation have shown that this model can be extended to the whole project. (author)

  9. Intermediate accelerated solutions as generic late-time attractors in a modified Jordan-Brans-Dicke theory

    Energy Technology Data Exchange (ETDEWEB)

    Cid, Antonella [Grupo de Cosmología y Gravitación GCG-UBB and Departamento de Física, Universidad del Bío-Bío, Casilla 5-C, Concepción (Chile); Leon, Genly [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4950, Valparaíso (Chile); Leyva, Yoelsy, E-mail: acidm@ubiobio.cl, E-mail: genly.leon@ucv.cl, E-mail: yoelsy.leyva@uta.cl [Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá, Casilla 7-D, Arica (Chile)

    2016-02-01

    In this paper we investigate the evolution of a Jordan-Brans-Dicke scalar field, Φ, with a power-law potential in the presence of a second scalar field, φ, with an exponential potential, in both the Jordan and the Einstein frames. We present the relation of our model with the induced gravity model with power-law potential and the integrability of this kind of models is discussed when the quintessence field φ is massless, and has a small velocity. The fact that for some fine-tuned values of the parameters we may get some integrable cosmological models, makes our choice of potentials very interesting. We prove that in Jordan-Brans-Dicke theory, the de Sitter solution is not a natural attractor. Instead, we show that the attractor in the Jordan frame corresponds to an ''intermediate accelerated'' solution of the form a(t) ≅ e{sup α{sub 1} t{sup p{sup {sub 1}}}}, as t → ∞ where α{sub 1} > 0 and 0 < p{sub 1} < 1, for a wide range of parameters. Furthermore, when we work in the Einstein frame we get that the attractor is also an ''intermediate accelerated'' solution of the form a(t) ≅ e{sup α{sub 2} tp{sub 2}} as t → ∞ where α{sub 2} > 0 and 0frame. In the special case of a quadratic potential in the Jordan frame, or for a constant potential in the Einstein's frame, the above intermediate solutions are of saddle type. These results were proved using the center manifold theorem, which is not based on linear approximation. Finally, we present a specific elaboration of our extension of the induced gravity model in the Jordan frame, which corresponds to a particular choice of a linear potential of Φ. The dynamical system is then reduced to a two dimensional one, and the late-time attractor is linked with the exact solution found for the induced gravity model. In this example the ''intermediate accelerated

  10. Intermediate accelerated solutions as generic late-time attractors in a modified Jordan-Brans-Dicke theory

    International Nuclear Information System (INIS)

    Cid, Antonella; Leon, Genly; Leyva, Yoelsy

    2016-01-01

    In this paper we investigate the evolution of a Jordan-Brans-Dicke scalar field, Φ, with a power-law potential in the presence of a second scalar field, φ, with an exponential potential, in both the Jordan and the Einstein frames. We present the relation of our model with the induced gravity model with power-law potential and the integrability of this kind of models is discussed when the quintessence field φ is massless, and has a small velocity. The fact that for some fine-tuned values of the parameters we may get some integrable cosmological models, makes our choice of potentials very interesting. We prove that in Jordan-Brans-Dicke theory, the de Sitter solution is not a natural attractor. Instead, we show that the attractor in the Jordan frame corresponds to an ''intermediate accelerated'' solution of the form a(t) ≅ e α 1  t p 1 , as t → ∞ where α 1  > 0 and 0 < p 1  < 1, for a wide range of parameters. Furthermore, when we work in the Einstein frame we get that the attractor is also an ''intermediate accelerated'' solution of the form a(t) ≅ e α 2  tp 2 as t → ∞ where α 2  > 0 and 0

    frame. In the special case of a quadratic potential in the Jordan frame, or for a constant potential in the Einstein's frame, the above intermediate solutions are of saddle type. These results were proved using the center manifold theorem, which is not based on linear approximation. Finally, we present a specific elaboration of our extension of the induced gravity model in the Jordan frame, which corresponds to a particular choice of a linear potential of Φ. The dynamical system is then reduced to a two dimensional one, and the late-time attractor is linked with the exact solution found for the induced gravity model. In this example the ''intermediate accelerated'' solution does not exist, and the attractor

  11. Reserve seismic capacity determination of a nuclear power plant braced frame with piping

    International Nuclear Information System (INIS)

    Nelson, T.A.

    1979-01-01

    A typical diagonal braced steel frame was developed to determine the amount of reserve capacity that is available beyond elastic design levels. The frame was analyzed first using elastic static and dynamic analyses. The loadings included dead and live load, an equivalent static lateral earthquake load, two response spectra and a suite of eight earthquake time history records. The response spectra used were the Housner and Regulatory Guide 1.60. The time histories represented different site conditions, distances to causative faults and magnitudes. The lateral static load and Housner spectrum represent vintage design criteria, while the R.G. 1.60 and time history analyses reflect current methodology. The elastic limit responses of the structure were determined along with the accompanying threshold peak ground accelerations (threshold g values). The frame was then analyzed using the program DRAIN-2D to perform two-dimensional elastic--plastic analyses for the eight time histories

  12. Behaviour of Strengthened RC Frames with Eccentric Steel Braced Frames

    Science.gov (United States)

    Kamanli, Mehmet; Unal, Alptug

    2017-10-01

    After devastating earthquakes in recent years, strengthening of reinforced concrete buildings became an important research topic. Reinforced concrete buildings can be strengthened by steel braced frames. These steel braced frames may be made of concentrically or eccentrically indicated in Turkish Earthquake Code 2007. In this study pushover analysis of the 1/3 scaled 1 reinforced concrete frame and 1/3 scaled 4 strengthened reinforced concrete frames with internal eccentric steel braced frames were conducted by SAP2000 program. According to the results of the analyses conducted, load-displacement curves of the specimens were compared and evaluated. Adding eccentric steel braces to the bare frame decreased the story drift, and significantly increased strength, stiffness and energy dissipation capacity. In this strengthening method lateral load carrying capacity, stiffness and dissipated energy of the structure can be increased.

  13. Approximately dual frames in Hilbert spaces and applications to Gabor frames

    OpenAIRE

    Christensen, Ole; Laugesen, Richard S.

    2011-01-01

    Approximately dual frames are studied in the Hilbert space setting. Approximate duals are easier to construct than classical dual frames, and can be tailored to yield almost perfect reconstruction. Bounds on the deviation from perfect reconstruction are obtained for approximately dual frames constructed via perturbation theory. An alternative bound is derived for the rich class of Gabor frames, by using the Walnut representation of the frame operator to estimate the deviation from equality in...

  14. Framing the frame: How task goals determine the likelihood and direction of framing effects

    OpenAIRE

    Todd McElroy; John J. Seta

    2007-01-01

    We examined how the goal of a decision task influences the perceived positive, negative valence of the alternatives and thereby the likelihood and direction of framing effects. In Study 1 we manipulated the goal to increase, decrease or maintain the commodity in question and found that when the goal of the task was to increase the commodity, a framing effect consistent with those typically observed in the literature was found. When the goal was to decrease, a framing effect opposite to the ty...

  15. Hydrodynamical expansion with frame independence symmetry in high energy multiparticle production

    International Nuclear Information System (INIS)

    Chiu, C.B.; Sudarshan, E.C.G.; Wang, K.

    1974-01-01

    The space--time development of the hadronic system formed immediately after the high energy hadron collision is described with the following picture. Initially the system is highly compressed along the longitudinal direction. The sudden relaxation of this compression leads to a violent acceleration along this direction and perhaps a weak acceleration along the transverse direction. When these accelerations cease, it is proposed that the system acquires a frame independence symmetry with its further expansion governed by the hydrodynamic equation of motion. Within the scheme, this symmetry provides a natural mechanism which eventually leads to a flat inclusive longitudinal rapidity distribution and it also admits a sharp cutoff in the inclusive transverse momentum distribution. The latter is to be contrasted with the prediction of Landau's model, where the average transverse momentum increases with c.m. energy W, [p/sub T/] -W/sup 1 / 6 ./. Finally effects of clustering can also be easily incorporated within the framework. (U.S.)

  16. Mars Science Laboratory Frame Manager for Centralized Frame Tree Database and Target Pointing

    Science.gov (United States)

    Kim, Won S.; Leger, Chris; Peters, Stephen; Carsten, Joseph; Diaz-Calderon, Antonio

    2013-01-01

    The FM (Frame Manager) flight software module is responsible for maintaining the frame tree database containing coordinate transforms between frames. The frame tree is a proper tree structure of directed links, consisting of surface and rover subtrees. Actual frame transforms are updated by their owner. FM updates site and saved frames for the surface tree. As the rover drives to a new area, a new site frame with an incremented site index can be created. Several clients including ARM and RSM (Remote Sensing Mast) update their related rover frames that they own. Through the onboard centralized FM frame tree database, client modules can query transforms between any two frames. Important applications include target image pointing for RSM-mounted cameras and frame-referenced arm moves. The use of frame tree eliminates cumbersome, error-prone calculations of coordinate entries for commands and thus simplifies flight operations significantly.

  17. Hydrodynamical expansion with frame-independence symmetry in high-energy multiparticle production

    International Nuclear Information System (INIS)

    Chiu, C.B.; Sudarshan, E.; Wang, K.

    1975-01-01

    We describe the space-time development of the hardronic system formed immediately after the high-energy hadron collision with the following picture. Initially the system is highly compressed along the longitudinal direction. The sudden relaxation of this compression leads to a violent acceration along this direction and perhaps a weak acceleration along the transverse direction. When these accelerations cease, we propose that the system acquires certain frame-independence symmetry with its further expansion governed by the hydrodynamic equation of motion. Within our scheme, this symmetry provides a natural mechanism which eventually leads to a flat inclusive longitudinal rapidity distribution and it also admits a sharp cutoff in the inclusive transverse momentum distribution. These features differ from those of Landau's model

  18. Behaviour of Strengthened RC Frames with Eccentric Steel Braced Frames

    Directory of Open Access Journals (Sweden)

    Kamanli Mehmet

    2017-01-01

    Full Text Available After devastating earthquakes in recent years, strengthening of reinforced concrete buildings became an important research topic. Reinforced concrete buildings can be strengthened by steel braced frames. These steel braced frames may be made of concentrically or eccentrically indicated in Turkish Earthquake Code 2007. In this study pushover analysis of the 1/3 scaled 1 reinforced concrete frame and 1/3 scaled 4 strengthened reinforced concrete frames with internal eccentric steel braced frames were conducted by SAP2000 program. According to the results of the analyses conducted, load-displacement curves of the specimens were compared and evaluated. Adding eccentric steel braces to the bare frame decreased the story drift, and significantly increased strength, stiffness and energy dissipation capacity. In this strengthening method lateral load carrying capacity, stiffness and dissipated energy of the structure can be increased.

  19. Treatment planning capability assessment of a beam shaping assembly for accelerator-based BNCT

    International Nuclear Information System (INIS)

    Herrera, M.S.; González, S.J.; Burlon, A.A.; Minsky, D.M.; Kreiner, A.J.

    2011-01-01

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT) a theoretical study was performed to assess the treatment planning capability of different configurations of an optimized beam shaping assembly for such a facility. In particular this study aims at evaluating treatment plans for a clinical case of Glioblastoma.

  20. Gravitomagnetic Acceleration of Black Hole Accretion Disk Matter to Polar Jets

    Science.gov (United States)

    Poirier, John; Mathews, Grant

    2015-04-01

    It is shown that the motion of the neutral masses in an accretion disk orbiting a black hole creates a magnetic-like (gravitomagnetic) field that vertically accelerates neutral particles near the accretion disk away from the disk and then inward toward the axis of the accretion disk. Moreover, as the accelerated material nears the axis, a frame-dragging effect twists the trajectories around the axis thus contributing to the formation of a narrow polar jet emanating from the poles.

  1. The effect of increased irradiation uniformity on imprinting by 351-nm laser light

    International Nuclear Information System (INIS)

    Boehly, T.R.; Smalyuk, V.A.; Meyerhofer, D.D.; Knauer, J.P.; Bradley, D.K.; Verdon, C.P.; Kalantar, D.

    1997-01-01

    The acceleration-driven growth of perturbations initially seeded (or imprinted) by irradiation nonuniformities is a major concern for direct-drive ICF. We report on experiments where unperturbed, CH 2 targets were irradiated with 3-ns square pulses at 2x10 14 W/cm 2 using five overlapped UV beams. The uniformity of these beams was varied and subsequent unstable growth of irradiation imprinting was observed using time-gated x-radiography. We demonstrate that increased irradiation uniformity reduces imprinting, and we show the beneficial effects of distributed polarization rotators a new beam-smoothing device. In addition, we discuss experiments using a ' perturbing beam' to study the time dependence of imprinting. copyright 1997 American Institute of Physics

  2. Relativistic effects in local inertial frames including PPN effects

    International Nuclear Information System (INIS)

    Shahid-Saless, B.

    1986-01-01

    In this dissertation they use the concept of a generalized Fermi frame to describe the relativistic effects on a body placed in a local inertial frame of reference due to local and distant sources of gravitation. They have considered, in particular, a model, consisted of two spherically symmetric gravitating sources, moving in circular orbits around a common barycenter where one of the bodies is chosen to be the local and the other the distant one. This has been done in the Parametrized-Post-Newtonian formalism using the slow motion, weak field approximation. The PPN parameters used are γ, β, zeta 1 and zeta 2 . They show that the main relativistic effect on a local satellite is described by the Schwarzchild field of the local body and the nonlinear term corresponding to the self-interaction of the local source itself. There are also much smaller terms that are proportional to the product of the potentials of local and distant bodies and distant body's self interactions. The spatial axis of the local frame undergoes Geodetic precession. Effects involving the parameters zeta 1 and zeta 2 seem to be slightly too small to be observable at the present time. In addition they have found accelerations that vanish in the general relativity limit

  3. Cosmic ray acceleration by large scale galactic shocks

    International Nuclear Information System (INIS)

    Cesarsky, C.J.; Lagage, P.O.

    1987-01-01

    The mechanism of diffusive shock acceleration may account for the existence of galactic cosmic rays detailed application to stellar wind shocks and especially to supernova shocks have been developed. Existing models can usually deal with the energetics or the spectral slope, but the observed energy range of cosmic rays is not explained. Therefore it seems worthwhile to examine the effect that large scale, long-lived galactic shocks may have on galactic cosmic rays, in the frame of the diffusive shock acceleration mechanism. Large scale fast shocks can only be expected to exist in the galactic halo. We consider three situations where they may arise: expansion of a supernova shock in the halo, galactic wind, galactic infall; and discuss the possible existence of these shocks and their role in accelerating cosmic rays

  4. Multivariate wavelet frames

    CERN Document Server

    Skopina, Maria; Protasov, Vladimir

    2016-01-01

    This book presents a systematic study of multivariate wavelet frames with matrix dilation, in particular, orthogonal and bi-orthogonal bases, which are a special case of frames. Further, it provides algorithmic methods for the construction of dual and tight wavelet frames with a desirable approximation order, namely compactly supported wavelet frames, which are commonly required by engineers. It particularly focuses on methods of constructing them. Wavelet bases and frames are actively used in numerous applications such as audio and graphic signal processing, compression and transmission of information. They are especially useful in image recovery from incomplete observed data due to the redundancy of frame systems. The construction of multivariate wavelet frames, especially bases, with desirable properties remains a challenging problem as although a general scheme of construction is well known, its practical implementation in the multidimensional setting is difficult. Another important feature of wavelet is ...

  5. New class of accelerating black hole solutions

    International Nuclear Information System (INIS)

    Camps, Joan; Emparan, Roberto

    2010-01-01

    We construct several new families of vacuum solutions that describe black holes in uniformly accelerated motion. They generalize the C metric to the case where the energy density and tension of the strings that pull (or push) on the black holes are independent parameters. These strings create large curvatures near their axis and when they have infinite length they modify the asymptotic properties of the spacetime, but we discuss how these features can be dealt with physically, in particular, in terms of 'wiggly cosmic strings'. We comment on possible extensions and extract lessons for the problem of finding higher-dimensional accelerating black hole solutions.

  6. The effect of axial loads on free vibration of symmetric frame structures using continuous system method

    Directory of Open Access Journals (Sweden)

    Elham Ghandi

    2016-09-01

    Full Text Available The free vibration of frame structures has been usually studied in literature without considering the effect of axial loads. In this paper, the continuous system method is employed to investigate this effect on the free flexural and torsional vibration of two and three dimensional symmetric frames. In the continuous system method, in approximate analysis of buildings, commonly, the structure is replaced by an equivalent beam which matches the dominant characteristics of the structure. Accordingly, the natural frequencies of the symmetric frame structures are obtained through solving the governing differential equation of the equivalent beam whose stiffness and mass are supposed to be uniformly distributed along the length. The corresponding axial load applied to the replaced beam is calculated based on the total weight and the number of stories of the building. A numerical example is presented to show the simplicity and efficiency of the proposed solution.

  7. Frames and outer frames for Hilbert C^*-modules

    OpenAIRE

    Arambašić, Ljiljana; Bakić, Damir

    2015-01-01

    The goal of the present paper is to extend the theory of frames for countably generated Hilbert $C^*$-modules over arbitrary $C^*$-algebras. In investigating the non-unital case we introduce the concept of outer frame as a sequence in the multiplier module $M(X)$ that has the standard frame property when applied to elements of the ambient module $X$. Given a Hilbert $\\A$-module $X$, we prove that there is a bijective correspondence of the set of all adjointable surjections from the generalize...

  8. Gravitomagnetic acceleration from black hole accretion disks

    International Nuclear Information System (INIS)

    Poirier, J; Mathews, G J

    2016-01-01

    We demonstrate how the motion of the neutral masses in an accretion disk orbiting a black hole creates a general-relativistic magnetic-like (gravitomagnetic) field that vertically accelerates neutral particles near an accretion disk upward and then inward toward the axis of the accretion disk. Even though this gravitomagnetic field is not the only mechanism contributing to the production of jets, it presents a novel means to identify one general relativistic effect from a much more complicated problem. In addition, as the accelerated material above or below the accretion disk nears the axis with a nearly vertical direction, a frame-dragging effect twists the trajectories around the axis thus contributing to the collimation of the jet. (note)

  9. Gravitomagnetic acceleration from black hole accretion disks

    Science.gov (United States)

    Poirier, J.; Mathews, G. J.

    2016-05-01

    We demonstrate how the motion of the neutral masses in an accretion disk orbiting a black hole creates a general-relativistic magnetic-like (gravitomagnetic) field that vertically accelerates neutral particles near an accretion disk upward and then inward toward the axis of the accretion disk. Even though this gravitomagnetic field is not the only mechanism contributing to the production of jets, it presents a novel means to identify one general relativistic effect from a much more complicated problem. In addition, as the accelerated material above or below the accretion disk nears the axis with a nearly vertical direction, a frame-dragging effect twists the trajectories around the axis thus contributing to the collimation of the jet.

  10. Relativity and accelerator engineering

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2017-09-01

    From a geometrical viewpoint, according to the theory of relativity, space and time constitute a four-dimensional continuum with pseudo-Euclidean structure. This has recently begun to be a practically important statement in accelerator physics. An X-ray Free Electron Laser (XFEL) is in fact the best, exciting example of an engineering system where improvements in accelerator technology makes it possible to develop ultrarelativistic macroscopic objects with an internal fine structure, and the theory of relativity plays an essential role in their description. An ultrarelativistic electron bunch modulated at nanometer-scale in XFELs has indeed a macroscopic finite-size of order of 10 μm. Its internal, collective structure is characterized in terms of a wave number vector. Here we will show that a four-dimensional geometrical approach, unusual in accelerator physics, is needed to solve problems involving the emission of radiation from an ultrarelativistic modulated electron beam accelerating along a curved trajectory. We will see that relativistic kinematics enters XFEL physics in a most fundamental way through the so-called Wigner rotation of the modulation wave number vector, which is closely associated to the relativity of simultaneity. If not taken into account, relativistic kinematics effects would lead to a strong qualitative disagreement between theory and experiments. In this paper, several examples of relativistic kinematics effects, which are important for current and future XFEL operation, are studied. The theory of relativity is applied by providing details of the clock synchronization procedure within the laboratory frame. This approach, exploited here but unusual in literature, is rather ''practical'', and should be acceptable to accelerator physicists.

  11. Non uniform nature of recorded ground accelerations at dam foundation interface

    Energy Technology Data Exchange (ETDEWEB)

    Ghaemian, Mohsen; Gilani, Morteza Sohrabi [Sharif University of Technology, Tehran, (Iran, Islamic Republic of); Noorzad, Ali [Power and Water University of Technology, Tehran, (Iran, Islamic Republic of)

    2010-07-01

    The Karun III is a double curved concrete arch dam located in Iran which was used to investigate earthquake motions and dam responses. This paper presented the study of the Karun III dam foundation interface. Using an array of 15 accelerometers, two major events that occurred on 2007.11.20 and 2007.11.21 were recorded during dam operation with a PGA at crest of 0.312 g and 0.109.g respectively. A finite element model of Karun III dam was performed. The response of the Karun III dam during the 2007 earthquake was investigated using the NSAD-DRI program. It was found that the motion of the dam foundation interface is non-uniform. There is a time shift and amplification at the abutment compared to those at the base of the dam. The results showed that the spatially varying earthquake assumption is in good agreement with the recorded displacement of the dam.

  12. Fast-acting calorimeter measures heat output of plasma gun accelerator

    Science.gov (United States)

    Dethlefson, R.; Larson, A. V.; Liebing, L.

    1967-01-01

    Calorimeter measures the exhaust energy from a shot of a pulsed plasma gun accelerator. It has a fast response time and requires only one measurement to determine the total energy. It uses a long ribbon of copper foil wound around a glass frame to form a reentrant cavity.

  13. The Acceleration of Charged Particles at a Spherical Shock Moving through an Irregular Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Giacalone, J. [Department of Planetary Sciences, University of Arizona, Tucson, AZ (United States)

    2017-10-20

    We investigate the physics of charged-particle acceleration at spherical shocks moving into a uniform plasma containing a turbulent magnetic field with a uniform mean. This has applications to particle acceleration at astrophysical shocks, most notably, to supernovae blast waves. We numerically integrate the equations of motion of a large number of test protons moving under the influence of electric and magnetic fields determined from a kinematically defined plasma flow associated with a radially propagating blast wave. Distribution functions are determined from the positions and velocities of the protons. The unshocked plasma contains a magnetic field with a uniform mean and an irregular component having a Kolmogorov-like power spectrum. The field inside the blast wave is determined from Maxwell’s equations. The angle between the average magnetic field and unit normal to the shock varies with position along its surface. It is quasi-perpendicular to the unit normal near the sphere’s equator, and quasi-parallel to it near the poles. We find that the highest intensities of particles, accelerated by the shock, are at the poles of the blast wave. The particles “collect” at the poles as they approximately adhere to magnetic field lines that move poleward from their initial encounter with the shock at the equator, as the shock expands. The field lines at the poles have been connected to the shock the longest. We also find that the highest-energy protons are initially accelerated near the equator or near the quasi-perpendicular portion of the shock, where the acceleration is more rapid.

  14. Novel gas target for laser wakefield accelerators

    Science.gov (United States)

    Aniculaesei, C.; Kim, Hyung Taek; Yoo, Byung Ju; Oh, Kyung Hwan; Nam, Chang Hee

    2018-02-01

    A novel gas target for interactions between high power lasers and gaseous medium, especially for laser wakefield accelerators, has been designed, manufactured, and characterized. The gas target has been designed to provide a uniform density profile along the central gas cell axis by combining a gas cell and slit nozzle. The gas density has been tuned from ˜1017 atoms/cm3 to ˜1019 atoms/cm3 and the gas target length can be varied from 0 to 10 cm; both changes can be made simultaneously while keeping the uniform gas profile. The gas density profile inside the gas cell has been measured using interferometry and validated using computational fluid dynamics.

  15. Probabilistic assessment of steel moment frames incremental collapse (ordinary, intermediate and special under earthquake

    Directory of Open Access Journals (Sweden)

    Kourosh Mehdizadeh

    2017-11-01

    Full Text Available Building collapse is a level of the structure performance in which the amount of financial and life loss is maximized, so this event could be the worst incident in the construction. Regarding to the possibility of destructive earthquakes in different parts of the world, detailed assessment of the structure's collapse has been one of the major challenges of the structural engineering. In this regard, offering models based on laboratory studies, considering the effective parameters and appropriate earthquakes could be a step towards achieving this goal. In this research, a five-story steel structure with a system of ordinary, intermediate and special moment frame (low, intermediate and high ductility has been designed based on the local regulations. In this study, the effect of resistance and stiffness deterioration of the structural elements based on the results of the laboratory models have been considered and the ductility role in the collapse capacity of steel moment frames has been investigated as probabilistic matter. For this purpose, incremental dynamic analysis has been done under 50 pairs of earthquake records proposing FEMA P695 instruction and fragility curves of various performance levels are developed. Results showed higher collapse capacity of special moment steel frame than the intermediate and ordinary moment frames. In the 50 percent probability level, the collapse capacity of special moment frame increased 34 % compared to the intermediate moment frame and 66 % to the ordinary moment frame. Also, the results showed that for different collapse spectral accelerations, the use of special moment frame instead of intermediate and ordinary moment frames reduces the collapse probability to 30 and 50 % respectively.

  16. On frame multiresolution analysis

    DEFF Research Database (Denmark)

    Christensen, Ole

    2003-01-01

    We use the freedom in frame multiresolution analysis to construct tight wavelet frames (even in the case where the refinable function does not generate a tight frame). In cases where a frame multiresolution does not lead to a construction of a wavelet frame we show how one can nevertheless...

  17. Beam emittance growth caused by transverse deflecting fields in a linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Chao, A W; Richter, B; Yao, C Y [Stanford Linear Accelerator Center, CA (USA)

    1980-12-01

    The effect of the beam-generated transverse deflecting fields on the emittance of an intense bunch of particles in a high-energy linear accelerator is analyzed in this paper. The equation of motion is solved by a perturbation method for cases of a coasting beam and a uniformly accelerated beam. The results are applied to obtain some design tolerance specifications for the recently proposed SLAC Single Pass Collider.

  18. Framed School--Frame Factors, Frames and the Dynamics of Social Interaction in School

    Science.gov (United States)

    Persson, Anders

    2015-01-01

    This paper aims to show how the Goffman frame perspective can be used in an analysis of school and education and how it can be combined, in such analysis, with the frame factor perspective. The latter emphasizes factors that are determined outside the teaching process, while the former stresses how actors organize their experiences and define…

  19. Uniformity testing: assessment of a centralized web-based uniformity analysis system.

    Science.gov (United States)

    Klempa, Meaghan C

    2011-06-01

    Uniformity testing is performed daily to ensure adequate camera performance before clinical use. The aim of this study is to assess the reliability of Beth Israel Deaconess Medical Center's locally built, centralized, Web-based uniformity analysis system by examining the differences between manufacturer and Web-based National Electrical Manufacturers Association integral uniformity calculations measured in the useful field of view (FOV) and the central FOV. Manufacturer and Web-based integral uniformity calculations measured in the useful FOV and the central FOV were recorded over a 30-d period for 4 cameras from 3 different manufacturers. These data were then statistically analyzed. The differences between the uniformity calculations were computed, in addition to the means and the SDs of these differences for each head of each camera. There was a correlation between the manufacturer and Web-based integral uniformity calculations in the useful FOV and the central FOV over the 30-d period. The average differences between the manufacturer and Web-based useful FOV calculations ranged from -0.30 to 0.099, with SD ranging from 0.092 to 0.32. For the central FOV calculations, the average differences ranged from -0.163 to 0.055, with SD ranging from 0.074 to 0.24. Most of the uniformity calculations computed by this centralized Web-based uniformity analysis system are comparable to the manufacturers' calculations, suggesting that this system is reasonably reliable and effective. This finding is important because centralized Web-based uniformity analysis systems are advantageous in that they test camera performance in the same manner regardless of the manufacturer.

  20. Target shape effects on monoenergetic GeV proton acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Chen Min; Yu Tongpu; Pukhov, Alexander [Institut fuer Theoretische Physik I, Heinrich-Heine-Universitaet Duesseldorf, 40225 Duesseldorf (Germany); Sheng Zhengming, E-mail: pukhov@tp1.uni-duesseldorf.d [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-04-15

    When a circularly polarized laser pulse interacts with a foil target, there are three stages: pre-hole-boring, hole-boring and light sail acceleration. We study the electron and ion dynamics in the first stage and find the minimum foil thickness requirement for a given laser intensity. Based on this analysis, we propose using a shaped foil for ion acceleration, whose thickness varies transversely to match the laser intensity. Then, the target evolves into three regions: the acceleration, transparency and deformation regions. In the acceleration region, the target can be uniformly accelerated producing a mono-energetic and spatially collimated ion beam. Detailed numerical simulations are performed to check the feasibility and robustness of this scheme, such as the influence of shape factors and surface roughness. A GeV mono-energetic proton beam is observed in three-dimensional particle-in-cell simulations when a laser pulse with a focus intensity of 10{sup 22} W cm{sup -2} is used. The energy conversion efficiency of the laser pulse to the accelerated proton beam with the simulation parameters is more than 23%.

  1. Target shape effects on monoenergetic GeV proton acceleration

    International Nuclear Information System (INIS)

    Chen Min; Yu Tongpu; Pukhov, Alexander; Sheng Zhengming

    2010-01-01

    When a circularly polarized laser pulse interacts with a foil target, there are three stages: pre-hole-boring, hole-boring and light sail acceleration. We study the electron and ion dynamics in the first stage and find the minimum foil thickness requirement for a given laser intensity. Based on this analysis, we propose using a shaped foil for ion acceleration, whose thickness varies transversely to match the laser intensity. Then, the target evolves into three regions: the acceleration, transparency and deformation regions. In the acceleration region, the target can be uniformly accelerated producing a mono-energetic and spatially collimated ion beam. Detailed numerical simulations are performed to check the feasibility and robustness of this scheme, such as the influence of shape factors and surface roughness. A GeV mono-energetic proton beam is observed in three-dimensional particle-in-cell simulations when a laser pulse with a focus intensity of 10 22 W cm -2 is used. The energy conversion efficiency of the laser pulse to the accelerated proton beam with the simulation parameters is more than 23%.

  2. High-Order Model and Dynamic Filtering for Frame Rate Up-Conversion.

    Science.gov (United States)

    Bao, Wenbo; Zhang, Xiaoyun; Chen, Li; Ding, Lianghui; Gao, Zhiyong

    2018-08-01

    This paper proposes a novel frame rate up-conversion method through high-order model and dynamic filtering (HOMDF) for video pixels. Unlike the constant brightness and linear motion assumptions in traditional methods, the intensity and position of the video pixels are both modeled with high-order polynomials in terms of time. Then, the key problem of our method is to estimate the polynomial coefficients that represent the pixel's intensity variation, velocity, and acceleration. We propose to solve it with two energy objectives: one minimizes the auto-regressive prediction error of intensity variation by its past samples, and the other minimizes video frame's reconstruction error along the motion trajectory. To efficiently address the optimization problem for these coefficients, we propose the dynamic filtering solution inspired by video's temporal coherence. The optimal estimation of these coefficients is reformulated into a dynamic fusion of the prior estimate from pixel's temporal predecessor and the maximum likelihood estimate from current new observation. Finally, frame rate up-conversion is implemented using motion-compensated interpolation by pixel-wise intensity variation and motion trajectory. Benefited from the advanced model and dynamic filtering, the interpolated frame has much better visual quality. Extensive experiments on the natural and synthesized videos demonstrate the superiority of HOMDF over the state-of-the-art methods in both subjective and objective comparisons.

  3. Initial Demonstration of 9-MHz Framing Camera Rates on the FAST UV Drive Laser Pulse Trains

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H. [Fermilab; Edstrom Jr., D. [Fermilab; Ruan, J. [Fermilab

    2016-10-09

    We report the configuration of a Hamamatsu C5680 streak camera as a framing camera to record transverse spatial information of green-component laser micropulses at 3- and 9-MHz rates for the first time. The latter is near the time scale of the ~7.5-MHz revolution frequency of the Integrable Optics Test Accelerator (IOTA) ring and its expected synchroton radiation source temporal structure. The 2-D images are recorded with a Gig-E readout CCD camera. We also report a first proof of principle with an OTR source using the linac streak camera in a semi-framing mode.

  4. Network-based H.264/AVC whole frame loss visibility model and frame dropping methods.

    Science.gov (United States)

    Chang, Yueh-Lun; Lin, Ting-Lan; Cosman, Pamela C

    2012-08-01

    We examine the visual effect of whole frame loss by different decoders. Whole frame losses are introduced in H.264/AVC compressed videos which are then decoded by two different decoders with different common concealment effects: frame copy and frame interpolation. The videos are seen by human observers who respond to each glitch they spot. We found that about 39% of whole frame losses of B frames are not observed by any of the subjects, and over 58% of the B frame losses are observed by 20% or fewer of the subjects. Using simple predictive features which can be calculated inside a network node with no access to the original video and no pixel level reconstruction of the frame, we developed models which can predict the visibility of whole B frame losses. The models are then used in a router to predict the visual impact of a frame loss and perform intelligent frame dropping to relieve network congestion. Dropping frames based on their visual scores proves superior to random dropping of B frames.

  5. Framing Failures in Wood-Frame Hip Roofs under Extreme Wind Loads

    Directory of Open Access Journals (Sweden)

    Sarah A. Stevenson

    2018-02-01

    Full Text Available Wood-frame residential roof failures are among the most common and expensive types of wind damage. Hip roofs are commonly understood to be more resilient during extreme wind in relation to gable roofs. However, inspection of damage survey data from recent tornadoes has revealed a previously unstudied failure mode in which hip roofs suffer partial failure of the framing structure. In the current study, evidence of partial framing failures and statistics of their occurrence are explored and discussed, while the common roof design and construction practice are reviewed. Two-dimensional finite element models are developed to estimate the element-level load effects on hip roof trusses and stick-frame components. The likelihood of failure in each member is defined based on relative demand-to-capacity ratios. Trussed and stick-frame structures are compared to assess the relative performance of the two types of construction. The present analyses verify the common understanding that toenailed roof-to-wall connections are likely to be the most vulnerable elements in the structure of a wood-frame hip roof. However, the results also indicate that certain framing members and connections display significant vulnerability under the same wind uplift, and the possibility of framing failure is not to be discounted. Furthermore, in the case where the roof-to-wall connection uses hurricane straps, certain framing members and joints become the likely points of failure initiation. The analysis results and damage survey observations are used to expand the understanding of wood-frame residential roof failures, as they relate to the Enhanced Fujita Scale and provide assessment of potential gaps in residential design codes.

  6. Energy Balance in an Electrostatic Accelerator

    OpenAIRE

    Zolotorev, Max S.; McDonald, Kirk T.

    2000-01-01

    The principle of an electrostatic accelerator is that when a charge e escapes from a conducting plane that supports a uniform electric field of strength E_0, then the charge gains energy e E_0 d as it moves distance d from the plane. Where does this energy come from? We that the mechanical energy gain of the electron is balanced by the decrease in the electrostatic field energy of the system.

  7. Mandatory School Uniforms.

    Science.gov (United States)

    Cohn, Carl A.

    1996-01-01

    Shortly after implementing a mandatory school uniform policy, the Long Beach (California) Public Schools can boast 99% compliance and a substantial reduction in school crime. The uniforms can't be confused with gang colors, save parents money, and help identify outsiders. A sidebar lists ingredients for a mandatory uniform policy. (MLH)

  8. Accelerating and storing polarized hadron beams

    International Nuclear Information System (INIS)

    Teng, L.C.

    1990-10-01

    Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power in pp elastic scattering remains high, why hyperons are produced with high polarizations etc. It is, therefore, interesting to investigate the possibilities of accelerating and storing polarized beams in high energy colliders. On the technical side the recent understanding and confirmation of the actions of partial and multiple Siberian snakes made it possible to contemplate accelerating and storing polarized hadron beams to multi-TeV energies. In this paper, we will examine the equipment, the operation and the procedure required to obtain colliding beams of polarized protons at TeV energies

  9. When message-frame fits salient cultural-frame, messages feel more persuasive

    OpenAIRE

    Uskul, Ayse K.; Oyserman, Daphna

    2010-01-01

    The present study examines the persuasive effects of tailored health messages comparing those tailored to match (versus not match) both chronic cultural frame and momentarily salient cultural frame. Evidence from two studies (Study 1: n = 72 European Americans; Study 2: n = 48 Asian Americans) supports the hypothesis that message persuasiveness increases when chronic cultural frame, health message tailoring and momentarily salient cultural frame all match. The hypothesis was tested using a me...

  10. Special relativity in general frames from particles to astrophysics

    CERN Document Server

    Gourgoulhon, Éric

    2013-01-01

    Special relativity is the basis of many fields in modern physics: particle physics, quantum field theory, high-energy astrophysics, etc. This theory is presented here by adopting a four-dimensional point of view from the start. An outstanding feature of the book is that it doesn’t restrict itself to inertial frames but considers accelerated and rotating observers. It is thus possible to treat physical effects such as the Thomas precession or the Sagnac effect in a simple yet precise manner. In the final chapters, more advanced topics like tensorial fields in spacetime, exterior calculus and relativistic hydrodynamics are addressed. In the last, brief chapter the author gives a preview of gravity and shows where it becomes incompatible with Minkowsky spacetime. Well illustrated and enriched by many historical notes, this book also presents many applications of special relativity, ranging from particle physics (accelerators, particle collisions, quark-gluon plasma) to astrophysics (relativistic jets, active g...

  11. Treatment planning capability assessment of a beam shaping assembly for accelerator-based BNCT.

    Science.gov (United States)

    Herrera, M S; González, S J; Burlon, A A; Minsky, D M; Kreiner, A J

    2011-12-01

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT) a theoretical study was performed to assess the treatment planning capability of different configurations of an optimized beam shaping assembly for such a facility. In particular this study aims at evaluating treatment plans for a clinical case of Glioblastoma. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. School Uniforms Redux.

    Science.gov (United States)

    Dowling-Sendor, Benjamin

    2002-01-01

    Reviews a recent decision in "Littlefield" by the 5th Circuit upholding a school uniform policy. Advises board member who wish to adopt a school uniform policy to solicit input from parents and students, research the experiences of other school districts with uniform policies, and articulate the interests they wish to promote through uniform…

  13. Value Framing: A Prelude to Software Problem Framing

    NARCIS (Netherlands)

    Wieringa, Roelf J.; Gordijn, Jaap; van Eck, Pascal; Cox, K.; Hall, J.G.; Rapanotti, L.

    2004-01-01

    Software problem framing is a way to find specifications for software. Software problem frames can be used to structure the environment of a software system (the machine) and specify desired software properties in such a way that we can show that software with these properties will help achieve the

  14. Transport and acceleration of the high-current ion beam in magneto-isolated gap

    International Nuclear Information System (INIS)

    Karas', V.I.; Kornilov, E.A.; Manuilenko, O.V.; Fedorovskaya, O.V.; Tarakanov, V.P.

    2015-01-01

    The possibility of transportation and acceleration of the high-current ion beam in the magneto-isolated gap has been demonstrated. Found the parameters of the system and beams (the magnetic field produced by the coils with opposing currents, the size of the system, and the parameters of the beams), under which the uniform acceleration of the high-current ion beam all along the gap length is realized. It is shown that the quality of the ion beam, during transport and acceleration, at the exit of the gap is acceptable for many technological applications.

  15. Molecular frame and recoil frame angular distributions in dissociative photoionization of small molecules

    International Nuclear Information System (INIS)

    Lucchese, R R; Carey, R; Elkharrat, C; Houver, J C; Dowek, D

    2008-01-01

    Photoelectron angular distributions in the dipole approximation can be written with respect to several different reference frames. A brief review of the molecular frame and recoil frame are given. Experimentally, one approach for obtaining such angular distributions is through angle-resolved coincidence measurements of dissociative ionization. If the system dissociates into two heavy fragments, then the recoil frame angular distribution can be measured. Computed molecular frame and recoil frame photoelectron angular distributions are compared to experimental data for the Cl 2p ionization of CH 3 Cl.

  16. Filtering SVM frame-by-frame binary classification in a detection framework

    NARCIS (Netherlands)

    Betancourt Arango, A.; Morerio, P.; Marcenaro, L.; Rauterberg, G.W.M.; Regazzoni, C.S.

    2015-01-01

    Classifying frames, or parts of them, is a common way of carrying out detection tasks in computer vision. However, frame by frame classification suffers from sudden significant variations in image texture, colour and luminosity, resulting in noise in the extracted features and consequently in the

  17. Linear particle accelerator

    International Nuclear Information System (INIS)

    Richards, J.A.

    1977-01-01

    A linear particle accelerator which provides a pulsed beam of charged particles of uniform energy is described. The accelerator is in the form of an evacuated dielectric tube, inside of which a particle source is located at one end of the tube, with a target or window located at the other end of the dielectric tube. Along the length of the tube are externally located pairs of metal plates, each insulated from each other in an insulated housing. Each of the plates of a pair are connected to an electrical source of voltage of opposed polarity, with the polarity of the voltage of the plates oriented so that the plate of a pair, nearer to the particle source, is of the opposed polarity to the charge of the particle emitted by the source. Thus, a first plate about the tube located nearest the particle source, attracts a particle which as it passes through the tube past the first plate is then repelled by the reverse polarity of the second plate of the pair to continue moving towards the target

  18. PLT neutral injection ignitron accelerating supply

    International Nuclear Information System (INIS)

    Ashcroft, D.L.; Murray, J.G.; Newman, R.A.; Peterson, F.L.

    1975-11-01

    A phase-controlled rectifier was designed for the accelerating supply on the PLT Neutral Beam Injection system at PPPL. The rectifier must furnish 70 amperes at up to 50 KV for 300 milliseconds, with a duty cycle of up to 10 percent. Protection of the injectors requires the supply to withstand repeated crowbarring. The rectifying element selected to satisfy these requirements was a commercially-available ignitron, installed in a supporting frame and using firing circuits and controls designed by PPPL

  19. PLT neutral injection ignitron accelerating supply

    International Nuclear Information System (INIS)

    Ashcroft, D.L.; Murray, J.G.; Newman, R.A.; Peterson, F.L.

    1976-03-01

    A phase-controlled rectifier has been designed for the accelerating supply on the PLT Neutral Beam Injection system at PPPL. The rectifier must furnish 70 amperes at up to 50 KV for 300 milliseconds, with a duty cycle of up to 10 percent. Protection of the injectors requires the supply to withstand repeated crowbarring. The rectifying element selected to satisfy these requirements was a commercially-available ignitron, installed in a supporting frame and using firing circuits and controls designed by PPPL

  20. Unified Theoretical Frame of a Joint Transmitter-Receiver Reduced Dimensional STAP Method for an Airborne MIMO Radar

    Directory of Open Access Journals (Sweden)

    Guo Yiduo

    2016-10-01

    Full Text Available The unified theoretical frame of a joint transmitter-receiver reduced dimensional Space-Time Adaptive Processing (STAP method is studied for an airborne Multiple-Input Multiple-Output (MIMO radar. First, based on the transmitted waveform diverse characteristics of the transmitted waveform of the airborne MIMO radar, a uniform theoretical frame structure for the reduced dimensional joint adaptive STAP is constructed. Based on it, three reduced dimensional STAP fixed structures are established. Finally, three reduced rank STAP algorithms, which are suitable for a MIMO system, are presented corresponding to the three reduced dimensional STAP fixed structures. The simulations indicate that the joint adaptive algorithms have preferable clutter suppression and anti-interference performance.

  1. Review of gravitomagnetic acceleration from accretion disks

    Science.gov (United States)

    Poirier, J.; Mathews, G. J.

    2015-11-01

    We review the development of the equations of gravitoelectromagnetism and summarize how the motion of the neutral masses in an accretion disk orbiting a black hole creates a general-relativistic magnetic-like (gravitomagnetic) field that vertically accelerates neutral particles near the accretion disk upward and then inward toward the axis of the accretion disk. Even though this gravitomagnetic field is not the only mechanism to produce collimated jets, it is a novel means to identify one general relativistic effect from a much more complicated problem. In addition, as the accelerated material above or below the accretion disk nears the axis with a nearly vertical direction, a frame-dragging effect twists the trajectories around the axis thus contributing to the collimation of the jet.

  2. New characterizations of fusion frames (frames of subspaces)

    Indian Academy of Sciences (India)

    Theory (College Park, MD, 2003) Contemp. Math. 345, Amer. Math. Soc. (RI: Provi- dence) (2004) 87–113. [4] Casazza P G and Kutyniok G, Robustness of Fusion Frames under Erasures of sub- spaces and of Local Frame Vectors, Radon transforms, geometry, and wavelets (LA: New Orleans) (2006) Contemp. Math., Amer.

  3. Relativity and accelerator engineering

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Schenefeld (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-09-15

    From a geometrical viewpoint, according to the theory of relativity, space and time constitute a four-dimensional continuum with pseudo-Euclidean structure. This has recently begun to be a practically important statement in accelerator physics. An X-ray Free Electron Laser (XFEL) is in fact the best, exciting example of an engineering system where improvements in accelerator technology makes it possible to develop ultrarelativistic macroscopic objects with an internal fine structure, and the theory of relativity plays an essential role in their description. An ultrarelativistic electron bunch modulated at nanometer-scale in XFELs has indeed a macroscopic finite-size of order of 10 μm. Its internal, collective structure is characterized in terms of a wave number vector. Here we will show that a four-dimensional geometrical approach, unusual in accelerator physics, is needed to solve problems involving the emission of radiation from an ultrarelativistic modulated electron beam accelerating along a curved trajectory. We will see that relativistic kinematics enters XFEL physics in a most fundamental way through the so-called Wigner rotation of the modulation wave number vector, which is closely associated to the relativity of simultaneity. If not taken into account, relativistic kinematics effects would lead to a strong qualitative disagreement between theory and experiments. In this paper, several examples of relativistic kinematics effects, which are important for current and future XFEL operation, are studied. The theory of relativity is applied by providing details of the clock synchronization procedure within the laboratory frame. This approach, exploited here but unusual in literature, is rather ''practical'', and should be acceptable to accelerator physicists.

  4. Structure, shape, and evolution of radiatively accelerated QSO emission-line clouds

    International Nuclear Information System (INIS)

    Blumenthal, G.R.; Mathews, W.G.

    1979-01-01

    The possibility that the broad emission-line regions of QSOs and active galactic nuclei are formed by a multitude of small clouds which are radiatively accelerated is discussed. Although this model is by no means certain at present, it has four virtues: (1) Observed emission-line widths can be produced with observationally allowed electron densities, UV luminosities, and ionization levels. (2) The acceleration force is coherent in each cloud are found. (3) Reasonable line profiles can result for all emission lines. (4) Photoionization of hydrogen accounts for both heating and acceleration of the emission-line gas. A self-consistent model is developed for the structure, shape, and evolution of radiatively accelerated clouds. The shape varies with cloud mass, and two distinct types of clouds. Fully ionized clouds of very low mass approach a nearly spherical shape. However, all clouds having masses greater than some critical mass adopt a ''pancake'' shape. The condition for constant cloud mass in the cloud frame is shown to be equivalent to the equation of motion of a cloud in the rest frame of the QSO. The emission-line profiles can be sensitive to radial variations in the properties of the intercloud medium, and those properties that correspond to observed profiles are discussed. Finally, the covering factor of a system of pancake clouds is estimated along with the total number of clouds required--approximately 10 14 clouds in each QSO

  5. Development of uniform hazard response spectra for Kalpakkam, Kaiga and Kudankulam

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Rao, K.S.

    2009-11-01

    Variation of Peak Ground Acceleration (PGA) with mean recurrence interval (MRI) has also been presented using various well-known correlations. The present work develops uniform hazard response spectra i.e. spectra having the same MRI at all frequencies for Kalpakkam, Kaiga and Kudankulam sites. These results determine the seismic hazard at the given site and the associated uncertainties. Typical examples are given to show the sensitivity of the results to changes in various parameters. The results will be useful in evaluation of seismic risk. (author)

  6. Changing climate, changing frames

    International Nuclear Information System (INIS)

    Vink, Martinus J.; Boezeman, Daan; Dewulf, Art; Termeer, Catrien J.A.M.

    2013-01-01

    Highlights: ► We show development of flood policy frames in context of climate change attention. ► Rising attention on climate change influences traditional flood policy framing. ► The new framing employs global-scale scientific climate change knowledge. ► With declining attention, framing disregards climate change, using local knowledge. ► We conclude that frames function as sensemaking devices selectively using knowledge. -- Abstract: Water management and particularly flood defence have a long history of collective action in low-lying countries like the Netherlands. The uncertain but potentially severe impacts of the recent climate change issue (e.g. sea level rise, extreme river discharges, salinisation) amplify the wicked and controversial character of flood safety policy issues. Policy proposals in this area generally involve drastic infrastructural works and long-term investments. They face the difficult challenge of framing problems and solutions in a publicly acceptable manner in ever changing circumstances. In this paper, we analyse and compare (1) how three key policy proposals publicly frame the flood safety issue, (2) the knowledge referred to in the framing and (3) how these frames are rhetorically connected or disconnected as statements in a long-term conversation. We find that (1) framings of policy proposals differ in the way they depict the importance of climate change, the relevant timeframe and the appropriate governance mode; (2) knowledge is selectively mobilised to underpin the different frames and (3) the frames about these proposals position themselves against the background of the previous proposals through rhetorical connections and disconnections. Finally, we discuss how this analysis hints at the importance of processes of powering and puzzling that lead to particular framings towards the public at different historical junctures

  7. Framing Gangnam Style

    Directory of Open Access Journals (Sweden)

    Hyunsun Catherine Yoon

    2017-08-01

    Full Text Available This paper examines the way in which news about Gangnam Style was framed in the Korean press. First released on 15th July 2012, it became the first video to pass two billion views on YouTube. 400 news articles between July 2012 and March 2013 from two South Korean newspapers - Chosun Ilbo and Hankyoreh were analyzed using the frame analysis method in five categories: industry/economy, globalization, cultural interest, criticism, and competition. The right-left opinion cleavage is important because news frames interact with official discourses, audience frames and prior knowledge which consequently mediate effects on public opinion, policy debates, social movement and individual interpretations. Whilst the existing literature on Gangnam Style took rather holistic approach, this study aimed to fill the lacuna, considering this phenomenon as a dynamic process, by segmenting different stages - recognition, spread, peak and continuation. Both newspapers acknowledged Gangnam Style was an epochal event but their perspectives and news frames were different; globalization frame was most frequently used in Chosun Ilbo whereas cultural interest frame was most often used in Hankyoreh. Although more critical approaches were found in Hankyoreh, reflecting the right-left opinion cleavage, both papers lacked in critical appraisal and analysis of Gangnam Style’s reception in a broader context of the new Korean Wave.

  8. The mass-damped Riemann problem and the aerodynamic surface force calculation for an accelerating body

    International Nuclear Information System (INIS)

    Tan, Zhiqiang; Wilson, D.; Varghese, P.L.

    1997-01-01

    We consider an extension of the ordinary Riemann problem and present an efficient approximate solution that can be used to improve the calculations of aerodynamic forces on an accelerating body. The method is demonstrated with one-dimensional examples where the Euler equations and the body motion are solved in the non-inertial co-ordinate frame fixed to the accelerating body. 8 refs., 6 figs

  9. The effect of blood acceleration on the ultrasound power Doppler spectrum

    Science.gov (United States)

    Matchenko, O. S.; Barannik, E. A.

    2017-09-01

    The purpose of the present work was to study the influence of blood acceleration and time window length on the power Doppler spectrum for Gaussian ultrasound beams. The work has been carried out on the basis of continuum model of the ultrasound scattering from inhomogeneities in fluid flow. Correlation function of fluctuations has been considered for uniformly accelerated scatterers, and the resulting power Doppler spectra have been calculated. It is shown that within the initial phase of systole uniformly accelerated slow blood flow in pulmonary artery and aorta tends to make the correlation function about 4.89 and 7.83 times wider, respectively, than the sensitivity function of typical probing system. Given peak flow velocities, the sensitivity function becomes, vice versa, about 4.34 and 3.84 times wider, respectively, then the correlation function. In these limiting cases, the resulting spectra can be considered as Gaussian. The optimal time window duration decreases with increasing acceleration of blood flow and equals to 11.62 and 7.54 ms for pulmonary artery and aorta, respectively. The width of the resulting power Doppler spectrum is shown to be defined mostly by the wave vector of the incident field, the duration of signal and the acceleration of scatterers in the case of low flow velocities. In the opposite case geometrical properties of probing field and the average velocity itself are more essential. In the sense of signal-noise ratio, the optimal duration of time window can be found. Abovementioned results may contribute to the improved techniques of Doppler ultrasound diagnostics of cardiovascular system.

  10. Planned studies of charge collection in non-uniformly irradiated Si and GaAs detectors

    International Nuclear Information System (INIS)

    Rosenfeld, A.; Reinhard, M.; Carolan, M.; Kaplan, G.; Lerch, M.; Alexiev, D.

    1995-01-01

    The aim of this project is to study the time and amplitude characteristics of silicon ion-implanted detectors non-uniformly irradiated with fast neutrons in order to predict their radiation behaviour in the LHC and space. It is expected in such detectors increases of the charge deficit due to trapping by large scale traps and transient time increases due to the reduction of the mobility. The theoretical model will be modified to describe the charge kinetics in the electrical field of the detector created by a non uniform space charge distribution. Experimental confirmation techniques are needed to develop non uniform predictable damage of silicon detectors using fast neutron sources (accelerators, reactors) and to study peculiarities of the charge transport in different parts of the detector. In parallel to experimental research will be started the theoretical development of the charge transport model for non-uniform distribution of space charge in the depletion layer (Neff). The model will include the linear distribution of Neff(y) along the detector as well as the change of sign of Neff (conversion from n to p type of silicon) inside the detector

  11. Case Study of Local Damage Indicators for a 2-Bay, 6-Storey RC-Frame subject to Earthquakes

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    1997-01-01

    A simulation study of a 2-bay, 6storey model test RC-frame(scale 1:5) subject to earthquakes is considered in this paper. Based on measured (simulated) storey accelerations and ground surface accelerations several indices for the storey damage, including interstorey drift, flexural damage ratios......, normalized cumulative dissipated energy, Park and Ang's indicator, a low-cycle fatigue damage index and a recently proposed local softening damage index estimated from time-varying eigenfrequencies are used to evaluate the damage state of the structure after the earthquake. Storey displacements are obtained...

  12. Case Study of Local Damage Indicators for a 2-Bay, 6-Storey RC-Frame subject to Earthquakes

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    A simulation study of a 2-bay, 6storey model test RC-frame(scale 1:5) subject to earthquakes is considered in this paper. Based on measured (simulated) storey accelerations and ground surface accelerations several indices for the storey damage, including interstorey drift, flexural damage ratios......, normalized cumulative dissipated energy, Park and Ang's indicator, a low-cycle fatigue damage index and a recently proposed local softening damage index estimated from time-varying eigenfrequencies are used to evaluate the damage state of the structure after the earthquake. Storey displacements are obtained...

  13. Performance Based Plastic Design of Concentrically Braced Frame attuned with Indian Standard code and its Seismic Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Sejal Purvang Dalal

    2015-12-01

    Full Text Available In the Performance Based Plastic design method, the failure is predetermined; making it famous throughout the world. But due to lack of proper guidelines and simple stepwise methodology, it is not quite popular in India. In this paper, stepwise design procedure of Performance Based Plastic Design of Concentrically Braced frame attuned with the Indian Standard code has been presented. The comparative seismic performance evaluation of a six storey concentrically braced frame designed using the displacement based Performance Based Plastic Design (PBPD method and currently used force based Limit State Design (LSD method has also been carried out by nonlinear static pushover analysis and time history analysis under three different ground motions. Results show that Performance Based Plastic Design method is superior to the current design in terms of displacement and acceleration response. Also total collapse of the frame is prevented in the PBPD frame.

  14. Frames for undergraduates

    CERN Document Server

    Han, Deguang; Larson, David; Weber, Eric

    2007-01-01

    Frames for Undergraduates is an undergraduate-level introduction to the theory of frames in a Hilbert space. This book can serve as a text for a special-topics course in frame theory, but it could also be used to teach a second semester of linear algebra, using frames as an application of the theoretical concepts. It can also provide a complete and helpful resource for students doing undergraduate research projects using frames. The early chapters contain the topics from linear algebra that students need to know in order to read the rest of the book. The later chapters are devoted to advanced topics, which allow students with more experience to study more intricate types of frames. Toward that end, a Student Presentation section gives detailed proofs of fairly technical results with the intention that a student could work out these proofs independently and prepare a presentation to a class or research group. The authors have also presented some stories in the Anecdotes section about how this material has moti...

  15. Changing quantum reference frames

    OpenAIRE

    Palmer, Matthew C.; Girelli, Florian; Bartlett, Stephen D.

    2013-01-01

    We consider the process of changing reference frames in the case where the reference frames are quantum systems. We find that, as part of this process, decoherence is necessarily induced on any quantum system described relative to these frames. We explore this process with examples involving reference frames for phase and orientation. Quantifying the effect of changing quantum reference frames serves as a first step in developing a relativity principle for theories in which all objects includ...

  16. On Framing

    DEFF Research Database (Denmark)

    Peder Pedersen, Claus

    2018-01-01

    On framing as artistic and conceptual tool in the works of Claudia Carbone. Contribution to exhibition at the Aarhus School of Architecture.......On framing as artistic and conceptual tool in the works of Claudia Carbone. Contribution to exhibition at the Aarhus School of Architecture....

  17. Temperature distribution in a uniformly moving medium

    International Nuclear Information System (INIS)

    Mitchell, Joseph D; Petrov, Nikola P

    2009-01-01

    We apply several physical ideas to determine the steady temperature distribution in a medium moving with uniform velocity between two infinite parallel plates. We compute it in the coordinate frame moving with the medium by integration over the 'past' to account for the influence of an infinite set of instantaneous point sources of heat in past moments as seen by an observer moving with the medium. The boundary heat flux is simulated by appropriately distributed point heat sources on the inner side of an adiabatically insulating boundary. We make an extensive use of the Green functions with an emphasis on their physical meaning. The methodology used in this paper is of great pedagogical value as it offers an opportunity for students to see the connection between powerful mathematical techniques and their physical interpretation in an intuitively clear physical problem. We suggest several problems and a challenging project that can be easily incorporated in undergraduate or graduate courses

  18. Effect of high frequency content of uniform hazard response spectra on nuclear power plant structures, systems and components

    Energy Technology Data Exchange (ETDEWEB)

    Usmani, A. [Amec Foster Wheeler, Toronto, ON (Canada); Baughman, P.D. [Paul D. Baughman Consulting, Exeter, NH (United States)

    2015-07-01

    The Uniform Hazard Spectrum (UHS) is developed from a probabilistic seismic hazard assessment and represents a response spectrum for which the amplitude at each frequency has a specified and uniform (equal) probability of exceedance. The high spectral acceleration at high frequencies in the UHS can result mainly from small non-damaging low energy earthquakes. Historically Canadian and U.S. nuclear power plants have been designed using the standard shape spectrum given in CSA N289.3 or USNRC Regulatory Guide 1.60, which have maximum spectral accelerations in the lower (2-10 Hz.) frequency range. The impact of the high frequency content of UHS on the nuclear power plant SSCs is required to be assessed. This paper briefly describes the methodologies used for screening and evaluation of the effects of UHS high frequency content on the nuclear power SSCs that have been designed using the CSA N289.3 standard shape spectrum. (author)

  19. Improvements of the beam timing structure during a slow extraction from the 70 GeV IFVE accelerator

    International Nuclear Information System (INIS)

    Vorob'ev, V.K.; Levin, A.V.; Mojzhes, L.L.; Myznikov, K.P.; Tatarenko, V.M.; Fedotov, Yu.S.

    1977-01-01

    To improve the density uniformity of an extracted beam in the slow extraction system of the IFVE accelerator a correlation analysis of a timing structure of a proton beam is developed. A passive filter for a power supply system of an annular electromagnet is reconstructed by introduction of a double-loop circuit to reduce pulsations of 600 Hz main frequency and higher harmonics. To suppress accelerator field pulsations of subharmonic components from 50 to 300 Hz an active filter was introduced, where high Q qualities band filters were inserted. Using the above methods of pulsation suppression permits to improve the density uniformity of the extracted beam

  20. Gain uniformity, linearity, saturation and depletion in gated microchannel-plate x-ray framing cameras

    International Nuclear Information System (INIS)

    Landen, O.L.; Bell, P.M.; Satariano, J.J.; Oertel, J.A.; Bradley, D.K.

    1994-01-01

    The pulsed characteristics of gated, stripline configuration microchannel-plate (MCP) detectors used in X-ray framing cameras deployed on laser plasma experiments worldwide are examined in greater detail. The detectors are calibrated using short (20 ps) and long (500 ps) pulse X-ray irradiation and 3--60 ps, deep UV (202 and 213 nm), spatially-smoothed laser irradiation. Two-dimensional unsaturated gain profiles show 5 in irradiation and fitted using a discrete dynode model. Finally, a pump-probe experiment quantifying for the first time long-suspected gain depletion by strong localized irradiation was performed. The mechanism for the extra voltage and hence gain degradation is shown to be associated with intense MCP irradiation in the presence of the voltage pulse, at a fluence at least an order of magnitude above that necessary for saturation. Results obtained for both constant pump area and constant pump fluence are presented. The data are well modeled by calculating the instantaneous electrical energy loss due to the intense charge extraction at the pump site and then recalculating the gain downstream at the probe site given the pump-dependent degradation in voltage amplitude

  1. SEISMIC FRAGILITY ANALYSIS OF IMPROVED RC FRAMES USING DIFFERENT TYPES OF BRACING

    Directory of Open Access Journals (Sweden)

    HAMED HAMIDI JAMNANI

    2017-04-01

    Full Text Available Application of bracings to increase the lateral stiffness of building structures is a technique of seismic improvement that engineers frequently have recourse to. Accordingly, investigating the role of bracings in concrete structures along with the development of seismic fragility curves are of overriding concern to civil engineers. In this research, an ordinary RC building, designed according to the 1st edition of Iranian seismic code, was selected for examination. According to FEMA 356 code, this building is considered to be vulnerable. To improve the seismic performance of this building, 3 different types of bracings, which are Concentrically Braced Frames, Eccentrically Braced Frames and Buckling Restrained Frames were employed, and each bracing element was distributed in 3 different locations in the building. The researchers developed fragility curves and utilized 30 earthquake records on the Peak Ground Acceleration seismic intensity scale to carry out a time history analysis. Tow damage scale, including Inter-Story Drifts and Plastic Axial Deformation were also used. The numerical results obtained from this investigation confirm that Plastic Axial Deformation is more reliable than conventional approaches in developing fragility curves for retrofitted frames. In lieu of what is proposed, the researchers selected the suitable damage scale and developed and compared log-normal distribution of fragility curves first for the original and then for the retrofitted building.

  2. Study on comparison of special moment frame steel structure (SMF) and base isolation special moment frame steel structure (BI-SMF) in Indonesia

    Science.gov (United States)

    Setiawan, Jody; Nakazawa, Shoji

    2017-10-01

    This paper discusses about comparison of seismic response behaviors, seismic performance and seismic loss function of a conventional special moment frame steel structure (SMF) and a special moment frame steel structure with base isolation (BI-SMF). The validation of the proposed simplified estimation method of the maximum deformation of the base isolation system by using the equivalent linearization method and the validation of the design shear force of the superstructure are investigated from results of the nonlinear dynamic response analysis. In recent years, the constructions of steel office buildings with seismic isolation system are proceeding even in Indonesia where the risk of earthquakes is high. Although the design code for the seismic isolation structure has been proposed, there is no actual construction example for special moment frame steel structure with base isolation. Therefore, in this research, the SMF and BI-SMF buildings are designed by Indonesian Building Code which are assumed to be built at Padang City in Indonesia. The material of base isolation system is high damping rubber bearing. Dynamic eigenvalue analysis and nonlinear dynamic response analysis are carried out to show the dynamic characteristics and seismic performance. In addition, the seismic loss function is obtained from damage state probability and repair cost. For the response analysis, simulated ground accelerations, which have the phases of recorded seismic waves (El Centro NS, El Centro EW, Kobe NS and Kobe EW), adapted to the response spectrum prescribed by the Indonesian design code, that has, are used.

  3. Phase transitions in local equation-of-state approximation and anomalies of spatial charge profiles in non-uniform plasma

    Science.gov (United States)

    Chigvintsev, A. Yu; Zorina, I. G.; Noginova, L. Yu; Iosilevskiy, I. L.

    2018-01-01

    Impressive appearance of discontinuities in equilibrium spatial charge profiles in non-uniform Coulomb systems is under discussions in wide number of thermoelectrostatics problems. Such discontinuities are considered as peculiar micro-level manifestation of phase transitions and intrinsic macro-level non-ideality effects in local equation of state (EOS), which should be used for description of non-ideal ionic subsystem in frames of local-density (or “pseudofluid”, or “jellium” etc) approximation. Such discontinuities were discussed already by the authors for electronic subsystems. Special emphasis is made in present paper on the mentioned above non-ideality effects in non-uniform ionic subsystems, such as micro-ions profile within screening “cloud” around macro-ion in complex (dusty, colloid etc) plasmas, equilibrium charge profile in ionic traps or (and) in the neighborhood vicinity of “charged wall” etc). Multiphase EOS for simplified ionic model of classical charged hard spheres on uniformly compressible electrostatic compensating background was constructed and several illustrative examples of discussed discontinuous ionic profiles were calculated.

  4. Frame by Frame II: A Filmography of the African American Image, 1978-1994.

    Science.gov (United States)

    Klotman, Phyllis R.; Gibson, Gloria J.

    A reference guide on African American film professionals, this book is a companion volume to the earlier "Frame by Frame I." It focuses on giving credit to African Americans who have contributed their talents to a film industry that has scarcely recognized their contributions, building on the aforementioned "Frame by Frame I,"…

  5. Impact of quasar proper motions on the alignment between the International Celestial Reference Frame and the Gaia reference frame

    Science.gov (United States)

    Liu, J.-C.; Malkin, Z.; Zhu, Z.

    2018-03-01

    The International Celestial Reference Frame (ICRF) is currently realized by the very long baseline interferometry (VLBI) observations of extragalactic sources with the zero proper motion assumption, while Gaia will observe proper motions of these distant and faint objects to an accuracy of tens of microarcseconds per year. This paper investigates the difference between VLBI and Gaia quasar proper motions and it aims to understand the impact of quasar proper motions on the alignment of the ICRF and Gaia reference frame. We use the latest time series data of source coordinates from the International VLBI Service analysis centres operated at Goddard Space Flight Center (GSF2017) and Paris observatory (OPA2017), as well as the Gaia auxiliary quasar solution containing 2191 high-probability optical counterparts of the ICRF2 sources. The linear proper motions in right ascension and declination of VLBI sources are derived by least-squares fits while the proper motions for Gaia sources are simulated taking into account the acceleration of the Solar system barycentre and realistic uncertainties depending on the source brightness. The individual and global features of source proper motions in GSF2017 and OPA2017 VLBI data are found to be inconsistent, which may result from differences in VLBI observations, data reduction and analysis. A comparison of the VLBI and Gaia proper motions shows that the accuracies of the components of rotation and glide between the two systems are 2-4 μas yr- 1 based on about 600 common sources. For the future alignment of the ICRF and Gaia reference frames at different wavelengths, the proper motions of quasars must necessarily be considered.

  6. Framing theory

    NARCIS (Netherlands)

    de Vreese, C.H.; Lecheler, S.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.

    2016-01-01

    Political issues can be viewed from different perspectives and they can be defined differently in the news media by emphasizing some aspects and leaving others aside. This is at the core of news framing theory. Framing originates within sociology and psychology and has become one of the most used

  7. Framing politics

    NARCIS (Netherlands)

    Lecheler, S.K.

    2010-01-01

    This dissertation supplies a number of research findings that add to a theory of news framing effects, and also to the understanding of the role media effects play in political communication. We show that researchers must think more about what actually constitutes a framing effect, and that a

  8. Balanced sparse model for tight frames in compressed sensing magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Yunsong Liu

    Full Text Available Compressed sensing has shown to be promising to accelerate magnetic resonance imaging. In this new technology, magnetic resonance images are usually reconstructed by enforcing its sparsity in sparse image reconstruction models, including both synthesis and analysis models. The synthesis model assumes that an image is a sparse combination of atom signals while the analysis model assumes that an image is sparse after the application of an analysis operator. Balanced model is a new sparse model that bridges analysis and synthesis models by introducing a penalty term on the distance of frame coefficients to the range of the analysis operator. In this paper, we study the performance of the balanced model in tight frame based compressed sensing magnetic resonance imaging and propose a new efficient numerical algorithm to solve the optimization problem. By tuning the balancing parameter, the new model achieves solutions of three models. It is found that the balanced model has a comparable performance with the analysis model. Besides, both of them achieve better results than the synthesis model no matter what value the balancing parameter is. Experiment shows that our proposed numerical algorithm constrained split augmented Lagrangian shrinkage algorithm for balanced model (C-SALSA-B converges faster than previously proposed algorithms accelerated proximal algorithm (APG and alternating directional method of multipliers for balanced model (ADMM-B.

  9. Serialising languages: Satellite-framed, verb-framed or neither ...

    African Journals Online (AJOL)

    The diversity in the coding of the core schema of motion, i.e., Path, has led to a traditional typology of languages into verb-framed and satellite-framed languages. In the former Path is encoded in verbs and in the latter it is encoded in non-verb elements that function as sisters to co-event expressing verbs such as manner ...

  10. Direct drive acceleration of planar targets with the Nike KrF laser

    International Nuclear Information System (INIS)

    Pawley, C.J.; Sethian, J.D.; Bodner, S.E.

    1999-01-01

    Nike is a multi-kilojoule KrF laser with very high beam uniformity (ΔI/I<0.2% with all 36 overlapped beams), and the capability to accelerate relatively thick targets on a low adiabat under conditions scalable to direct drive ICF. In a first set of experiments we determined the effect of the imprinting by varying the uniformity of the foot of the laser pulse and measuring the growth of the subsequent Rayleigh-Taylor instability. We found that the lower the imprint, the longer the mass modulations take to reach a given level. This is in quantitative agreement with our 2-D hydrodynamics simulations. The results are promising for direct drive with a very uniform laser. (orig.)

  11. Ultra-Accelerated Natural Sunlight Exposure Testing Facilities

    Science.gov (United States)

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2004-11-23

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in a chamber that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  12. Simulation of density measurements in plasma wakefields using photo acceleration

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Sadler, James; Burrows, Philip N; Trines, Raoul; Holloway, James; Wing, Matthew; Bingham, Robert; Norreys, Peter

    2015-01-01

    One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  13. Sparse Matrices in Frame Theory

    DEFF Research Database (Denmark)

    Lemvig, Jakob; Krahmer, Felix; Kutyniok, Gitta

    2014-01-01

    Frame theory is closely intertwined with signal processing through a canon of methodologies for the analysis of signals using (redundant) linear measurements. The canonical dual frame associated with a frame provides a means for reconstruction by a least squares approach, but other dual frames...... yield alternative reconstruction procedures. The novel paradigm of sparsity has recently entered the area of frame theory in various ways. Of those different sparsity perspectives, we will focus on the situations where frames and (not necessarily canonical) dual frames can be written as sparse matrices...

  14. Summary talk - status of accelerator neutrino physics

    International Nuclear Information System (INIS)

    Lee, B.W.

    1977-01-01

    I shall address theoretical questions that are immediately relevant to today's accelerator neutrino physics. The frame of reference I shall dwell in is quantum chromodynamics, in which quarks are assumed to carry both flavors and colors, and confining forces among quarks are transmitted by color gluons. The physical hadrons are color-neutral. Quarks presumably cannot be isolated at least at the present accelerator energies. For most phenomenological considerations, whether confinement is permanent or temporary does not really matter, but I insist that quarks behave as if they were free at short distances, and a color symmetry is exact. Inasmuch as quark cannot exist in an isolated state, what one means by a quark mass is a matter of definition. One definition might be superior to others in a given context. (orig.) [de

  15. Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature

    OpenAIRE

    Soichiro Tsujino; Takashi Tomizaki

    2016-01-01

    Increasing the data acquisition rate of X-ray diffraction images for macromolecular crystals at room temperature at synchrotrons has the potential to significantly accelerate both structural analysis of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein crystals in liquid droplets. The rapid spinn...

  16. When message-frame fits salient cultural-frame, messages feel more persuasive.

    Science.gov (United States)

    Uskul, Ayse K; Oyserman, Daphna

    2010-03-01

    The present study examines the persuasive effects of tailored health messages comparing those tailored to match (versus not match) both chronic cultural frame and momentarily salient cultural frame. Evidence from two studies (Study 1: n = 72 European Americans; Study 2: n = 48 Asian Americans) supports the hypothesis that message persuasiveness increases when chronic cultural frame, health message tailoring and momentarily salient cultural frame all match. The hypothesis was tested using a message about health risks of caffeine consumption among individuals prescreened to be regular caffeine consumers. After being primed for individualism, European Americans who read a health message that focused on the personal self were more likely to accept the message-they found it more persuasive, believed they were more at risk and engaged in more message-congruent behaviour. These effects were also found among Asian Americans who were primed for collectivism and who read a health message that focused on relational obligations. The findings point to the importance of investigating the role of situational cues in persuasive effects of health messages and suggest that matching content to primed frame consistent with the chronic frame may be a way to know what to match messages to.

  17. Impact of Uniform Methods on Interlaboratory Antibody Titration Variability: Antibody Titration and Uniform Methods.

    Science.gov (United States)

    Bachegowda, Lohith S; Cheng, Yan H; Long, Thomas; Shaz, Beth H

    2017-01-01

    -Substantial variability between different antibody titration methods prompted development and introduction of uniform methods in 2008. -To determine whether uniform methods consistently decrease interlaboratory variation in proficiency testing. -Proficiency testing data for antibody titration between 2009 and 2013 were obtained from the College of American Pathologists. Each laboratory was supplied plasma and red cells to determine anti-A and anti-D antibody titers by their standard method: gel or tube by uniform or other methods at different testing phases (immediate spin and/or room temperature [anti-A], and/or anti-human globulin [AHG: anti-A and anti-D]) with different additives. Interlaboratory variations were compared by analyzing the distribution of titer results by method and phase. -A median of 574 and 1100 responses were reported for anti-A and anti-D antibody titers, respectively, during a 5-year period. The 3 most frequent (median) methods performed for anti-A antibody were uniform tube room temperature (147.5; range, 119-159), uniform tube AHG (143.5; range, 134-150), and other tube AHG (97; range, 82-116); for anti-D antibody, the methods were other tube (451; range, 431-465), uniform tube (404; range, 382-462), and uniform gel (137; range, 121-153). Of the larger reported methods, uniform gel AHG phase for anti-A and anti-D antibodies had the most participants with the same result (mode). For anti-A antibody, 0 of 8 (uniform versus other tube room temperature) and 1 of 8 (uniform versus other tube AHG), and for anti-D antibody, 0 of 8 (uniform versus other tube) and 0 of 8 (uniform versus other gel) proficiency tests showed significant titer variability reduction. -Uniform methods harmonize laboratory techniques but rarely reduce interlaboratory titer variance in comparison with other methods.

  18. Advances of dense plasma physics with particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, D.H.H.; Blazevic, A.; Rosmej, O.N.; Spiller, P.; Tahir, N.A.; Weyrich, K. [Gesellschaft fur Schwerionenforschung, GSI-Darmstadt, Plasmaphysik, Darmstadt (Germany); Hoffmann, D.H.H.; Dafni, T.; Kuster, M.; Roth, M.; Udrea, S.; Varentsov, D. [DarmstadtTechnische Univ., Institut fur Kernphysik (Germany); Jacoby, J. [Frankfurt Univ., Institut fur Angewandte Physik (Germany); Zioutas, K. [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Patras Univ., Dept. of Physics (Greece); Sharkov, B.Y. [Institut for Theoretical and Experimental Physics ITEP, Moscow (Russian Federation)

    2006-06-15

    High intensity particle beams from accelerators induce high energy density states in bulk matter. The SIS-18 heavy ion synchrotron at GSI (Darmstadt, Germany) now routinely delivers intense Uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Due to the specific nature of the ion-matter interaction a volume of matter is heated uniformly with low gradients of temperature and pressure in the initial phase, depending on the pulse structure of the beam with respect to space and time. The new accelerator complex FAIR (Facility for Antiproton and ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. One special piece of accelerator equipment a superconducting high field dipole magnet, developed for the LHC at CERN is now serving as a key instrument to diagnose the dense plasma of the sun interior plasma, thus providing an extremely interesting combination of accelerator physics, plasma physics and particle physics. (authors)

  19. Advances of dense plasma physics with particle accelerators

    International Nuclear Information System (INIS)

    Hoffmann, D.H.H.; Blazevic, A.; Rosmej, O.N.; Spiller, P.; Tahir, N.A.; Weyrich, K.; Hoffmann, D.H.H.; Dafni, T.; Kuster, M.; Roth, M.; Udrea, S.; Varentsov, D.; Jacoby, J.; Zioutas, K.; Sharkov, B.Y.

    2006-01-01

    High intensity particle beams from accelerators induce high energy density states in bulk matter. The SIS-18 heavy ion synchrotron at GSI (Darmstadt, Germany) now routinely delivers intense Uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Due to the specific nature of the ion-matter interaction a volume of matter is heated uniformly with low gradients of temperature and pressure in the initial phase, depending on the pulse structure of the beam with respect to space and time. The new accelerator complex FAIR (Facility for Antiproton and ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. One special piece of accelerator equipment a superconducting high field dipole magnet, developed for the LHC at CERN is now serving as a key instrument to diagnose the dense plasma of the sun interior plasma, thus providing an extremely interesting combination of accelerator physics, plasma physics and particle physics. (authors)

  20. Quantum ring in a rotating frame in the presence of a topological defect

    International Nuclear Information System (INIS)

    Dantas, L.; Furtado, C.; Silva Netto, A.L.

    2015-01-01

    In this contribution, we study the effects caused by rotation of an electron/hole in the presence of a screw dislocation confined in a quantum ring potential, within a quantum dynamics. The Tan–Inkson potential is used to model the confinement of the particle in two-dimensional quantum ring. We suppose that the quantum ring is placed in the presence of an external uniform magnetic field and an Aharonov–Bohm flux in the center of the system, and that the frame rotates around the z-axis. The Schrödinger equation is solved and the eigenfunctions and energy eigenvalues are exactly obtained for this configuration. The influence of the dislocation and the rotation on both the persistent current and magnetization is also studied. - Highlights: • Quantum ring in a rotating frame. • Tan–Inkson potential in the presence of rotation. • Quantum ring in the presence of screw dislocation. • Landau levels

  1. Experimental Studies on Damage Detection in Frame Structures Using Vibration Measurements

    Directory of Open Access Journals (Sweden)

    Giancarlo Fraraccio

    2010-01-01

    Full Text Available This paper presents an experimental study of frequency and time domain identification algorithms and discusses their effectiveness in structural health monitoring of frame structures using acceleration input and response data. Three algorithms were considered: 1 a frequency domain decomposition algorithm (FDD, 2 a time domain Observer Kalman IDentification algorithm (OKID, and 3 a subsequent physical parameter identification algorithm (MLK. Through experimental testing of a four-story steel frame model on a uniaxial shake table, the inherent complications of physical instrumentation and testing are explored. Primarily, this study aims to provide a dependable first-order and second-order identification of said test structure in a fully instrumented state. Once the characteristics (i.e. the stiffness matrix for a benchmark structure have been determined, structural damage can be detected by a change in the identified structural stiffness matrix. This work also analyzes the stability of the identified structural stiffness matrix with respect to fluctuations of input excitation magnitude and frequency content in an experimental setting.

  2. Relativistic effects in local inertial frames including parametrized-post-Newtonian effects

    International Nuclear Information System (INIS)

    Shahid-Saless, B.; Ashby, N.

    1988-01-01

    We use the concept of a generalized Fermi frame to describe relativistic effects, due to local and distant sources of gravitation, on a body placed in a local inertial frame of reference. In particular we have considered a model of two spherically symmetric gravitating point sources, moving in circular orbits around a common barycenter where one of the bodies is chosen to be the local and the other the distant one. This has been done using the slow-motion, weak-field approximation and including four of the parametrized-post-Newtonian (PPN) parameters. The position of the classical center of mass must be modified when the PPN parameter zeta 2 is included. We show that the main relativistic effect on a local satellite is described by the Schwarzschild field of the local body and the nonlinear term corresponding to the self-interaction of the local source with itself. There are also much smaller terms that are proportional, respectively, to the product of the potentials of local and distant bodies and to the distant body's self-interactions. The spatial axes of the local frame undergo geodetic precession. In addition we have an acceleration of the order of 10/sup -11/ cm sec -2 that vanish in the case of general relativity, which is discussed in detail

  3. Einstein and Jordan frames reconciled: A frame-invariant approach to scalar-tensor cosmology

    International Nuclear Information System (INIS)

    Catena, Riccardo; Pietroni, Massimo; Scarabello, Luca

    2007-01-01

    Scalar-tensor theories of gravity can be formulated in different frames, most notably, the Einstein and the Jordan one. While some debate still persists in the literature on the physical status of the different frames, a frame transformation in scalar-tensor theories amounts to a local redefinition of the metric, and then should not affect physical results. We analyze the issue in a cosmological context. In particular, we define all the relevant observables (redshift, distances, cross sections, ...) in terms of frame-independent quantities. Then, we give a frame-independent formulation of the Boltzmann equation, and outline its use in relevant examples such as particle freeze-out and the evolution of the cosmic microwave background photon distribution function. Finally, we derive the gravitational equations for the frame-independent quantities at first order in perturbation theory. From a practical point of view, the present approach allows the simultaneous implementation of the good aspects of the two frames in a clear and straightforward way

  4. column frame for design of reinforced concrete sway frames

    African Journals Online (AJOL)

    adminstrator

    design of slender reinforced concrete columns in sway frames according .... concrete,. Ac = gross cross-sectional area of the columns. Step 3: Effective Buckling Length Factors. The effective buckling length factors of columns in a sway frame shall be computed by .... shall have adequate resistance to failure in a sway mode ...

  5. Improved quality of intrafraction kilovoltage images by triggered readout of unexposed frames

    International Nuclear Information System (INIS)

    Poulsen, Per Rugaard; Jonassen, Johnny; Jensen, Carsten; Schmidt, Mai Lykkegaard

    2015-01-01

    Purpose: The gantry-mounted kilovoltage (kV) imager of modern linear accelerators can be used for real-time tumor localization during radiation treatment delivery. However, the kV image quality often suffers from cross-scatter from the megavoltage (MV) treatment beam. This study investigates readout of unexposed kV frames as a means to improve the kV image quality in a series of experiments and a theoretical model of the observed image quality improvements. Methods: A series of fluoroscopic images were acquired of a solid water phantom with an embedded gold marker and an air cavity with and without simultaneous radiation of the phantom with a 6 MV beam delivered perpendicular to the kV beam with 300 and 600 monitor units per minute (MU/min). An in-house built device triggered readout of zero, one, or multiple unexposed frames between the kV exposures. The unexposed frames contained part of the MV scatter, consequently reducing the amount of MV scatter accumulated in the exposed frames. The image quality with and without unexposed frame readout was quantified as the contrast-to-noise ratio (CNR) of the gold marker and air cavity for a range of imaging frequencies from 1 to 15 Hz. To gain more insight into the observed CNR changes, the image lag of the kV imager was measured and used as input in a simple model that describes the CNR with unexposed frame readout in terms of the contrast, kV noise, and MV noise measured without readout of unexposed frames. Results: Without readout of unexposed kV frames, the quality of intratreatment kV images decreased dramatically with reduced kV frequencies due to MV scatter. The gold marker was only visible for imaging frequencies ≥3 Hz at 300 MU/min and ≥5 Hz for 600 MU/min. Visibility of the air cavity required even higher imaging frequencies. Readout of multiple unexposed frames ensured visibility of both structures at all imaging frequencies and a CNR that was independent of the kV frame rate. The image lag was 12.2%, 2

  6. Hall effects on MHD flow past an accelerated plate

    International Nuclear Information System (INIS)

    Soundalgekar, V.M.; Ravi, S.; Hiremath, S.B.

    1980-01-01

    An exact solution of the MHD flow of an incompressible, electrically conducting, viscous fluid past a uniformly accelerated plate is presented. The velocity profiles are shown graphically and the numerical values of axial and transverse components of skin friction are tabulated. At high values of the Hall parameter, ωtau, the velocity is found to be oscillatory near the plate. (author)

  7. Weaving Hilbert space fusion frames

    OpenAIRE

    Neyshaburi, Fahimeh Arabyani; Arefijamaal, Ali Akbar

    2018-01-01

    A new notion in frame theory, so called weaving frames has been recently introduced to deal with some problems in signal processing and wireless sensor networks. Also, fusion frames are an important extension of frames, used in many areas especially for wireless sensor networks. In this paper, we survey the notion of weaving Hilbert space fusion frames. This concept can be had potential applications in wireless sensor networks which require distributed processing using different fusion frames...

  8. Development of uniform hazard response spectra for Tarapur, Trombay and Kakrapar sites

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Rao, K.S.; Kushwaha, H.S.

    2003-08-01

    Traditionally, the seismic design basis ground motion has been specified by normalised response spectral shapes and peak ground acceleration (PGA). The mean recurrence interval (MRI) used to be computed for PGA only. The present work develops uniform hazard response spectra i.e. spectra having the same MRI at all frequencies for Tarapur, Trombay and Kakrapar sites. These results determine the seismic hazard at the given site and the associated uncertainties. Typical examples are given to show the sensitivity of the results to changes in various parameters. (author)

  9. Wavelet frames and their duals

    DEFF Research Database (Denmark)

    Lemvig, Jakob

    2008-01-01

    frames with good time localization and other attractive properties. Furthermore, the dual wavelet frames are constructed in such a way that we are guaranteed that both frames will have the same desirable features. The construction procedure works for any real, expansive dilation. A quasi-affine system....... The signals are then represented by linear combinations of the building blocks with coefficients found by an associated frame, called a dual frame. A wavelet frame is a frame where the building blocks are stretched (dilated) and translated versions of a single function; such a frame is said to have wavelet...... structure. The dilation of the wavelet building blocks in higher dimension is done via a square matrix which is usually taken to be integer valued. In this thesis we step away from the "usual" integer, expansive dilation and consider more general, expansive dilations. In most applications of wavelet frames...

  10. Quasi-uniform Space

    OpenAIRE

    Coghetto Roland

    2016-01-01

    In this article, using mostly Pervin [9], Kunzi [6], [8], [7], Williams [11] and Bourbaki [3] works, we formalize in Mizar [2] the notions of quasiuniform space, semi-uniform space and locally uniform space.

  11. Improved quality of intrafraction kilovoltage images by triggered readout of unexposed frames

    DEFF Research Database (Denmark)

    Poulsen, Per Rugaard; Jonassen, Johnny; Schmidt, Mai Lykkegaard

    2015-01-01

    of unexposed kV frames as a means to improve the kV image quality in a series of experiments and a theoretical model of the observed image quality improvements. Methods: A series of fluoroscopic images were acquired of a solid water phantom with an embedded gold marker and an air cavity with and without...... absolute error of 2.0% for the gold marker. Conclusions: A device that triggers readout of unexposed frames during kV fluoroscopy was built and shown to greatly improve the quality of intratreatment kV images. A simple theoretical model successfully described the CNR improvements with the device.......Purpose: The gantry-mounted kilovoltage (kV) imager of modern linear accelerators can be used forreal-time tumor localization during radiation treatment delivery. However, the kV image quality often suffers from cross-scatter from the megavoltage (MV) treatment beam. This study investigates readout...

  12. Ultra-fast framing camera tube

    Science.gov (United States)

    Kalibjian, Ralph

    1981-01-01

    An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.

  13. Tritium depth profiling in carbon by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Friedrich, M.; Pilz, W.; Sun, G.; Behrisch, R.; Garcia-Rosales, C.; Bekris, N.; Penzhorn, R.-D.

    2000-01-01

    Tritium depth profiling measurements by accelerator mass spectrometry have been performed at the facility installed at the Rossendorf 3 MV Tandetron. In order to achieve a uniform erosion at the target surface inside a commercial Cs ion sputtering source and to avoid edge effects, the samples were mechanically scanned and the signals were recorded only during sputtering at the centre of the sputtered area. The sputtered negative ions were mass analysed by the injection magnet of the Tandetron. Hydrogen and deuterium profiles were measured with the Faraday cup between the injection magnet and the accelerator, while the tritium was counted after the accelerator with semiconductor detectors. Depth profiles have been measured for carbon samples which had been exposed to the plasma at the first wall of the Garching fusion experiment ASDEX-Upgrade and from the European fusion experiment JET, Culham, UK

  14. Time delay control of power converters: Mixed frame and stationary-frame variants

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, P.C.; Tang, Y.

    2008-01-01

    In this paper, a mixed-frame and a stationary-frame time delay current controller are proposed for high precision reference tracking and disturbance rejection of power converters. In particular, the controllers use a proportional-resonant regulator in the stationary frame for regulating...... the positive and negative-sequence fundamental currents, which are known to directly influence the flow of active and reactive power in most energy conversion systems. Moreover, for the tracking or compensation of harmonics, the controllers include a time delay control path in either the synchronous...... or stationary frame, whose inherent feedback and feedforward structure can be proven to resemble a bank of resonant filters in either reference frames. Unlike other existing controllers, the proposed time delay controllers function by introducing multiple resonant peaks at only those harmonic frequencies...

  15. Quasi-uniform Space

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2016-09-01

    Full Text Available In this article, using mostly Pervin [9], Kunzi [6], [8], [7], Williams [11] and Bourbaki [3] works, we formalize in Mizar [2] the notions of quasiuniform space, semi-uniform space and locally uniform space.

  16. Do School Uniforms Fit?

    Science.gov (United States)

    White, Kerry A.

    2000-01-01

    In 1994, Long Beach (California) Unified School District began requiring uniforms in all elementary and middle schools. Now, half of all urban school systems and many suburban schools have uniform policies. Research on uniforms' effectiveness is mixed. Tightened dress codes may be just as effective and less litigious. (MLH)

  17. Saha equation in Rindler space

    Indian Academy of Sciences (India)

    Sanchari De

    2017-05-31

    May 31, 2017 ... scenario, the flat local geometry is called the Rindler space. For an illustration, let us consider two reference ... the local acceleration of the frame. To investigate Saha equation in a uniformly acceler- ... the best of our knowledge, the study of Saha equa- tion in Rindler space has not been reported earlier.

  18. Framing effects in medical situations: distinctions of attribute, goal and risky choice frames.

    Science.gov (United States)

    Peng, Jiaxi; Jiang, Yuan; Miao, Danmin; Li, Rui; Xiao, Wei

    2013-06-01

    To verify whether three different framing effects (risky choice, attribute and goal) exist in simulated medical situations and to analyse any differences. Medical decision-making problems were established, relating to medical skill evaluation, patient compliance and a selection of treatment options. All problems were described in positive and negative frame conditions. Significantly more positive evaluations were made if the doctor's medical records were described as 'of 100 patients, 70 patients became better' compared with those described as 'of 100 patients, 30 patients didn't become better'. Doctor's advice described in a negative frame resulted in significantly more decisions to comply, compared with advice described in a positive frame. Treatment options described in terms of survival rates resulted in significantly more adventurous choices compared with options described in terms of mortality rates. Decision-making reversal appeared in the risky choice and attribute frames, but not the goal frame. Framing effects were shown to exist in simulated medical situations, but there were significant differences among the three kinds of such effects.

  19. Message framing and perinatal decisions.

    Science.gov (United States)

    Haward, Marlyse F; Murphy, Ryan O; Lorenz, John M

    2008-07-01

    The purpose of this study was to explore the effect of information framing on parental decisions about resuscitation of extremely premature infants. Secondary outcomes focused on elucidating the impact of other variables on treatment choices and determining whether those effects would take precedence over any framing effects. This confidential survey study was administered to adult volunteers via the Internet. The surveys depicted a hypothetical vignette of a threatened delivery at gestational age of 23 weeks, with prognostic outcome information framed as either survival with lack of disability (positive frame) or chance of dying and likelihood of disability among survivors (negative frame). Participants were randomly assigned to receive either the positively or negatively framed vignette. They were then asked to choose whether they would prefer resuscitation or comfort care. After completing the survey vignette, participants were directed to a questionnaire designed to test the secondary hypothesis and to explore possible factors associated with treatment decisions. A total of 146 subjects received prognostic information framed as survival data and 146 subjects received prognostic information framed as mortality data. Overall, 24% of the sample population chose comfort care and 76% chose resuscitation. A strong trend was detected toward a framing effect on treatment preference; respondents for whom prognosis was framed as survival data were more likely to elect resuscitation. This framing effect was significant in a multivariate analysis controlling for religiousness, parental status, and beliefs regarding the sanctity of life. Of these covariates, only religiousness modified susceptibility to framing; participants who were not highly religious were significantly more likely to be influenced to opt for resuscitation by the positive frame than were participants who were highly religious. Framing bias may compromise efforts to approach prenatal counseling in a

  20. Final Report for 'Modeling Electron Cloud Diagnostics for High-Intensity Proton Accelerators'

    International Nuclear Information System (INIS)

    Veitzer, Seth A.

    2009-01-01

    Electron clouds in accelerators such as the ILC degrade beam quality and limit operating efficiency. The need to mitigate electron clouds has a direct impact on the design and operation of these accelerators, translating into increased cost and reduced performance. Diagnostic techniques for measuring electron clouds in accelerating cavities are needed to provide an assessment of electron cloud evolution and mitigation. Accurate numerical modeling of these diagnostics is needed to validate the experimental techniques. In this Phase I, we developed detailed numerical models of microwave propagation through electron clouds in accelerating cavities with geometries relevant to existing and future high-intensity proton accelerators such as Project X and the ILC. Our numerical techniques and simulation results from the Phase I showed that there was a high probability of success in measuring both the evolution of electron clouds and the effects of non-uniform electron density distributions in Phase II.

  1. The Technique for the Numerical Tolerances Estimations in the Construction of Compensated Accelerating Structures

    CERN Document Server

    Paramonov, V V

    2004-01-01

    The requirements to the cells manufacturing precision and tining in the multi-cells accelerating structures construction came from the required accelerating field uniformity, based on the beam dynamics demands. The standard deviation of the field distribution depends on accelerating and coupling modes frequencies deviations, stop-band width and coupling coefficient deviations. These deviations can be determined from 3D fields distribution for accelerating and coupling modes and the cells surface displacements. With modern software it can be done separately for every specified part of the cell surface. Finally, the cell surface displacements are defined from the cell dimensions deviations. This technique allows both to define qualitatively the critical regions and to optimize quantitatively the tolerances definition.

  2. 100-ps framing-camera tube

    International Nuclear Information System (INIS)

    Kalibjian, R.

    1978-01-01

    The optoelectronic framing-camera tube described is capable of recording two-dimensional image frames with high spatial resolution in the <100-ps range. Framing is performed by streaking a two-dimensional electron image across narrow slits. The resulting dissected electron line images from the slits are restored into framed images by a restorer deflector operating synchronously with the dissector deflector. The number of framed images on the tube's viewing screen equals the number of dissecting slits in the tube. Performance has been demonstrated in a prototype tube by recording 135-ps-duration framed images of 2.5-mm patterns at the cathode. The limitation in the framing speed is in the external drivers for the deflectors and not in the tube design characteristics. Faster frame speeds in the <100-ps range can be obtained by use of faster deflection drivers

  3. Direct drive acceleration of planar targets with the Nike KrF laser

    Energy Technology Data Exchange (ETDEWEB)

    Pawley, C.J.; Sethian, J.D.; Bodner, S.E. [Naval Research Lab., Washington, DC (United States). Plasma Physics Div.] [and others

    1999-02-01

    Nike is a multi-kilojoule KrF laser with very high beam uniformity ({Delta}I/I<0.2% with all 36 overlapped beams), and the capability to accelerate relatively thick targets on a low adiabat under conditions scalable to direct drive ICF. In a first set of experiments we determined the effect of the imprinting by varying the uniformity of the foot of the laser pulse and measuring the growth of the subsequent Rayleigh-Taylor instability. We found that the lower the imprint, the longer the mass modulations take to reach a given level. This is in quantitative agreement with our 2-D hydrodynamics simulations. The results are promising for direct drive with a very uniform laser. (orig.) 4 refs.

  4. Tripartite entanglement of bosonic systems in a noninertial frame beyond the single- mode approximation

    Directory of Open Access Journals (Sweden)

    M Soltani

    2015-12-01

    Full Text Available In this work, we generalize the entanglement of three-qbit Bosonic systems beyond the single-mode approximation when one of the observers is accelerated. For this purpose, we review the effects of acceleration on field modes and quantum states. The single-mode approximation and beyond the single-mode approximation methods are introduced. After this brief introduction, the main problem of this paper, tripartite entanglement of bosonic systems in a noninertial frame beyond the single- mode approximation is investigated. The tripartite entangled states have different classes with GHZ and W states being most important. Here, we choose &pi-tangle as a measure of tripartite entanglement. If the three parties share GHZ state, the corresponding &pi-tangle will increase by increasing acceleration for some Unruh modes. This phenomenon, increasing entanglement, has never been observed in the single-mode approximation for bosonic case. Moreover, the &pi-tangle dose not exhibit a monotonic behavior with increasing acceleration. In the infinite acceleration limit, the &pi-tangle goes to different nonzero values for distinct Unruh modes. Unlike GHZ state, the entanglement of the W state shows only monotonically increasing and decreasing behaviors with increasing acceleration. Also, the entanglement for all possible choices of Unruh modes approaches only 0.176 in the high acceleration limit. Therefore, according to the quantum entanglement, there is no distinction between the single-mode approximation and beyond the single-mode approximation methods in this limit.

  5. Bell's twin rockets non-inertial length enigma resolved by real geometry

    Science.gov (United States)

    Coleman, Brian

    A priori uniformity and monotonicity of the 'non-inertial length' expansion of a uniformly co-accelerating medium, uniquely yield an unfamiliar 'hemicoid' real-values metric surface ϒ in R3 . ϒ (τ, l) hosts congruent helicoidally distributed fixed-l 'hemix world-lines' tracing medium increments' clock times τ and crossed by fixed- τ medium helices of parameterized length λ sharing comoving 'non-inertial frames'. Radar intervals and expansion factor ∂λ / ∂l = √ (1 +v2 /c2) conform to requirements established in Coleman, Results in Physics,6, 2016-Minkowski spacetime does not apply to a homogeneously accelerating medium. Co-directional radar paths on ϒ mapped from home frame chart diagonals crossing hyperbolic world-lines, surf 'horizon' increment hemices, whereas counter-directional radar paths tend to 'overlap' horizon medium helices. They also traverse each medium expansion helix at respectively identical angles and geodesic curvatures, independently of differing rocket emission times. Surface ϒ 's real metric is: ds2 = dτ2 + dλ2 +[ 2 tanhτ . (tanhτ - 1 / coshτ) / √ (1 +tanh2 τ) ] dτ . dλ .

  6. Novel applications of particle accelerators to radiotherapy

    International Nuclear Information System (INIS)

    Kreiner, A.J.; Burlon, A.A.; Universidad Nacional de San Martin, Villa Ballester

    2002-01-01

    Charged hadrons (protons and heavier ions) have very definite advantages over photons as far as radiotherapy applications are concerned. They allow for much better spatial dose localization due to their charge, relatively high mass and nature of the energy deposition process. In the frame of an attempt to promote the introduction of hadrontherapy in Argentina an external beam facility has been installed at our tandem accelerator TANDAR. The advantages of heavy ions can only be fully exploited for tumors of well defined localization. In certain types of malignancies, however, the region infiltrated by tumor cells is diffuse, with no sharp boundaries and with microscopic ramifications. In such cases (particularly in certain brain cancers) a more sophisticated scheme has been suggested called boron neutron capture therapy (BNCT). In this work, the use of the Tandar accelerator to produce neutrons for feasibility studies for BNCT through low-energy proton beams on a thick LiF target is being briefly described. Studies on the 13 C(d,n) reaction and a comparison with other neutron-producing reactions are also mentioned. Simulation work to optimize an accelerator-based neutron production target is discussed. A project is being prepared to develop a small proton accelerator in Argentina. Technical specifications of this machine are briefly discussed. (author)

  7. Simulation of density measurements in plasma wakefields using photon acceleration

    Directory of Open Access Journals (Sweden)

    Muhammad Firmansyah Kasim

    2015-03-01

    Full Text Available One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  8. Experimental measurement of unsteady drag on shock accelerated micro-particles

    Science.gov (United States)

    Bordoloi, Ankur; Martinez, Adam; Prestridge, Katherine

    2016-11-01

    The unsteady drag history of shock accelerated micro-particles in air is investigated in the Horizontal Shock Tube (HST) facility at Los Alamos National laboratory. Drag forces are estimated based on particle size, particle density, and instantaneous velocity and acceleration measured on hundreds of post-shock particle tracks. We use previously implemented 8-frame Particle Tracking Velocimetry/Anemometry (PTVA) diagnostics to analyze particles in high spatiotemporal resolution from individual particle trajectories. We use a simultaneous LED based shadowgraph to register shock location with respect to a moving particle in each frame. To measure particle size accurately, we implement a Phase Doppler Particle Analyzer (PDPA) in synchronization with the PTVA. In this presentation, we will corroborate with more accuracy our earlier observation that post-shock unsteady drag coefficients (CD(t)) are manifold times higher than those predicted by theoretical models. Our results will also show that all CD(t) measurements collapse on a master-curve for a range of particle size, density, Mach number and Reynolds number when time is normalized by a shear velocity based time scale, t* = d/(uf-up) , where d is particle diameter, and uf and up are post-shock fluid and particle velocities.

  9. Observable Zitterbewegung in curved spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Kobakhidze, Archil, E-mail: archilk@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Manning, Adrian, E-mail: a.manning@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Tureanu, Anca, E-mail: anca.tureanu@helsinki.fi [Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki (Finland)

    2016-06-10

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  10. Observable Zitterbewegung in curved spacetimes

    Science.gov (United States)

    Kobakhidze, Archil; Manning, Adrian; Tureanu, Anca

    2016-06-01

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  11. Conformal frame dependence of inflation

    International Nuclear Information System (INIS)

    Domènech, Guillem; Sasaki, Misao

    2015-01-01

    Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case

  12. Conformal frame dependence of inflation

    Energy Technology Data Exchange (ETDEWEB)

    Domènech, Guillem; Sasaki, Misao, E-mail: guillem.domenech@yukawa.kyoto-u.ac.jp, E-mail: misao@yukawa.kyoto-u.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2015-04-01

    Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case.

  13. Mass, charge, and energy separation by selective acceleration with a traveling potential hill

    Science.gov (United States)

    Tung, L. Schwager; Barr, W. L.; Lowder, R. S.; Post, R. F.

    1996-10-01

    A traveling electric potential hill has been used to generate an ion beam with an energy distribution that is mass dependent from a monoenergetic ion beam of mixed masses. This effect can be utilized as a novel method for mass separation applied to identification or enrichment of ions (e.g., of elements, isotopes, or molecules). This theory for mass-selective acceleration is presented here and is shown to be confirmed by experiment and by a time-dependent particle-in-cell computer simulation. Results show that monoenergetic ions with the particular mass of choice are accelerated by controlling the hill potential and the hill velocity. The hill velocity is typically 20%-30% faster than the ions to be accelerated. The ability of the hill to pickup a particular mass uses the fact that small kinetic energy differences in the lab frame appear much larger in the moving hill frame. Ions will gain energy from the approaching hill if their relative energy in the moving hill frame is less than the peak potential of the hill. The final energy of these accelerated ions can be several times the source energy, which facilitates energy filtering for mass purification or identification. If the hill potential is chosen to accelerate multiple masses, the heaviest mass will have the greatest final energy. Hence, choosing the appropriate hill potential and collector retarding voltage will isolate ions with the lightest, heaviest, or intermediate mass. In the experimental device, called a Solitron, purified 20Ne and 22Ne are extracted from a ribbon beam of neon that is originally composed of 20Ne:22Ne in the natural ratio of 91:9. The isotopic content of the processed beam is determined by measuring the energy distribution of the detected current. These results agree with the theory. In addition to mass selectivity, our theory can also be applied to the filtration of an ion beam according to charge state or energy. Because of this variety of properties, the Solitron is envisioned to

  14. Critical heat flux of forced convection boiling in an oscilating acceleration field. Pt. 1

    International Nuclear Information System (INIS)

    Otsuji, T.; Kurosawa, A.

    1982-01-01

    The influence of periodically varying acceleration on critical heat flux (CHF) of Freon-113 flowing upward in a uniformly heated vertical annular channel has been studied experimentally. The freon loop was oscillated vertically to determine the ratio of CHF in the oscillating acceleration field to the corresponding stationary value. The amplitude of inlet flow oscillation induced by variation of acceleration, which causes early CHF, is proportional to the acceleration amplitude. The dependence of inlet flow rate on the oscillating acceleration decreases with increasing inlet subcooling, and no oscillation of inlet flow is observed in the case of negative exit quality (subcooled boiling). Nevertheless the degradation of CHF is more remarkable in the low quality region. This result suggests the necessity to introduce an other mechanism of early CHF than flow oscillation. (orig.)

  15. Making students' frames explicit

    DEFF Research Database (Denmark)

    Nielsen, Louise Møller; Hansen, Poul Henrik Kyvsgaard

    2016-01-01

    Framing is a vital part of the design and innovation process. Frames are cognitive shortcuts (i.e. metaphors) that enable designers to connect insights about i.e. market opportunities and users needs with a set of solution principles and to test if this connection makes sense. Until now, framing...

  16. Spiral wobbling beam illumination uniformity in HIF fuel target implosion

    Directory of Open Access Journals (Sweden)

    Kawata S.

    2013-11-01

    Full Text Available A few % wobbling-beam illumination nonuniformity is realized in heavy ion inertial confinement fusion (HIF throughout the heavy ion beam (HIB driver pulse by a newly introduced spiraling beam axis motion in the first two rotations. The wobbling HIB illumination was proposed to realize a uniform implosion in HIF. However, the initial imprint of the wobbling HIBs was a serious problem and introduces a large unacceptable energy deposition nonuniformity. In the wobbling HIBs illumination, the illumination nonuniformity oscillates in time and space. The oscillating-HIB energy deposition may produce a time-dependent implosion acceleration, which reduces the Rayleigh-Taylor (R-T growth [Laser Part. Beams 11, 757 (1993, Nuclear Inst. Methods in Phys. Res. A 606, 152 (2009, Phys. Plasmas 19, 024503 (2012] and the implosion nonuniformity. The wobbling HIBs can be generated in HIB accelerators and the oscillating frequency may be several 100 MHz ∼ 1 GHz [Phys. Rev. Lett. 104, 254801 (2010]. Three-dimensional HIBs illumination computations present that the few % wobbling HIBs illumination nonuniformity oscillates with the same wobbling HIBs frequency.

  17. Frames and generalized shift-invariant systems

    DEFF Research Database (Denmark)

    Christensen, Ole

    2004-01-01

    With motivation from the theory of Hilbert-Schmidt operators we review recent topics concerning frames in L 2 (R) and their duals. Frames are generalizations of orthonormal bases in Hilbert spaces. As for an orthonormal basis, a frame allows each element in the underlying Hilbert space...... to be written as an unconditionally convergent infinite linear combination of the frame elements; however, in contrast to the situation for a basis, the coefficients might not be unique. We present the basic facts from frame theory and the motivation for the fact that most recent research concentrates on tight...... frames or dual frame pairs rather than general frames and their canonical dual. The corresponding results for Gabor frames and wavelet frames are discussed in detail....

  18. The algorithm of random length sequences synthesis for frame synchronization of digital television systems

    Directory of Open Access Journals (Sweden)

    Аndriy V. Sadchenko

    2015-12-01

    Full Text Available Digital television systems need to ensure that all digital signals processing operations are performed simultaneously and consistently. Frame synchronization dictated by the need to match phases of transmitter and receiver so that it would be possible to identify the start of a frame. As a frame synchronization signals are often used long length binary sequence with good aperiodic autocorrelation function. Aim: This work is dedicated to the development of the algorithm of random length sequences synthesis. Materials and Methods: The paper provides a comparative analysis of the known sequences, which can be used at present as synchronization ones, revealed their advantages and disadvantages. This work proposes the algorithm for the synthesis of binary synchronization sequences of random length with good autocorrelation properties based on noise generator with a uniform distribution law of probabilities. A "white noise" semiconductor generator is proposed to use as the initial material for the synthesis of binary sequences with desired properties. Results: The statistical analysis of the initial implementations of the "white noise" and synthesized sequences for frame synchronization of digital television is conducted. The comparative analysis of the synthesized sequences with known ones was carried out. The results show the benefits of obtained sequences in compare with known ones. The performed simulations confirm the obtained results. Conclusions: Thus, the search algorithm of binary synchronization sequences with desired autocorrelation properties received. According to this algorithm, the sequence can be longer in length and without length limitations. The received sync sequence can be used for frame synchronization in modern digital communication systems that will increase their efficiency and noise immunity.

  19. Power to the frame: bringing sociology back to frame analysis

    NARCIS (Netherlands)

    Vliegenthart, R.; van Zoonen, L.

    2011-01-01

    This article critically reviews current frame and framing research in media and communication studies. It is first argued that most authors fail to distinguish between ‘frame’ and ‘framing’ and therewith produce a conceptual confusion and imprecision that is not conducive to the field. Second, it is

  20. 49 CFR 393.201 - Frames.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Frames. 393.201 Section 393.201 Transportation... SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems § 393.201 Frames. (a) The frame or chassis of each commercial motor vehicle shall not be cracked, loose, sagging or...

  1. Games Uniforms Unveiled

    Institute of Scientific and Technical Information of China (English)

    Linda

    2008-01-01

    The uniforms for Beijing Olympics’ workers, technical staff and volunteers have been unveiled to mark the 200-day countdown to the Games. The uniforms feature the key element of the clouds of promise and will be in three colors:red for Beijing Olympic Games Committee staff, blue

  2. DYNAPO 4 - a fluid system and frames analysis computer program

    International Nuclear Information System (INIS)

    Lefter, J.D.; Ahdout, H.

    1982-01-01

    DYNAPO 4 is a user oriented specialized computer program, capable of analyzing three-dimensional linear elastic piping systems or frames for static loads, dynamic loads represented by acceleration response spectra, transient dynamic loads represented by harmonic, polynomial of second order, and time history forcing functions. DYNAPO 4 has plotting capability, which plots the input configuration of the piping system or of the structure and also plots its deformed shape after the load is applied. DYNAPO 4 performs the analysis for ASME Section III Class 1, Class 2, and 3, piping, and provides the user with stress reports as per ASME and ANSI Code requirements. 3 refs

  3. Measurement of activity distribution using photostimulable phosphor imaging plates in decommissioned 10 MV medical linear accelerator.

    Science.gov (United States)

    Fujibuchi, Toshioh; Yonai, Shunsuke; Yoshida, Masahiro; Sakae, Takeji; Watanabe, Hiroshi; Abe, Yoshihisa; Itami, Jun

    2014-08-01

    Photonuclear reactions generate neutrons in the head of the linear accelerator. Therefore, some parts of the linear accelerator can become activated. Such activated materials must be handled as radioactive waste. The authors attempted to investigate the distribution of induced radioactivity using photostimulable phosphor imaging plates. Autoradiographs were produced from some parts of the linear accelerator (the target, upper jaw, multileaf collimator and shielding). The levels of induced radioactivity were confirmed to be non-uniform within each part from the autoradiographs. The method was a simple and highly sensitive approach to evaluating the relative degree of activation of the linear accelerators, so that appropriate materials management procedures can be carried out.

  4. Frames and extension problems I

    DEFF Research Database (Denmark)

    Christensen, Ole

    2014-01-01

    In this article we present a short survey of frame theory in Hilbert spaces. We discuss Gabor frames and wavelet frames and set the stage for a discussion of various extension principles; this will be presented in the article Frames and extension problems II (joint with H.O. Kim and R.Y. Kim)....

  5. Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate

    International Nuclear Information System (INIS)

    C.Z. Cheng; Y. Ren; G.S. Choe; Y.-J. Moon

    2003-01-01

    A physical mechanism of flares, in particular for the flare rise phase, has emerged from our 2-1/2-dimensional resistive MHD simulations. The dynamical evolution of current-sheet formation and magnetic reconnection and flux-rope acceleration subject to continuous, slow increase of magnetic shear in the arcade are studied by employing a non-uniform anomalous resistivity in the reconnecting current sheet under gravity. The simulation results directly relate the flux rope's accelerated rising motion with an enhanced magnetic reconnection rate and thus an enhanced reconnection electric field in the current sheet during the flare rise phase. The simulation results provide good quantitative agreements with observations of the acceleration of flux rope, which manifests in the form of SXR ejecta or erupting filament or CMEs, in the low corona. Moreover, for the X-class flare events studied in this paper the peak reconnection electric field is about O(10 2 V/m) or larger, enough to accelerate p articles to over 100 keV in a field-aligned distance of 10 km. Nonthermal electrons thus generated can produce hard X-rays, consistent with impulsive HXR emission observed during the flare rise phase

  6. A note on the standard dual frame of a wavelet frame with three-scale

    International Nuclear Information System (INIS)

    Chen Qingjiang; Wei Zongtian; Feng Jinshun

    2009-01-01

    In this paper, it is shown that there exist wavelet frames generated by two functions which have good dual wavelet frames, but for which the standard dual wavelet frame does not consist of wavelets. That is to say, the standard dual wavelet frame cannot be generated by the translations and dilations of a single function. Relation to some physical theories such as entropy and E-infinity theory is also discussed.

  7. Measuring the quality of a quantum reference frame: The relative entropy of frameness

    International Nuclear Information System (INIS)

    Gour, Gilad; Marvian, Iman; Spekkens, Robert W.

    2009-01-01

    In the absence of a reference frame for transformations associated with group G, any quantum state that is noninvariant under the action of G may serve as a token of the missing reference frame. We here present a measure of the quality of such a token: the relative entropy of frameness. This is defined as the relative entropy distance between the state of interest and the nearest G-invariant state. Unlike the relative entropy of entanglement, this quantity is straightforward to calculate, and we find it to be precisely equal to the G-asymmetry, a measure of frameness introduced by Vaccaro et al. It is shown to provide an upper bound on the mutual information between the group element encoded into the token and the group element that may be extracted from it by measurement. In this sense, it quantifies the extent to which the token successfully simulates a full reference frame. We also show that despite a suggestive analogy from entanglement theory, the regularized relative entropy of frameness is zero and therefore does not quantify the rate of interconversion between the token and some standard form of quantum reference frame. Finally, we show how these investigations yield an approach to bounding the relative entropy of entanglement.

  8. A scanning point source for quality control of FOV uniformity in GC-PET imaging

    International Nuclear Information System (INIS)

    Bergmann, H.; Minear, G.; Dobrozemsky, G.; Nowotny, R.; Koenig, B.

    2002-01-01

    Aim: PET imaging with coincidence cameras (GC-PET) requires additional quality control procedures to check the function of coincidence circuitry and detector zoning. In particular, the uniformity response over the field of view needs special attention since it is known that coincidence counting mode may suffer from non-uniformity effects not present in single photon mode. Materials and methods: An inexpensive linear scanner with a stepper motor and a digital interface to a PC with software allowing versatile scanning modes was developed. The scanner is used with a source holder containing a Sodium-22 point source. While moving the source along the axis of rotation of the GC-PET system, a tomographic acquisition takes place. The scan covers the full axial field of view of the 2-D or 3-D scatter frame. Depending on the acquisition software, point source scanning takes place continuously while only one projection is acquired or is done in step-and-shoot mode with the number of positions equal to the number of gantry steps. Special software was developed to analyse the resulting list mode acquisition files and to produce an image of the recorded coincidence events of each head. Results: Uniformity images of coincidence events were obtained after further correction for systematic sensitivity variations caused by acquisition geometry. The resulting images are analysed visually and by calculating NEMA uniformity indices as for a planar flood field. The method has been applied successfully to two different brands of GC-PET capable gamma cameras. Conclusion: Uniformity of GC-PET can be tested quickly and accurately with a routine QC procedure, using a Sodium-22 scanning point source and an inexpensive mechanical scanning device. The method can be used for both 2-D and 3-D acquisition modes and fills an important gap in the quality control system for GC-PET

  9. Lateral Displacement And Shear Lag Effect Of High-Rise Buildings With Diagrid SystemThat Is Constructed Above A Frame

    Directory of Open Access Journals (Sweden)

    Abd. Samat Roslida

    2017-01-01

    Full Text Available Diagrid system has gained a wide acceptance in the design of tall buildings due to its many advantages including its high structural efficiency in resisting both gravity and lateral loads. Most diagrid structures that had been studied have full triangulated members from the ground level to the top of the buildings where comparison in the effectiveness in minimizing the lateral displacement was often made between structures with full diagrid, frame and outrigger system. Nevertheless, no study has been performed on the effectiveness of the diagrid that is constructed above a frame system. The objective of this research is to understand the behavior of the lateral displacement and shear lag effect due to wind load when the diagrid structure is constructed above a frame. Models of sixty storey buildings were analyzed by using Staad.Pro software. The level where the diagrid members started and the spacing of vertical base columns of the frame were altered. The lateral displacement and shear lag effect resembled closely of those of the model of full diagrid when the diagrid was started at level 3, and the vertical base columns were uniformly spaced at 6 metres.

  10. Parametric Modelling of As-Built Beam Framed Structure in Bim Environment

    Science.gov (United States)

    Yang, X.; Koehl, M.; Grussenmeyer, P.

    2017-02-01

    A complete documentation and conservation of a historic timber roof requires the integration of geometry modelling, attributional and dynamic information management and results of structural analysis. Recently developed as-built Building Information Modelling (BIM) technique has the potential to provide a uniform platform, which provides possibility to integrate the traditional geometry modelling, parametric elements management and structural analysis together. The main objective of the project presented in this paper is to develop a parametric modelling tool for a timber roof structure whose elements are leaning and crossing beam frame. Since Autodesk Revit, as the typical BIM software, provides the platform for parametric modelling and information management, an API plugin, able to automatically create the parametric beam elements and link them together with strict relationship, was developed. The plugin under development is introduced in the paper, which can obtain the parametric beam model via Autodesk Revit API from total station points and terrestrial laser scanning data. The results show the potential of automatizing the parametric modelling by interactive API development in BIM environment. It also integrates the separate data processing and different platforms into the uniform Revit software.

  11. DEM simulation of granular flows in a centrifugal acceleration field

    Science.gov (United States)

    Cabrera, Miguel Angel; Peng, Chong; Wu, Wei

    2017-04-01

    The main purpose of mass-flow experimental models is abstracting distinctive features of natural granular flows, and allow its systematic study in the laboratory. In this process, particle size, space, time, and stress scales must be considered for the proper representation of specific phenomena [5]. One of the most challenging tasks in small scale models, is matching the range of stresses and strains among the particle and fluid media observed in a field event. Centrifuge modelling offers an alternative to upscale all gravity-driven processes, and it has been recently employed in the simulation of granular flows [1, 2, 3, 6, 7]. Centrifuge scaling principles are presented in Ref. [4], collecting a wide spectrum of static and dynamic models. However, for the case of kinematic processes, the non-uniformity of the centrifugal acceleration field plays a major role (i.e., Coriolis and inertial effects). In this work, we discuss a general formulation for the centrifugal acceleration field, implemented in a discrete element model framework (DEM), and validated with centrifuge experimental results. Conventional DEM simulations relate the volumetric forces as a function of the gravitational force Gp = mpg. However, in the local coordinate system of a rotating centrifuge model, the cylindrical centrifugal acceleration field needs to be included. In this rotating system, the centrifugal acceleration of a particle depends on the rotating speed of the centrifuge, as well as the position and speed of the particle in the rotating model. Therefore, we obtain the formulation of centrifugal acceleration field by coordinate transformation. The numerical model is validated with a series of centrifuge experiments of monodispersed glass beads, flowing down an inclined plane at different acceleration levels and slope angles. Further discussion leads to the numerical parameterization necessary for simulating equivalent granular flows under an augmented acceleration field. The premise of

  12. Competitive Framing

    OpenAIRE

    Ran Spiegler

    2014-01-01

    I present a simple framework for modeling two-firm market competition when consumer choice is "frame-dependent", and firms use costless "marketing messages" to influence the consumer's frame. This framework embeds several recent models in the "behavioral industrial organization" literature. I identify a property that consumer choice may satisfy, which extends the concept of Weighted Regularity due to Piccione and Spiegler (2012), and provide a characterization of Nash equilibria under this pr...

  13. Earthquake Damping Device for Steel Frame

    Science.gov (United States)

    Zamri Ramli, Mohd; Delfy, Dezoura; Adnan, Azlan; Torman, Zaida

    2018-04-01

    Structures such as buildings, bridges and towers are prone to collapse when natural phenomena like earthquake occurred. Therefore, many design codes are reviewed and new technologies are introduced to resist earthquake energy especially on building to avoid collapse. The tuned mass damper is one of the earthquake reduction products introduced on structures to minimise the earthquake effect. This study aims to analyse the effectiveness of tuned mass damper by experimental works and finite element modelling. The comparisons are made between these two models under harmonic excitation. Based on the result, it is proven that installing tuned mass damper will reduce the dynamic response of the frame but only in several input frequencies. At the highest input frequency applied, the tuned mass damper failed to reduce the responses. In conclusion, in order to use a proper design of damper, detailed analysis must be carried out to have sufficient design based on the location of the structures with specific ground accelerations.

  14. Message framing in social networking sites.

    Science.gov (United States)

    Kao, Danny Tengti; Chuang, Shih-Chieh; Wang, Sui-Min; Zhang, Lei

    2013-10-01

    Online social networking sites represent significant new opportunities for Internet advertisers. However, results based on the real world cannot be generalized to all virtual worlds. In this research, the moderating effects of need for cognition (NFC) and knowledge were applied to examine the impact of message framing on attitudes toward social networking sites. A total of 216 undergraduates participated in the study. Results reveal that for social networking sites, while high-NFC individuals form more favorable attitudes toward negatively framed messages than positively framed messages, low-NFC individuals form more favorable attitudes toward positively framed messages than negatively framed messages. In addition, low-knowledge individuals demonstrate more favorable attitudes toward negatively framed messages than positively framed messages; however, the framing effect does not differentially affect the attitudes of high-knowledge individuals. Furthermore, the framing effect does not differentially affect the attitudes of high-NFC individuals with high knowledge. In contrast, low-NFC individuals with low knowledge hold more favorable attitudes toward positively framed messages than negatively framed messages.

  15. Traditional timber frames

    NARCIS (Netherlands)

    Jorissen, A.J.M.; Hamer, den J.; Leijten, A.J.M.; Salenikovich, A.

    2014-01-01

    Due to new possibilities traditional timber framing has become increasingly popular since the beginning of the 21e century. Although traditional timber framing has been used for centuries, the expected mechanical behaviour is not dealt with in great detail in building codes, guidelines or text

  16. On radiation heating of superconducting magnets of the accelerating-storage complex

    International Nuclear Information System (INIS)

    Maslov, M.A.; Mokhov, N.V.

    1981-01-01

    To analyze regularities of energy release formation in a superconducting winding (SCW) of superconducting magnets (SCM) of the IHEP accelerating-storage facility the energy release values in the SCM when 400-3000 GeV proton beam incidence onto the SCM vacuum chamber are calculated. Two SCM modifications (a dipole one and a quadrupole one) and two modes of irradiation (uniform irradiation along the SCM azimuth and length and a thin beam incidence uniform along the SCM length) are considered. It is shown that for the SCM with the 26 cm aperture at the 1 mrad angle of incidence 25% of the initial proton energy is released [ru

  17. Comparative study of active plasma lenses in high-quality electron accelerator transport lines

    Science.gov (United States)

    van Tilborg, J.; Barber, S. K.; Benedetti, C.; Schroeder, C. B.; Isono, F.; Tsai, H.-E.; Geddes, C. G. R.; Leemans, W. P.

    2018-05-01

    Electrically discharged active plasma lenses (APLs) are actively pursued in compact high-brightness plasma-based accelerators due to their high-gradient, tunable, and radially symmetric focusing properties. In this manuscript, the APL is experimentally compared with a conventional quadrupole triplet, highlighting the favorable reduction in the energy dependence (chromaticity) in the transport line. Through transport simulations, it is explored how the non-uniform radial discharge current distribution leads to beam-integrated emittance degradation and a charge density reduction at focus. However, positioning an aperture at the APL entrance will significantly reduce emittance degradation without additional loss of charge in the high-quality core of the beam. An analytical model is presented that estimates the emittance degradation from a short beam driving a longitudinally varying wakefield in the APL. Optimizing laser plasma accelerator operation is discussed where emittance degradation from the non-uniform discharge current (favoring small beams inside the APL) and wakefield effects (favoring larger beam sizes) is minimized.

  18. Uniform Sampling Table Method and its Applications II--Evaluating the Uniform Sampling by Experiment.

    Science.gov (United States)

    Chen, Yibin; Chen, Jiaxi; Chen, Xuan; Wang, Min; Wang, Wei

    2015-01-01

    A new method of uniform sampling is evaluated in this paper. The items and indexes were adopted to evaluate the rationality of the uniform sampling. The evaluation items included convenience of operation, uniformity of sampling site distribution, and accuracy and precision of measured results. The evaluation indexes included operational complexity, occupation rate of sampling site in a row and column, relative accuracy of pill weight, and relative deviation of pill weight. They were obtained from three kinds of drugs with different shape and size by four kinds of sampling methods. Gray correlation analysis was adopted to make the comprehensive evaluation by comparing it with the standard method. The experimental results showed that the convenience of uniform sampling method was 1 (100%), odds ratio of occupation rate in a row and column was infinity, relative accuracy was 99.50-99.89%, reproducibility RSD was 0.45-0.89%, and weighted incidence degree exceeded the standard method. Hence, the uniform sampling method was easy to operate, and the selected samples were distributed uniformly. The experimental results demonstrated that the uniform sampling method has good accuracy and reproducibility, which can be put into use in drugs analysis.

  19. Nonlinear static analysis of steel frames with semi rigid beam to column connections using cruciform element

    Directory of Open Access Journals (Sweden)

    Vahid Reza Afkhami

    2017-12-01

    Full Text Available In the steel frames, beam-column connections are traditionally assumed to be rigid or pinned, but in the steel frames, most types of beam-column connections are semi-rigid. Recent studies and some new codes, especially EC3 and EC4, include methods and formulas to estimate the resistance and stiffness of the panel zone. Because of weaknesses of EC3 and EC4 in some cases, Bayo et al.  proposed a new component-based method (cruciform element method to model internal and external semi-rigid connections that revived and modified EC methods. The nonlinear modelling of structures plays an important role in the analysis and design of structures and nonlinear static analysis is a rather simple and efficient technique for analysis of structures. This paper presents nonlinear static (pushover analysis technique by new nonlinearity factor and Bayo et al. model of two types of semi-rigid connections, end plate connection and top and seat angles connection. Two types of lateral loading, uniform and triangular distributions are considered.  Results show that the frames with top and seat angles connection have fewer initial stiffness than frames with semi-rigid connection and P-Δ effect more decreases base shear capacity in the case of top and seat angles connection. P-Δ effect in decrease of base shear capacity increases with the increase of number of stories.

  20. The Use of Conditional Probability Integral Transformation Method for Testing Accelerated Failure Time Models

    Directory of Open Access Journals (Sweden)

    Abdalla Ahmed Abdel-Ghaly

    2016-06-01

    Full Text Available This paper suggests the use of the conditional probability integral transformation (CPIT method as a goodness of fit (GOF technique in the field of accelerated life testing (ALT, specifically for validating the underlying distributional assumption in accelerated failure time (AFT model. The method is based on transforming the data into independent and identically distributed (i.i.d Uniform (0, 1 random variables and then applying the modified Watson statistic to test the uniformity of the transformed random variables. This technique is used to validate each of the exponential, Weibull and lognormal distributions' assumptions in AFT model under constant stress and complete sampling. The performance of the CPIT method is investigated via a simulation study. It is concluded that this method performs well in case of exponential and lognormal distributions. Finally, a real life example is provided to illustrate the application of the proposed procedure.

  1. Application of Fourier transform to MHD flow over an accelerated plate with partial-slippage

    Directory of Open Access Journals (Sweden)

    Salman Ahmad

    2014-06-01

    Full Text Available Magneto-Hydrodynamic (MHD flow over an accelerated plate is investigated with partial slip conditions. Generalized Fourier Transform is used to get the exact solution not only for uniform acceleration but also for variable acceleration. The numerical solution is obtained by using linear finite element method in space and One-Step-θ-scheme in time. The resulting discretized algebraic systems are solved by applying geometric-multigrid approach. Numerical solutions are compared with the obtained Fourier transform results. Many interesting results related with slippage and MHD effects are discussed in detail through graphical sketches and tables. Application of Dirac-Delta function is one of the main features of present work.

  2. Accelerated Computing in Magnetic Resonance Imaging: Real-Time Imaging Using Nonlinear Inverse Reconstruction

    Directory of Open Access Journals (Sweden)

    Sebastian Schaetz

    2017-01-01

    Full Text Available Purpose. To develop generic optimization strategies for image reconstruction using graphical processing units (GPUs in magnetic resonance imaging (MRI and to exemplarily report on our experience with a highly accelerated implementation of the nonlinear inversion (NLINV algorithm for dynamic MRI with high frame rates. Methods. The NLINV algorithm is optimized and ported to run on a multi-GPU single-node server. The algorithm is mapped to multiple GPUs by decomposing the data domain along the channel dimension. Furthermore, the algorithm is decomposed along the temporal domain by relaxing a temporal regularization constraint, allowing the algorithm to work on multiple frames in parallel. Finally, an autotuning method is presented that is capable of combining different decomposition variants to achieve optimal algorithm performance in different imaging scenarios. Results. The algorithm is successfully ported to a multi-GPU system and allows online image reconstruction with high frame rates. Real-time reconstruction with low latency and frame rates up to 30 frames per second is demonstrated. Conclusion. Novel parallel decomposition methods are presented which are applicable to many iterative algorithms for dynamic MRI. Using these methods to parallelize the NLINV algorithm on multiple GPUs, it is possible to achieve online image reconstruction with high frame rates.

  3. The role of message framing in promoting MMR vaccination: evidence of a loss-frame advantage.

    Science.gov (United States)

    Abhyankar, Purva; O'Connor, Daryl B; Lawton, Rebecca

    2008-01-01

    This study examined the effects of message framing on intentions to obtain the measles, mumps and rubella (MMR) vaccine for one's child and investigated whether Theory of Planned Behaviour (TPB) and perceived outcome efficacy variables mediate and/or moderate message framing effects. One hundred and forty women read either a loss-framed or gain-framed message and then completed measures assessing their intentions to obtain the MMR vaccine for their child, and TPB and outcome efficacy variables. Exposure to the loss frame increased intentions to obtain the MMR vaccine and influenced perceptions of outcome efficacy. This suggests that outcome efficacy, but not other TPB variables may mediate framing effects within the context of MMR vaccination. Message frame, in addition to TPB variables, significantly predicted unique variance in behavioural intentions. These findings are discussed within the context of Prospect Theory, perceived risk and prevention/detection behaviours.

  4. High-performance modeling of plasma-based acceleration and laser-plasma interactions

    Science.gov (United States)

    Vay, Jean-Luc; Blaclard, Guillaume; Godfrey, Brendan; Kirchen, Manuel; Lee, Patrick; Lehe, Remi; Lobet, Mathieu; Vincenti, Henri

    2016-10-01

    Large-scale numerical simulations are essential to the design of plasma-based accelerators and laser-plasma interations for ultra-high intensity (UHI) physics. The electromagnetic Particle-In-Cell (PIC) approach is the method of choice for self-consistent simulations, as it is based on first principles, and captures all kinetic effects, and also scale favorably to many cores on supercomputers. The standard PIC algorithm relies on second-order finite-difference discretization of the Maxwell and Newton-Lorentz equations. We present here novel formulations, based on very high-order pseudo-spectral Maxwell solvers, which enable near-total elimination of the numerical Cherenkov instability and increased accuracy over the standard PIC method for standard laboratory frame and Lorentz boosted frame simulations. We also present the latest implementations in the PIC modules Warp-PICSAR and FBPIC on the Intel Xeon Phi and GPU architectures. Examples of applications will be given on the simulation of laser-plasma accelerators and high-harmonic generation with plasma mirrors. Work supported by US-DOE Contracts DE-AC02-05CH11231 and by the European Commission through the Marie Slowdoska-Curie fellowship PICSSAR Grant Number 624543. Used resources of NERSC.

  5. [The framing effect: medical implications].

    Science.gov (United States)

    Mazzocco, Ketti; Cherubini, Paolo; Rumiati, Rino

    2005-01-01

    Over the last 20 years, many studies explored how the way information is presented modifies choices. This sort of effect, referred to as "framing effects", typically consists of the inversion of choices when presenting structurally identical decision problems in different ways. It is a common assumption that physicians are unaffected (or less affected) by the surface description of a decision problem, because they are formally trained in medical decision making. However, several studies showed that framing effects occur even in the medical field. The complexity and variability of these effects are remarkable, making it necessary to distinguish among different framing effects, depending on whether the effect is obtained by modifying adjectives (attribute framing), goals of a behavior (goal framing), or the probability of an outcome (risky choice framing). A further reason for the high variability of the framing effects seems to be the domain of the decision problem, with different effects occurring in prevention decisions, disease-detection decisions, and treatment decisions. The present work reviews the studies on framing effects, in order to summarize them and clarify their possible role in medical decision making.

  6. Influence of initial velocity on trajectories of a charged particle in uniform crossed electric and magnetic fields

    International Nuclear Information System (INIS)

    Khotimah, Siti Nurul; Viridi, Sparisoma; Widayani

    2017-01-01

    Magnetic and electric fields can cause a charged particle to form interesting trajectories. In general, each trajectory is discussed separately in university physics textbooks for undergraduate students. In this work, a solution of a charged particle moving in a uniform electric field at right angles to a uniform magnetic field (uniform crossed electric and magnetic fields) is reported; it is limited to particle motion in a plane. Specific solutions and their trajectories are obtained only by varying the initial particle velocity. The result shows five basic trajectory patterns, i.e., straight line, sinusoid-like, cycloid, cycloid-like with oscillation, and circle-like. The region of each trajectory is also mapped in the initial velocity space of the particle. This paper is intended for undergraduate students and describes further the trajectories of a charged particle through the regions of electric and magnetic fields influenced by initial condition of the particle, where electromagnetic radiation of an accelerated particle is not considered. (paper)

  7. Who's been framed? Framing effects are reduced in financial gambles made for others.

    Science.gov (United States)

    Ziegler, Fenja V; Tunney, Richard J

    2015-01-01

    Decisions made on behalf of other people are sometimes more rational than those made for oneself. In this study we used a monetary gambling task to ask if the framing effect in decision-making is reduced in surrogate decision-making. Participants made a series of choices between a predetermined sure option and a risky gambling option of winning a proportion of an initial stake. Trials were presented as either a gain or a loss relative to that initial stake. In half of the trials participants made choices to earn money for themselves and in the other half they earned money for another participant. Framing effects were measured as risk seeking in loss frames and risk aversion in gain frames. Significant framing effects were observed both in trials in which participants earned money for themselves and those in which they earned money for another person; however, these framing effects were significantly reduced when making decisions for another person. It appears that the reduced emotional involvement when the decision-maker is not affected by the outcome of the decision thus lessens the framing effect without eradicating it altogether. This suggests that the deviation from rational choices in decision-making can be significantly reduced when the emotional impact on the decision maker is lessened. These results are discussed in relation to Somatic Distortion Theory.

  8. Uniformly Processed Strong Motion Database for Himalaya and Northeast Region of India

    Science.gov (United States)

    Gupta, I. D.

    2018-03-01

    This paper presents the first uniformly processed comprehensive database on strong motion acceleration records for the extensive regions of western Himalaya, northeast India, and the alluvial plains juxtaposing the Himalaya. This includes 146 three components of old analog records corrected for the instrument response and baseline distortions and 471 three components of recent digital records corrected for baseline errors. The paper first provides a background of the evolution of strong motion data in India and the seismotectonics of the areas of recording, then describes the details of the recording stations and the contributing earthquakes, which is finally followed by the methodology used to obtain baseline corrected data in a uniform and consistent manner. Two different schemes in common use for baseline correction are based on the application of the Ormsby filter without zero pads (Trifunac 1971) and that on the Butterworth filter with zero pads at the start as well as at the end (Converse and Brady 1992). To integrate the advantages of both the schemes, Ormsby filter with zero pads at the start only is used in the present study. A large number of typical example results are presented to illustrate that the methodology adopted is able to provide realistic velocity and displacement records with much smaller number of zero pads. The present strong motion database of corrected acceleration records will be useful for analyzing the ground motion characteristics of engineering importance, developing prediction equations for various strong motion parameters, and calibrating the seismological source model approach for ground motion simulation for seismically active and risk prone areas of India.

  9. On the coupling of fields and particles in accelerator and plasma physics

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2016-10-01

    In accelerator and plasma physics it is generally accepted that there is no need to solve the dynamical equations for particles motion in manifestly covariant form, that is by using the coordinate-independent proper time to parameterize particle world-lines in space-time. In other words, in order to describe the dynamical processes in the laboratory frame there is no need to use the laws of relativistic kinematics. It is sufficient to take into account the relativistic dependence of the particles momentum on the velocity in the second Newton's law. Therefore, the coupling of fields and particles is based, on the one hand, on the use of result from particle dynamics treated according to Newton's laws in terms of the relativistic three-momentum and, on the other hand, on the use of Maxwell's equations in standard form. In previous papers we argued that this is a misconception. The purpose of this paper is to describe in detail how to calculate the coupling between fields and particles in a correct way and how to develop a new algorithm for a particle tracking code in agreement with the use of Maxwell's equations in their standard form. Advanced textbooks on classical electrodynamics correctly tell us that Maxwell's equations in standard form in the laboratory frame and charged particles are coupled by introducing particles trajectories as projections of particles world-lines onto coordinates of the laboratory frame and by subsequently using the laboratory time to parameterize the trajectory curves. For the first time we showed a difference between conventional and covariant particle tracking results in the laboratory frame. This essential point has never received attention in the physical community. Only the solution of the dynamical equations in covariant form gives the correct coupling between field equations in standard form and particles trajectories in the laboratory frame. We conclude that previous theoretical and simulation results in accelerator and plasma

  10. On the coupling of fields and particles in accelerator and plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-10-15

    In accelerator and plasma physics it is generally accepted that there is no need to solve the dynamical equations for particles motion in manifestly covariant form, that is by using the coordinate-independent proper time to parameterize particle world-lines in space-time. In other words, in order to describe the dynamical processes in the laboratory frame there is no need to use the laws of relativistic kinematics. It is sufficient to take into account the relativistic dependence of the particles momentum on the velocity in the second Newton's law. Therefore, the coupling of fields and particles is based, on the one hand, on the use of result from particle dynamics treated according to Newton's laws in terms of the relativistic three-momentum and, on the other hand, on the use of Maxwell's equations in standard form. In previous papers we argued that this is a misconception. The purpose of this paper is to describe in detail how to calculate the coupling between fields and particles in a correct way and how to develop a new algorithm for a particle tracking code in agreement with the use of Maxwell's equations in their standard form. Advanced textbooks on classical electrodynamics correctly tell us that Maxwell's equations in standard form in the laboratory frame and charged particles are coupled by introducing particles trajectories as projections of particles world-lines onto coordinates of the laboratory frame and by subsequently using the laboratory time to parameterize the trajectory curves. For the first time we showed a difference between conventional and covariant particle tracking results in the laboratory frame. This essential point has never received attention in the physical community. Only the solution of the dynamical equations in covariant form gives the correct coupling between field equations in standard form and particles trajectories in the laboratory frame. We conclude that previous theoretical and simulation results in

  11. Effect of non-uniform surface resistance on the quality factor of superconducting niobium cavity

    Science.gov (United States)

    Tan, Weiwei; Lu, Xiangyang; Yang, Ziqin; Zhao, Jifei; Yang, Deyu; Yang, Yujia

    2016-08-01

    The formula Rs = G /Q0 is commonly used in the calculation of the surface resistance of radio frequency niobium superconducting cavities. The applying of such equation is under the assumption that surface resistance is consistent over the cavity. However, the distribution of the magnetic field varies over the cavity. The magnetic field in the equator is much higher than that in the iris. According to Thermal Feedback Theory, it leads non-uniform distribution of the density of heat flux, which results in a different temperature distribution along the cavity inter surface. The BCS surface resistance, which depends largely on the temperature, is different in each local inner surface. In this paper, the effect of surface non-uniform resistance on the quality factor has been studied, through the calculation of Q0 in the original definition of it. The results show that it is necessary to consider the non-uniform distribution of magnetic field when the accelerating field is above 20 MV/m for TESLA cavities. Also, the effect of inhomogeneity of residual resistance on the quality factor is discussed. Its distribution barely affects the quality factor.

  12. Framing scales and scaling frames

    NARCIS (Netherlands)

    van Lieshout, M.; Dewulf, A.; Aarts, N.; Termeer, K.

    2009-01-01

    Policy problems are not just out there. Actors highlight different aspects of a situation as problematic and situate the problem on different scales. In this study we will analyse the way actors apply scales in their talk (or texts) to frame the complex decision-making process of the establishment

  13. Exact analytic expressions for the evolution of polarization for radiation propagating in a plasma with non uniformly sheared magnetic field

    International Nuclear Information System (INIS)

    Segre, S. E.

    2001-01-01

    The known analytic expressions for the evolution of the polarization of electromagnetic waves propagating in a plasma with uniformly sheared magnetic field are extended to the case where the shear is not constant. Exact analytic expressions are found for the case when the space variations of the medium are such that the magnetic field components and the plasma density satisfy a particular condition (eq. 13), possibly in a convenient reference frame of polarization space [it

  14. Position-dependent energy-level shifts of an accelerated atom in the presence of a boundary

    International Nuclear Information System (INIS)

    Zhu Zhiying; Yu Hongwei

    2010-01-01

    We consider a uniformly accelerated atom interacting with a vacuum electromagnetic field in the presence of an infinite conducting plane boundary and calculate separately the contributions of vacuum fluctuations and radiation reaction to the atomic energy-level shift. We analyze in detail the behavior of the total energy shift in three different regimes of the distance in both the low-acceleration and high-acceleration limits. Our results show that, in general, an accelerated atom does not behave as if immersed in a thermal bath at the Unruh temperature in terms of the atomic energy-level shifts, and the effect of the acceleration on the atomic energy-level shifts may in principle become appreciable in certain circumstances, although it may not be realistic for actual experimental measurements. We also examine the effects of the acceleration on the level shifts when the acceleration is of the order of the transition frequency of the atom and we find some features which differ from what was obtained in the existing literature.

  15. C IV BROAD ABSORPTION LINE ACCELERATION IN SLOAN DIGITAL SKY SURVEY QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Grier, C. J.; Brandt, W. N.; Trump, J. R.; Schneider, D. P.; Sun, M.; Beatty, T. G. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Hall, P. B. [Department of Physics and Astronomy, York University, Toronto, ON M3J 1P3 (Canada); Filiz Ak, N. [Faculty of Sciences, Department of Astronomy and Space Sciences, Erciyes University, 38039 Kayseri (Turkey); Anderson, S. F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Green, Paul J. [Harvard Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Vivek, M.; Brownstein, Joel R. [Department of Physics and Astronomy, University of Utah, 115 S. 1400 E., Salt Lake City, UT 84112 (United States); Roman-Lopes, Alexandre, E-mail: grier@psu.edu [Departamento de Fisica, Facultad de Ciencias, Universidad de La Serena, Cisternas 1200, La Serena (Chile)

    2016-06-20

    We present results from the largest systematic investigation of broad absorption line (BAL) acceleration to date. We use spectra of 140 quasars from three Sloan Digital Sky Survey programs to search for global velocity offsets in BALs over timescales of ≈2.5–5.5 years in the quasar rest frame. We carefully select acceleration candidates by requiring monolithic velocity shifts over the entire BAL trough, avoiding BALs with velocity shifts that might be caused by profile variability. The C iv BALs of two quasars show velocity shifts consistent with the expected signatures of BAL acceleration, and the BAL of one quasar shows a velocity-shift signature of deceleration. In our two acceleration candidates, we see evidence that the magnitude of the acceleration is not constant over time; the magnitudes of the change in acceleration for both acceleration candidates are difficult to produce with a standard disk-wind model or via geometric projection effects. We measure upper limits to acceleration and deceleration for 76 additional BAL troughs and find that the majority of BALs are stable to within about 3% of their mean velocities. The lack of widespread acceleration/deceleration could indicate that the gas producing most BALs is located at large radii from the central black hole and/or is not currently strongly interacting with ambient material within the host galaxy along our line of sight.

  16. Approximately dual frames in Hilbert spaces and applications to Gabor frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Laugesen, Richard S.

    2011-01-01

    constructed via perturbation theory. An alternative bound is derived for the rich class of Gabor frames, by using the Walnut representation of the frame operator to estimate the deviation from equality in the duality conditions. To illustrate these results, we construct explicit approximate duals of Gabor...

  17. Accelerator-Driven Thorium Cycle: New Technology Makes It Feasible

    International Nuclear Information System (INIS)

    Adams, Marvin; Best, Fred; Kurwitz, Cable; McInturff, Al; McIntyre, Peter; Rogers, Bob; Sattarov, Akhdior; Wu Zeyun; Yavuz, Mustafa; Meitzler, Charles

    2002-01-01

    We have developed a conceptual design for an accelerator-driven thorium cycle power reactor which addresses the issues of accelerator performance, reliability, and neutronics that limited earlier designs. The proton drive beam is provided by a flux-coupled stack of isochronous cyclotrons, occupying the same footprint as a single cyclotron but providing 7 independent beams from 7 separate accelerating structures within a common magnetic envelope. The core is arranged in a hexagonal lattice, and the 7 beams are used to provide a hexagonal drive beam pattern so that the effective neutron gain is relatively uniform over the entire core volume. Reliability is achieved by redundancy: if any drive beam is interrupted, the other 6 suffice to maintain reactor operation. A new approach to fuel cladding should make it possible to operate with lead moderator at temperatures ∼ 800 C, enabling access to advanced heat cycles and perhaps to a Brayton cycle for hydrogen production. (authors)

  18. Frames in super Hilbert modules

    Directory of Open Access Journals (Sweden)

    Mehdi Rashidi-Kouchi

    2018-01-01

    Full Text Available In this paper, we define super Hilbert module and investigate frames in this space. Super Hilbert modules are  generalization of super Hilbert spaces in Hilbert C*-module setting. Also, we define frames in a super Hilbert module and characterize them by using of the concept of g-frames in a Hilbert C*-module. Finally, disjoint frames in Hilbert C*-modules are introduced and investigated.

  19. The Frame Game

    Science.gov (United States)

    Edwards, Michael Todd; Cox, Dana C.

    2011-01-01

    In this article, the authors explore framing, a non-multiplicative technique commonly employed by students as they construct similar shapes. When students frame, they add (or subtract) a "border" of fixed width about a geometric object. Although the approach does not yield similar shapes in general, the mathematical underpinnings of…

  20. Operator representations of frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Hasannasab, Marzieh

    2017-01-01

    of the properties of the operator T requires more work. For example it is a delicate issue to obtain a representation with a bounded operator, and the availability of such a representation not only depends on the frame considered as a set, but also on the chosen indexing. Using results from operator theory we show......The purpose of this paper is to consider representations of frames {fk}k∈I in a Hilbert space ℋ of the form {fk}k∈I = {Tkf0}k∈I for a linear operator T; here the index set I is either ℤ or ℒ0. While a representation of this form is available under weak conditions on the frame, the analysis...... that by embedding the Hilbert space ℋ into a larger Hilbert space, we can always represent a frame via iterations of a bounded operator, composed with the orthogonal projection onto ℋ. The paper closes with a discussion of an open problem concerning representations of Gabor frames via iterations of a bounded...

  1. Optimal primitive reference frames

    International Nuclear Information System (INIS)

    Jennings, David

    2011-01-01

    We consider the smallest possible directional reference frames allowed and determine the best one can ever do in preserving quantum information in various scenarios. We find that for the preservation of a single spin state, two orthogonal spins are optimal primitive reference frames; and in a product state, they do approximately 22% as well as an infinite-sized classical frame. By adding a small amount of entanglement to the reference frame, this can be raised to 2(2/3) 5 =26%. Under the different criterion of entanglement preservation, a very similar optimal reference frame is found; however, this time it is for spins aligned at an optimal angle of 87 deg. In this case 24% of the negativity is preserved. The classical limit is considered numerically, and indicates under the criterion of entanglement preservation, that 90 deg. is selected out nonmonotonically, with a peak optimal angle of 96.5 deg. for L=3 spins.

  2. Synthetic approaches to uniform polymers.

    Science.gov (United States)

    Ali, Monzur; Brocchini, Steve

    2006-12-30

    Uniform polymers are characterised by a narrow molecular weight distribution (MWD). Uniformity is also defined by chemical structure in respect of (1) monomer orientation, sequence and stereo-regularity, (2) polymer shape and morphology and (3) chemical functionality. The function of natural polymers such as polypeptides and polynucleotides is related to their conformational structure (e.g. folded tertiary structure). This is only possible because of their high degree of uniformity. While completely uniform synthetic polymers are rare, polymers with broad structure and MWD are widely used in medicine and the biomedical sciences. They are integral components in final dosage forms, drug delivery systems (DDS) and in implantable devices. Increasingly uniform polymers are being used to develop more complex medicines (e.g. delivery of biopharmaceuticals, enhanced formulations or DDS's for existing actives). In addition to the function imparted by any new polymer it will be required to meet stringent specifications in terms of cost containment, scalability, biocompatibility and performance. Synthetic polymers with therapeutic activity are also being developed to exploit their polyvalent properties, which is not possible with low molecular weight molecules. There is need to utilise uniform polymers for applications where the polymer may interact with the systemic circulation, tissues or cellular environment. There are also potential applications (e.g. stimuli responsive coatings) where uniform polymers may be used for their more defined property profile. While it is not yet practical to prepare synthetic polymers to the same high degree of uniformity as proteins, nature also effectively utilises many polymers with lower degrees of uniformity (e.g. polysaccharides, poly(amino acids), polyhydroxyalkanoates). In recent years it has become possible to prepare with practical experimental protocols sufficient quantities of polymers that display many aspects of uniformity. This

  3. Elasto-plastic frame under horizontal and vertical Gaussian excitation

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Tarp-Johansen, Niels Jacob; Randrup-Thomsen, S.

    1999-01-01

    Taking geometric non-linearity into account anoscillator of the form as aportal frame with a rigid traverse and with ideal-elastic ideal-plasticclamped-in columns behaves under horizontalexcitation as an ideal-elastic hardening / softening-plastic oscilator given that the columns carry atension....../compression axial force. Assuming that the horizontal excitationof the traverse is Gaussian white noise, statistics related to the plastic displacement response are determinedby use of simulation based on the Slepian modelprocess method combined with envelope excursion properties. Besidesgiving physical insight...... the method givesgood approximations to results obtained by slow direct simulation of thetotal response. Moreover, the influence of a randomly varying axial column force isinvestigated by direct response simulation. This case corresponds to parametric excitation as generated by the vertical acceleration...

  4. A homogeneous static gravitational field and the principle of equivalence

    International Nuclear Information System (INIS)

    Chernikov, N.A.

    2001-01-01

    In this paper any gravitational field (both in the Einsteinian case and in the Newtonian case) is described by the connection, called gravitational. A homogeneous static gravitational field is considered in the four-dimensional area z>0 of a space-time with Cartesian coordinates x, y, z, and t. Such field can be created by masses, disposed outside the area z>0 with a density distribution independent of x, y, and t. Remarkably, in the four-dimensional area z>0, together with the primitive background connection, the primitive gravitational connection has been derived. In concordance with the Principle of Equivalence all components of such gravitational connection are equal to zero in the uniformly accelerated frame system, in which the gravitational force of attraction is balanced by the inertial force. However, all components of such background connection are equal to zero in the resting frame system, but not in the accelerated frame system

  5. Seismic performance of existing R.C. framed buildings

    Directory of Open Access Journals (Sweden)

    Sameh A. El-Betar

    2017-08-01

    Full Text Available The earthquakes disasters basically occur due to buildings damage not because of the earth shaking. Therefore, the countries have being updated the seismic codes. The seismic loads for buildings design in Egyptian Code have been changed from (EC-1994 to (ECP-201, 2012. On the other hand, the need is raised to study the vulnerability of existing buildings, which can be divided into the buildings designed to resist the gravity loads only (GLD and the buildings designed according to Egyptian code (EC-1994. Comparison between forces due to Egyptian code for loads (EC-1994 and (ECP-201, 2012 is carried out on the multi-stories R.C. framed buildings which are the most common type of existing buildings in Egypt. To investigate the vulnerability of existing buildings, nonlinear static pushover analysis is conducted to evaluate the real strength of the existing buildings. Moreover, it is considered a useful and effective tool for the performance of three framed buildings: 3, 6 and 10 stories due to expected future earthquakes. Finally, it is found that the vulnerability of existing GLD buildings occurs at expected ground accelerations (ag greater than 0.125 g in Egyptian seismic map, while the EC-94 designed buildings behave elastically up to (ag equals to 0.2 g and above that a slight damage may occur.

  6. Body acceleration distribution and O2 uptake in humans during running and jumping

    Science.gov (United States)

    Bhattacharya, A.; Mccutcheon, E. P.; Shvartz, E.; Greenleaf, J. E.

    1980-01-01

    The distribution of body acceleration and associated oxygen uptake and heart rate responses are investigated in treadmill running and trampoline jumping. Accelerations in the +Gz direction were measured at the lateral ankle, lumbosacral region and forehead of eight young men during level treadmill walking and running at four speeds and trampoline jumping at four heights, together with corresponding oxygen uptake and heart rate. With increasing treadmill speed, peak acceleration at the ankle is found always to exceed that at the back and forehead, and acceleration profiles with higher frequency components than those observed during jumping are observed. Acceleration levels are found to be more uniformly distributed with increasing height in jumping, although comparable oxygen uptake and heat rates are obtained. Results indicate that the magnitude of the biomechanical stimuli is greater in trampoline jumping than in running, which finding could be of use in the design of procedures to avert deconditioning in persons exposed to weightlessness.

  7. Normalization of Gravitational Acceleration Models

    Science.gov (United States)

    Eckman, Randy A.; Brown, Aaron J.; Adamo, Daniel R.

    2011-01-01

    Unlike the uniform density spherical shell approximations of Newton, the con- sequence of spaceflight in the real universe is that gravitational fields are sensitive to the nonsphericity of their generating central bodies. The gravitational potential of a nonspherical central body is typically resolved using spherical harmonic approximations. However, attempting to directly calculate the spherical harmonic approximations results in at least two singularities which must be removed in order to generalize the method and solve for any possible orbit, including polar orbits. Three unique algorithms have been developed to eliminate these singularities by Samuel Pines [1], Bill Lear [2], and Robert Gottlieb [3]. This paper documents the methodical normalization of two1 of the three known formulations for singularity-free gravitational acceleration (namely, the Lear [2] and Gottlieb [3] algorithms) and formulates a general method for defining normalization parameters used to generate normalized Legendre Polynomials and ALFs for any algorithm. A treatment of the conventional formulation of the gravitational potential and acceleration is also provided, in addition to a brief overview of the philosophical differences between the three known singularity-free algorithms.

  8. Identifying issue frames in text.

    Directory of Open Access Journals (Sweden)

    Eyal Sagi

    Full Text Available Framing, the effect of context on cognitive processes, is a prominent topic of research in psychology and public opinion research. Research on framing has traditionally relied on controlled experiments and manually annotated document collections. In this paper we present a method that allows for quantifying the relative strengths of competing linguistic frames based on corpus analysis. This method requires little human intervention and can therefore be efficiently applied to large bodies of text. We demonstrate its effectiveness by tracking changes in the framing of terror over time and comparing the framing of abortion by Democrats and Republicans in the U.S.

  9. Vertical and horizontal test results of 3.9-GHz accelerating cavities at FNAL

    Energy Technology Data Exchange (ETDEWEB)

    Khabiboulline, T.; Edwards, H.; Foley, M.; Harms, E.; Hocker, James Andrew; Mitchell, D.; Rowe, A.; Solyak, N.; /Fermilab

    2008-06-01

    The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve the beam performance of the VUV FEL, FLASH. In the frame of a collaborative agreement, Fermilab will provide DESY with a cryomodule containing a string of four cavities. Seven 9-cell Nb cavities were tested and six of them did reach accelerating gradient up to 24 MV/m almost twice more than design value of 14 MV/m. Two of these cavities are with new HOM couplers with improved design. In this paper we present all results of the vertical and horizontal tests.

  10. Physics design of heavy-ion irradiation beam line on HI-13 tandem accelerator

    International Nuclear Information System (INIS)

    Zhu Fei; Peng Zhaohua; Hu Yueming; Jiao Xuesheng; Chen Dongfeng; Cao Yali

    2014-01-01

    Background: Heavy-ion microporous membrane is a new kind of filter material, which has prosperous application in the fields of medical and biological agents, electronic, food, environmental science, materials science, etc. Purpose: Polyester membranes were irradiated with 32 S produced by HI-13 tandem accelerator to develop a microporous membrane at CIAE, and the irradiation uniformity is determined by the beam distribution, also the microporous uniformity is required higher than 90%. Methods: An octupole magnet was used to correct the beam distribution from Gauss to uniform. Meanwhile, main parameters of beam line were given, and the alignment tolerances for optical elements were also analyzed. Results: Alignment tolerance of the optical elements could cause great influence on the beam center deviation in the process of correction, which would destroy the irradiation uniformity. Steering magnet was applied to meet with the design requirements. Conclusion: This study provides a practical and feasible way for industrial production of heavy-ion microporous membrane. (authors)

  11. Characterization of Oblique Dual Frame Pairs

    DEFF Research Database (Denmark)

    Christensen, Ole; Eldar, Yonina

    2006-01-01

    Given a frame for a subspace W of a Hilbert space H, we consider all possible families of oblique dual frame vectors on an appropriately chosen subspace V. In place of the standard description, which involves computing the pseudoinverse of the frame operator, we develop an alternative characteriz...... for the case of shift-invariant spaces with a single generator. The theory is also adapted to the standard frame setting in which the original and dual frames are defined on the same space. Copyright (C) 2006 Hindawi Publishing Corporation. All rights reserved.......Given a frame for a subspace W of a Hilbert space H, we consider all possible families of oblique dual frame vectors on an appropriately chosen subspace V. In place of the standard description, which involves computing the pseudoinverse of the frame operator, we develop an alternative...

  12. New Developments in the Simulation of Advanced Accelerator Concepts

    International Nuclear Information System (INIS)

    Paul, K.; Cary, J.R.; Cowan, B.; Bruhwiler, D.L.; Geddes, C.G.R.; Mullowney, P.J.; Messmer, P.; Esarey, E.; Cormier-Michel, E.; Leemans, W.P.; Vay, J.-L.

    2008-01-01

    Improved computational methods are essential to the diverse and rapidly developing field of advanced accelerator concepts. We present an overview of some computational algorithms for laser-plasma concepts and high-brightness photocathode electron sources. In particular, we discuss algorithms for reduced laser-plasma models that can be orders of magnitude faster than their higher-fidelity counterparts, as well as important on-going efforts to include relevant additional physics that has been previously neglected. As an example of the former, we present 2D laser wakefield accelerator simulations in an optimal Lorentz frame, demonstrating and gt;10 GeV energy gain of externally injected electrons over a 2 m interaction length, showing good agreement with predictions from scaled simulations and theory, with a speedup factor of ∼2,000 as compared to standard particle-in-cell.

  13. Framing Autism: A Content Analysis of Five Major News Frames in U.S.-Based Newspapers.

    Science.gov (United States)

    Wendorf Muhamad, Jessica; Yang, Fan

    2017-03-01

    The portrayal of child autism-related news stories has become a serious issue in the United States, yet few studies address this from media framing perspective. To fill this gap in the literature, this study examined the applicability of a media framing scale (Semetko & Valkenburg, 2000) for the deductive examination of autism-related news stories in U.S.-based newspapers. Under the theoretical framework of framing theory, a content analysis of news stories (N = 413) was conducted to investigate the presence of the five news frames using an established questionnaire. Differentiating between local and national news outlets, the following five news frames were measured: (a) attribution of responsibility, (b) human interest, (c) conflict, (d) morality, and (e) economic consequences. Findings revealed that news stories about autism most frequently fell within the human interest frame. Furthermore, the study shed light on how local and national newspapers might differ in framing autism-related news pieces and in their placement of the autism-related story within the newspaper (e.g., front page section, community section).

  14. Framing Effects: Dynamics and Task Domains

    Science.gov (United States)

    Wang

    1996-11-01

    The author examines the mechanisms and dynamics of framing effects in risky choices across three distinct task domains (i.e., life-death, public property, and personal money). The choice outcomes of the problems presented in each of the three task domains had a binary structure of a sure thing vs a gamble of equal expected value; the outcomes differed in their framing conditions and the expected values, raging from 6000, 600, 60, to 6, numerically. It was hypothesized that subjects would become more risk seeking, if the sure outcome was below their aspiration level (the minimum requirement). As predicted, more subjects preferred the gamble when facing the life-death choice problems than facing the counterpart problems presented in the other two task domains. Subjects' risk preference varied categorically along the group size dimension in the life-death domain but changed more linearly over the expected value dimension in the monetary domain. Framing effects were observed in 7 of 13 pairs of problems, showing a positive frame-risk aversion and negative frame-risk seeking relationship. In addition, two types of framing effects were theoretically defined and empirically identified. A bidirectional framing effect involves a reversal in risk preference, and occurs when a decision maker's risk preference is ambiguous or weak. Four bidirectional effects were observed; in each case a majority of subjects preferred the sure outcome under a positive frame but the gamble under a negative frame. In contrast, a unidirectional framing effect refers to a preference shift due to the framing of choice outcomes: A majority of subjects preferred one choice outcome (either the sure thing or the gamble) under both framing conditions, with positive frame augmented the preference for the sure thing and negative frame augmented the preference for the gamble. These findings revealed some dynamic regularities of framing effects and posed implications for developing predictive and testable

  15. Ambiguities in the deduction of rest frame fluctuation spectrums from spectrums computed in moving frames

    International Nuclear Information System (INIS)

    Fredericks, R.W.; Coroniti, F.V.

    1976-01-01

    The problem of interpretation of power spectrums computed by Fourier analysis of data time series taken in frames moving with respect to the medium containing the fluctuations is examined. It is found that no unique connection exists between the rest frame power spectrum as a function of scale length and the derived power spectrum as a function 'frequency' computed from the time series data taken in the moving frame. This caused by a complex Doppler-shifting phenomenon that leads to a basically aliased frequency spectrum in the moving frame. Examples of nonuniqueness are given for various types of rest frame density or wave turbulence that lead to the same frequency dependence of the power spectrum computed in the moving frame. This has implications for the past interpretations of power spectrums of density or magnetic field fluctuations from satellites or interplanetary probes

  16. Predicting the Strength of Online News Frames

    Directory of Open Access Journals (Sweden)

    Hrvoje Jakopović

    2017-10-01

    Full Text Available Framing theory is one of the most significant approaches to understanding media and their potential impact on publics. Leaving aside that fact, the author finds that publicity effects seem to be dispersed and difficult to catch for public relations. This article employs a specific research design, which could be applied to public relations practice, namely with a view to observing correlations between specific media frames and individual frames. The approach is based on the typology of news frames. The author attributes negative, positive and neutral determinants to the types of frames in his empirical research. Online news regarding three transport organizations and the accompanying user comments (identified as negative, positive and neutral are analysed by means of the method of content and sentiment analysis. The author recognizes user comments and reviews as individual frames that take part in the creation of online image. Furthermore, he identifies the types of media frames as well as individual frames manifested as image, and undertakes correlation research in order to establish their prediction potential. The results expose the most frequently used types of media frames concerning the transport domain. The media are keen to report through the attribution of responsibility frame, and after that, through the economic frame and the conflict frame, but, on the other hand, they tend to neglect the human interest frame and the morality frame. The results show that specific types of news frames enable better prediction of user reactions. The economic frame and the human interest frame therefore represent the most predictable types of frame.

  17. Framing and Claiming: How Information-Framing Affects Expected Social Security Claiming Behavior.

    Science.gov (United States)

    Brown, Jeffrey R; Kapteyn, Arie; Mitchell, Olivia S

    2016-03-01

    This paper provides evidence that Social Security benefit claiming decisions are strongly affected by framing and are thus inconsistent with expected utility theory. Using a randomized experiment that controls for both observable and unobservable differences across individuals, we find that the use of a "breakeven analysis" encourages early claiming. Respondents are more likely to delay when later claiming is framed as a gain, and the claiming age is anchored at older ages. Additionally, the financially less literate, individuals with credit card debt, and those with lower earnings are more influenced by framing than others.

  18. Applications of microprocessors in upgrading of accelerator controls

    International Nuclear Information System (INIS)

    Mallory, K.B.

    1977-03-01

    Experience at SLAC demonstrates that the criteria for selection and use of microprocessors in modifying an existing control system may differ from the criteria that apply during installation of the control system of a new accelerator. Considerations such as cost of individual projects, progressive installation without disruption of operations and training of on-board personnel can outweigh ''obvious'' goals such as standardization of hardware, uniformity of software, or even a rigid specification of link protocols with the main computer system

  19. Strategic Framing Study Circles: Toward a Gold Standard of Framing Pedagogy

    Science.gov (United States)

    Feinberg, Jane

    2009-01-01

    This article explains how communities of practice have been developed as part of FrameWorks' field-building efforts. Strategic Framing Study Circles, as they are known, have been conducted with four statewide coalitions, one group of national organizations, and an emerging regional coalition. The goal of each community of practice is to build…

  20. Specific contributions of the Dutch progamme ''RAS'' towards accelerator-based transmutation

    International Nuclear Information System (INIS)

    Abrahams, K.; Franken, W.M.P.; Bultman, J.H.; Heil, J.A.; Koning, A.J.

    1994-09-01

    Accelerator-based transmutation is being studied by ECN within its general nuclear waste transmutation programme RAS. In this paper the following contributions are presented: (1) Evaluation of cross sections at intermediate energies, within an international frame given by NEA, (2) Cell calculations on the equilibration of transuranium actinides in thermal molten-salt transmuters, (3) Irradiation facilities at the European research reactor HFR in Petten, which have been constructed with the purpose to demonstrate and investigate the transmutation of waste in a high neutron flux, (4) Studies of accelerator-based neutron generating systems to transmute neptunium and technetium, (5) Comparison of several systems on the basis of criteria for successful nuclear waste-management. (orig.)

  1. Compliance Framing - Framing Compliance

    OpenAIRE

    Lutz-Ulrich Haack; Martin C. Reimann

    2012-01-01

    Corporations have to install various organizational measures to comply with legal as well as internal guidelines systematically. Compliance management systems have the challenging task to make use of an internal compliance-marketing approach in order to ensure not only an adequate but also effective compliance-culture. Compliance-literature and findings of persuasive goal-framing-theory give opposite implications for establishing a rather values- versus rule-based compliance-culture respectiv...

  2. Characterization of Oblique Dual Frame Pairs

    Directory of Open Access Journals (Sweden)

    Christensen Ole

    2006-01-01

    Full Text Available Given a frame for a subspace of a Hilbert space , we consider all possible families of oblique dual frame vectors on an appropriately chosen subspace . In place of the standard description, which involves computing the pseudoinverse of the frame operator, we develop an alternative characterization which in some cases can be computationally more efficient. We first treat the case of a general frame on an arbitrary Hilbert space, and then specialize the results to shift-invariant frames with multiple generators. In particular, we present explicit versions of our general conditions for the case of shift-invariant spaces with a single generator. The theory is also adapted to the standard frame setting in which the original and dual frames are defined on the same space.

  3. Beam halo formation from space-charge dominated beams in uniform focusing channels

    International Nuclear Information System (INIS)

    O'Connell, J.S.; Wangler, T.P.; Mills, R.S.; Crandall, K.R.

    1993-01-01

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which results in a 2-component beam consisting of an inner core and an outer halo. The halo is very prominent in mismatched beams, and the potential for accelerator activation is of concern for a next generation of cw, high-power proton linacs that could be applied for intense neutron generators to process nuclear materials. We present new results about beam halo and the evolution of space-charge dominated beams from multiparticle simulation of initial laminar beams in a uniform linear focusing channel, and from a model consisting of single particle interactions with a uniform-density beam core. We study the energy gain from particle interactions with the space-charge field of the core, and we identify the resonant characteristic of this interaction as the basic cause of the separation of the beam into the two components. We identify three different particle-trajectory types, and we suggest that one of these types may lead to continuous halo growth, even after the halo is removed by collimators

  4. Prospects for 10T accelerator dipole magnets

    International Nuclear Information System (INIS)

    Taylor, C.E.; Meuser, R.B.

    1981-03-01

    A next-generation major accelerator will require the highest possible field to minimize the circumference; however, there have been no proven designs for suitable magnets with fields substantially higher than 5T. A number of successful 4 to 5T dipole magnets have been built in recent years; these have involved long and difficult development projects. The 3'' bore 4.25T magnets for the Doubler are being produced by the hundreds at Fermilab, and a number of prototypes of the 5.2'' bore 5T ISABELLE magnets have been built. Successful short, approx. 5T models have been made at SACLAY, KEK, and Serpukhov, and a number of model magnets with lower fields have been built at many laboratories. Field uniformity achieved in these magnets is about ΔB/B approx. = 10 -3 . 10T magnets with higher field uniformity will be a challenging development task. The general problems of high-field (10T) magnets are discussed in terms of superconductor performance and mechanical limitations

  5. Simple Design Tool for Development of Well Insulated Window Frames and Optimization of the Frame Geometry

    DEFF Research Database (Denmark)

    Zajas, Jan Jakub; Heiselberg, Per

    2012-01-01

    in order to approach an optimal solution. The program was also used to conduct an optimization process of the frame geometry. A large number of various window frame designs were created and evaluated, based on their insulation properties. The paper presents the investigation process and some of the best......This paper describes a design tool created with the purpose of designing highly insulated window frames. The design tool is based on a parametric model of the frame geometry, where various parameters describing the frame can be easily changed by the user. Based on this input, geometry of the frame...... is generated by the program and is used by the finite element simulator to calculate the thermal performance of the frame (the U value). After the initial design is evaluated, the user can quickly modify chosen parameters and generate a new design. This process can then be repeated in multiple iterations...

  6. Key Frame Extraction in the Summary Space.

    Science.gov (United States)

    Li, Xuelong; Zhao, Bin; Lu, Xiaoqiang; Xuelong Li; Bin Zhao; Xiaoqiang Lu; Lu, Xiaoqiang; Li, Xuelong; Zhao, Bin

    2018-06-01

    Key frame extraction is an efficient way to create the video summary which helps users obtain a quick comprehension of the video content. Generally, the key frames should be representative of the video content, meanwhile, diverse to reduce the redundancy. Based on the assumption that the video data are near a subspace of a high-dimensional space, a new approach, named as key frame extraction in the summary space, is proposed for key frame extraction in this paper. The proposed approach aims to find the representative frames of the video and filter out similar frames from the representative frame set. First of all, the video data are mapped to a high-dimensional space, named as summary space. Then, a new representation is learned for each frame by analyzing the intrinsic structure of the summary space. Specifically, the learned representation can reflect the representativeness of the frame, and is utilized to select representative frames. Next, the perceptual hash algorithm is employed to measure the similarity of representative frames. As a result, the key frame set is obtained after filtering out similar frames from the representative frame set. Finally, the video summary is constructed by assigning the key frames in temporal order. Additionally, the ground truth, created by filtering out similar frames from human-created summaries, is utilized to evaluate the quality of the video summary. Compared with several traditional approaches, the experimental results on 80 videos from two datasets indicate the superior performance of our approach.

  7. On the structures of Grassmannian frames

    OpenAIRE

    Haas IV, John I.; Casazza, Peter G.

    2017-01-01

    A common criterion in the design of finite Hilbert space frames is minimal coherence, as this leads to error reduction in various signal processing applications. Frames that achieve minimal coherence relative to all unit-norm frames are called Grassmannian frames, a class which includes the well-known equiangular tight frames. However, the notion of "coherence minimization" varies according to the constraints of the ambient optimization problem, so there are other types of "minimally coherent...

  8. Approximate Pressure Distribution in an Accelerating Launch-Vehicle Fuel Tank

    Science.gov (United States)

    Nemeth, Michael P.

    2010-01-01

    A detailed derivation of the equations governing the pressure in a generic liquid-fuel launch vehicle tank subjected to uniformly accelerated motion is presented. The equations obtained are then for the Space Shuttle Superlightweight Liquid-Oxygen Tank at approximately 70 seconds into flight. This generic derivation is applicable to any fuel tank in the form of a surface of revolution and should be useful in the design of future launch vehicles

  9. 46 CFR 310.11 - Cadet uniforms.

    Science.gov (United States)

    2010-10-01

    ... for State, Territorial or Regional Maritime Academies and Colleges § 310.11 Cadet uniforms. Cadet uniforms shall be supplied at the school in accordance with the uniform regulations of the School. Those... 46 Shipping 8 2010-10-01 2010-10-01 false Cadet uniforms. 310.11 Section 310.11 Shipping MARITIME...

  10. Qualitative models of magnetic field accelerated propagation in a plasma due to the Hall effect

    International Nuclear Information System (INIS)

    Kukushkin, A.B.; Cherepanov, K.V.

    2000-01-01

    Two qualitatively new models of accelerated magnetic field propagation (relative to normal diffusion) in a plasma due to the Hall effect are developed within the frames of the electron magnetic hydrodynamics. The first model is based on a simple hydrodynamic approach, which, in particular, reproduces the number of known theoretical results. The second one makes it possible to obtain exact analytical description of the basic characteristics of the magnetic field accelerated propagation in a inhomogeneous iso-thermic plasma, namely, the magnetic field front and its effective width [ru

  11. New avenues for framing research

    NARCIS (Netherlands)

    de Vreese, C.H.

    2012-01-01

    In this article, the author reviews the studies in this special issue of the American Behavioral Scientist. It is a strong collection of articles reporting findings from an integrated project that looks at frame building, frames, and effects of frames. The project is part of an exciting large-scale

  12. Six problems in frame theory

    DEFF Research Database (Denmark)

    Christensen, Ole

    2014-01-01

    We discuss various problems in frame theory that have been open for some years. A short discussion of frame theory is also provided, but it only contains the information that is necessary in order to understand the open problems and their role.......We discuss various problems in frame theory that have been open for some years. A short discussion of frame theory is also provided, but it only contains the information that is necessary in order to understand the open problems and their role....

  13. Should School Nurses Wear Uniforms?

    Science.gov (United States)

    Journal of School Health, 2001

    2001-01-01

    This 1958 paper questions whether school nurses should wear uniforms (specifically, white uniforms). It concludes that white uniforms are often associated with the treatment of ill people, and since many people have a fear reaction to them, they are not necessary and are even undesirable. Since school nurses are school staff members, they should…

  14. Framing (implicitly) matters

    DEFF Research Database (Denmark)

    Anderson, Joel; Antalikova, Radka

    2014-01-01

    Denmark is currently experiencing the highest immigration rate in its modern history. Population surveys indicate that negative public attitudes toward immigrants actually stem from attitudes toward their (perceived) Islamic affiliation. We used a framing paradigm to investigate the explicit...... and implicit attitudes of Christian and Atheist Danes toward targets framed as Muslims or as immigrants. The results showed that explicit and implicit attitudes were more negative when the target was framed as a Muslim, rather than as an immigrant. Interestingly, implicit attitudes were qualified...... by the participants’ religion. Specifically, analyses revealed that Christians demonstrated more negative implicit attitudes toward immigrants than Muslims. Conversely, Atheists demonstrated more negative implicit attitudes toward Muslims than Atheists. These results suggest a complex relationship between religion...

  15. MedlinePlus FAQ: Framing

    Science.gov (United States)

    ... URL of this page: https://medlineplus.gov/faq/framing.html I'd like to link to MedlinePlus, ... M. encyclopedia. Our license agreements do not permit framing of their content from our site. For more ...

  16. Framing and Claiming: How Information-Framing Affects Expected Social Security Claiming Behavior

    Science.gov (United States)

    Brown, Jeffrey R.; Kapteyn, Arie; Mitchell, Olivia S.

    2017-01-01

    This paper provides evidence that Social Security benefit claiming decisions are strongly affected by framing and are thus inconsistent with expected utility theory. Using a randomized experiment that controls for both observable and unobservable differences across individuals, we find that the use of a “breakeven analysis” encourages early claiming. Respondents are more likely to delay when later claiming is framed as a gain, and the claiming age is anchored at older ages. Additionally, the financially less literate, individuals with credit card debt, and those with lower earnings are more influenced by framing than others. PMID:28579641

  17. 28 CFR 570.21 - Time-frames.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Time-frames. 570.21 Section 570.21... PROGRAMS Pre-Release Community Confinement § 570.21 Time-frames. (a) Community confinement. Inmates may be... inmate's term of imprisonment or six months. (c) Exceeding time-frames. These time-frames may be exceeded...

  18. Frames, agency and institutional change

    DEFF Research Database (Denmark)

    Rasmussen, Grane Mikael Gregaard; Jensen, Per Langaa; Gottlieb, Stefan Christoffer

    2017-01-01

    This study examines change and the sources influencing the formulation and diffusion of policies in construction. The change examined is the introduction of a benchmarking policy initiative in the Danish construction industry. Using institutional theory with emphasis on the concepts of frames...... and framings, we show how strategically motivated actors are able to frame policy problems in ways that disclose the mixture of motives, interests and institutional mechanisms at play in change processes. In doing so, we contribute to the literature on the role of agency in institutional change and the framing...

  19. SEISMIC PERFORMANCE OF MOMENT-RESISTING CONCRETE FRAMES SUBJECTED TO EARTHQUAKE EXCITATION

    Directory of Open Access Journals (Sweden)

    FADZLI MOHAMED NAZRI

    2014-12-01

    Full Text Available In this study, moment-resisting concrete frames (MRCFs were designed based on Eurocodes 2 and 8, which indicate the seismic provisions and requirements for building design and construction. This study aims to investigate the damage measure of MRCFs subjected to earthquake excitation by pushover analysis (POA and incremental dynamic analysis (IDA. In POA, inverted triangular lateral load and uniform lateral load patterns were used to produce a base shear–drift curve. In IDA, seven far-field and seven near-field ground motion records were selected to establish the base shear–drift relationship. Structural response and damage measures were examined by the performance-based seismic design limit states. Vision 2000 proposed four performance states, namely, fully operational, operational, life safety (LS, and near collapse. The results showed that the designed structures have low stiffness because all MRCFs failed to meet the LS limit state. The base shear–drift relationship produced a higher demand in IDA than in POA. In POA, the lateral uniform load pattern produced higher demand than the lateral inverted triangular load pattern. In IDA, the farfield effect produced higher demand than the near-field effect. POA approximated IDA accurately at the elastic stage, but the approximation failed after the yield point.

  20. Seismic Performance Comparison of a High-Content SDA Frame and Standard RC Frame

    OpenAIRE

    van de Lindt, John W.; Rechan, R. Karthik

    2011-01-01

    This study presents the method and results of an experiment to study the seismic behavior of a concrete portal frame with fifty percent of its cement content replaced with a spray dryer ash (SDA). Based on multiple-shake-table tests, the high content SDA frame was found to perform as well as the standard concrete frame for two earthquakes exceeding design-level intensity earthquakes. Hence, from a purely seismic/structural standpoint, it may be possible to replace approximately fifty percen...

  1. Particle Acceleration, Magnetic Field Generation and Emission from Relativistic Jets

    Science.gov (United States)

    Nishikawa, K.-I.; Hardee, P.; Hededal, C.; Mizuno, Yosuke; Fishman, G. Jerry; Hartmann, D. H.

    2006-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), gamma-ray bursts (GRBs), supernova remnants, and Galactic microquasar systems usually have power-law emission spectra. Fermi acceleration is the mechanism usually assumed for the acceleration of particles in astrophysical environments. Recent PIC simulations using injected relativistic electron-ion (electro-positron) jets show that particle acceleration occurs within the downstream jet, rather than by the scattering of particles back and forth across the shock as in Fermi acceleration. Shock acceleration' is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different spectral properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants. We will review recent PIC simulations of relativistic jets and try to make a connection with observations.

  2. Neutrino oscillations in non-inertial frames and the violation of the equivalence principle neutrino mixing induced by the equivalence principle violation

    International Nuclear Information System (INIS)

    Lambiase, G.

    2001-01-01

    Neutrino oscillations are analyzed in an accelerating and rotating reference frame, assuming that the gravitational coupling of neutrinos is flavor dependent, which implies a violation of the equivalence principle. Unlike the usual studies in which a constant gravitational field is considered, such frames could represent a more suitable framework for testing if a breakdown of the equivalence principle occurs, due to the possibility to modulate the (simulated) gravitational field. The violation of the equivalence principle implies, for the case of a maximal gravitational mixing angle, the presence of an off-diagonal term in the mass matrix. The consequences on the evolution of flavor (mass) eigenstates of such a term are analyzed for solar (oscillations in the vacuum) and atmospheric neutrinos. We calculate the flavor oscillation probability in the non-inertial frame, which does depend on its angular velocity and linear acceleration, as well as on the energy of neutrinos, the mass-squared difference between two mass eigenstates, and on the measure of the degree of violation of the equivalence principle (Δγ). In particular, we find that the energy dependence disappears for vanishing mass-squared difference, unlike the result obtained by Gasperini, Halprin, Leung, and other physical mechanisms proposed as a viable explanation of neutrino oscillations. Estimations on the upper values of Δγ are inferred for a rotating observer (with vanishing linear acceleration) comoving with the earth, hence ω∝7.10 -5 rad/sec, and all other alternative mechanisms generating the oscillation phenomena have been neglected. In this case we find that the constraints on Δγ are given by Δγ≤10 2 for solar neutrinos and Δγ≤10 6 for atmospheric neutrinos. (orig.)

  3. Gain-Framed Messages Do Not Motivate Sun Protection: A Meta-Analytic Review of Randomized Trials Comparing Gain-Framed and Loss-Framed Appeals for Promoting Skin Cancer Prevention

    Science.gov (United States)

    O’Keefe, Daniel J.; Wu, Daisy

    2012-01-01

    Persuading people to undertake actions to prevent skin cancer is an important public health challenge. A number of studies have compared the effectiveness of gain-framed and loss-framed appeals in this domain, often expecting gain-framed appeals to be more persuasive. A meta-analytic review (k = 33, N = 4,168), however, finds no significant difference in the persuasiveness of gain- and loss-framed appeals for encouraging skin cancer prevention. This conclusion is unaffected by differences in the specific protective action advocated or by differences in the kind of outcomes invoked. But the results offer an intimation that men might be more susceptible to framing variations in this domain—with loss-framed appeals potentially having a persuasive advantage. PMID:22829794

  4. Frames, operator representations, and open problems

    DEFF Research Database (Denmark)

    Christensen, Ole; Hasannasab, Marzieh

    2018-01-01

    , a topic that has recently attracted considerably interest within harmonic analysis. The goal of the paper is twofold, namely, that experts in operator theory will explore the potential of frames, and that frame theory will benefit from insight provided by the operator theory community.......A frame in a Hilbert space H is a countable collection of elements in H that allows each f ϵ H to be expanded as an (infinite) linear combination of the frame elements. Frames generalize the wellknown orthonormal bases, but provide much more exibility and can often be constructed with properties...... that are not possible for orthonormal bases. We will present the basic facts in frame theory with focus on their operator theoretical characterizations and discuss open problems concerning representations of frames in terms of iterations of a fixed operator. These problems come up in the context of dynamical sampling...

  5. An introduction to finite tight frames

    CERN Document Server

    Waldron, Shayne F D

    2018-01-01

    This textbook is an introduction to the theory and applications of finite tight frames, an area that has developed rapidly in the last decade. Stimulating much of this growth are the applications of finite frames to diverse fields such as signal processing, quantum information theory, multivariate orthogonal polynomials, and remote sensing. Key features and topics: * First book entirely devoted to finite frames * Extensive exercises and MATLAB examples for classroom use * Important examples, such as harmonic and Heisenberg frames, are presented in preliminary chapters, encouraging readers to explore and develop an intuitive feeling for tight frames * Later chapters delve into general theory details and recent research results * Many illustrations showing the special aspects of the geometry of finite frames * Provides an overview of the field of finite tight frames * Discusses future research directions in the field Featuring exercises and MATLAB examples in each chapter, the book is well suited as a textbook ...

  6. Analisis Framing dalam Riset Public Relations

    Directory of Open Access Journals (Sweden)

    NARAYANA MAHENDRA PRASTYA

    2016-12-01

    Full Text Available This paper aims to give description about how to use frame analysis in Public Relations (PR research. The author use two framing models: Entman and Pan & Kosicki. The object is organization official statement about particular issue. Frame analysis method rarely used in Public Relations research. This methods commonly use in journalism study, to analyse the news in media. Meanwhile, the key word of framing is the social construction of reality. Organization can make social construction of realty in their official statement. In acacemic term, frame analysis in PR research is useful to know how organization positioned themselves in particular situation. Other benefit is use to evaluat whether the organization frame is conformable with the public opinion or agenda setting media or not. In practical term, frame analysis give benefit for PR practitioner to create the message that can be undserstood by public, also give positive image for organization.

  7. Framing and misperception in public good experiments

    DEFF Research Database (Denmark)

    Fosgaard, Toke Reinholt; Hansen, Lars Gårn; Wengström, Erik Roland

    2017-01-01

    Earlier studies have found that framing has substantial impact on the degree of cooperation observed in public good experiments. We show that the way the public good game is framed affects misperceptions about the incentives of the game. Moreover, we show that such framing-induced differences...... in misperceptions are linked to the framing effect on subjects' cooperation behavior. When we do not control for the different levels of misperceptions between frames, we observe a significant framing effect on subjects’ cooperation preferences. However, this framing effect becomes insignificant once we remove...

  8. All framing effects are not created equal: Low convergent validity between two classic measurements of framing.

    Science.gov (United States)

    Zhen, Shanshan; Yu, Rongjun

    2016-07-20

    Human risk-taking attitudes can be influenced by two logically equivalent but descriptively different frames, termed the framing effect. The classic hypothetical vignette-based task (Asian disease problem) and a recently developed reward-based gambling task have been widely used to assess individual differences in the framing effect. Previous studies treat framing bias as a stable trait that has genetic basis. However, these two paradigms differ in terms of task domain (loss vs. gain) and task context (vignette-based vs. reward-based) and the convergent validity of these measurements remains unknown. Here, we developed a vignette-based task and a gambling task in both gain and loss domains and tested correlations of the framing effect among these tasks in 159 young adults. Our results revealed no significant correlation between the vignette-based task in the loss domain and the gambling task in the gain domain, indicating low convergent validity. The current findings raise the question of how to measure the framing effect precisely, especially in individual difference studies using large samples and expensive neuroscience methods. Our results suggest that the framing effect is influenced by both task domain and task context and future research should be cautious about the operationalization of the framing effect.

  9. Radiation Field Forming for Industrial Electron Accelerators Using Rare-Earth Magnetic Materials

    Science.gov (United States)

    Ermakov, A. N.; Khankin, V. V.; Shvedunov, N. V.; Shvedunov, V. I.; Yurov, D. S.

    2016-09-01

    The article describes the radiation field forming system for industrial electron accelerators, which would have uniform distribution of linear charge density at the surface of an item being irradiated perpendicular to the direction of its motion. Its main element is non-linear quadrupole lens made with the use of rare-earth magnetic materials. The proposed system has a number of advantages over traditional beam scanning systems that use electromagnets, including easier product irradiation planning, lower instantaneous local dose rate, smaller size, lower cost. Provided are the calculation results for a 10 MeV industrial electron accelerator, as well as measurement results for current distribution in the prototype build based on calculations.

  10. Particle Acceleration, Magnetic Field Generation, and Emission in Relativistic Pair Jets

    Science.gov (United States)

    Nishikawa, K.-I.; Ramirez-Ruiz, E.; Hardee, P.; Hededal, C.; Mizuno, Y.

    2005-01-01

    Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created by relativistic pair jets are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet propagating through an ambient plasma with and without initial magnetic fields. The growth rates of the Weibel instability depends on the distribution of pair jets. Simulations show that the Weibel instability created in the collisionless shock accelerates particles perpendicular and parallel to the jet propagation direction. The simulation results show that this instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields, which contribute to the electron's transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  11. Electrical performance characteristics of the SSC Accelerator System String Test

    International Nuclear Information System (INIS)

    Robinson, W.; Burgett, W.; Dombeck, T.; Gannon, J.; Kraushaar, P.; McInturff, A.; Savord, T.; Tool, G.

    1993-01-01

    The string test facility was constructed to provide a development test bed for the arc regions of the Superconducting Super Collider (SSC). Significant effort has been devoted to the development and testing of superconducting magnets, spools, and accelerator control systems required for the SSC. The string test facility provides the necessary environment required to evaluate the operational performance of these components as they are configured as an accelerator lens in the collider. This discussion will review the results of high current testing of the string conducted to evaluate magnet element uniformity and compatibility, the splice resistance used to connect the magnets, and system response to various quench conditions. Performance results of the spools, energy bypass systems, energy dump, and the power supply system are also discussed

  12. Electrical performance characteristics of the SSC Accelerator System String Test

    International Nuclear Information System (INIS)

    Robinson, W.; Burgett, W.; Dombeck, T.; Gannon, J.; Kraushaar, P.; McInturff, A.; Savord, T.; Tool, G.

    1993-05-01

    The string test facility was constructed to provide a development test bed for the arc regions of the Superconducting Super Collider (SSC). Significant effort has been devoted to the development and testing of superconducting magnets, spools, and accelerator control systems required for the SSC. The string test facility provides the necessary environment required to evaluate the operational performance of these components as they are configured as an accelerator lens in the collider. This discussion will review the results of high current testing of the string conducted to evaluate magnet element uniformity and compatibility, the splice resistance used to connect the magnets, and system response to various quench conditions. Performance results of the spools, energy bypass systems, energy dump, and the power supply system are also discussed

  13. Devaney's chaos on uniform limit maps

    International Nuclear Information System (INIS)

    Yan Kesong; Zeng Fanping; Zhang Gengrong

    2011-01-01

    Highlights: → The transitivity may not been inherited even if the sequence functions mixing. → The sensitivity may not been inherited even if the iterates of sequence have some uniform convergence. → Some equivalence conditions for the transitivity and sensitivity for uniform limit function are given. → A non-transitive sequence may converge uniformly to a transitive map. - Abstract: Let (X, d) be a compact metric space and f n : X → X a sequence of continuous maps such that (f n ) converges uniformly to a map f. The purpose of this paper is to study the Devaney's chaos on the uniform limit f. On the one hand, we show that f is not necessarily transitive even if all f n mixing, and the sensitive dependence on initial conditions may not been inherited to f even if the iterates of the sequence have some uniform convergence, which correct two wrong claims in . On the other hand, we give some equivalence conditions for the uniform limit f to be transitive and to have sensitive dependence on initial conditions. Moreover, we present an example to show that a non-transitive sequence may converge uniformly to a transitive map.

  14. Design and performance of a 3.3-MeV linear induction accelerator (LIA)

    International Nuclear Information System (INIS)

    Cheng Nianan; Zhang Shouyun; Tao Zucong

    1992-01-01

    A 3.3-MeV linear induction accelerator (LIA) has been designed and constructed at the China Academy of Engineering Physics. The parameters of 3.4 MeV, 2 kA, 80 ns and 1 x 10 4 A/(rad.cm) 2 have been achieved. It has been used for SG-1 FEL experiments. The accelerator is mounted on a movable frame so that , after moving 3 m transversely, it can be assembled with more modules into a 10-MeV LIA. The authors summarize the physics and engineering aspects of the LIA facility and describe the measuring means of characters for the beam

  15. Framing of health information messages.

    Science.gov (United States)

    Akl, Elie A; Oxman, Andrew D; Herrin, Jeph; Vist, Gunn E; Terrenato, Irene; Sperati, Francesca; Costiniuk, Cecilia; Blank, Diana; Schünemann, Holger

    2011-12-07

    The same information about the evidence on health effects can be framed either in positive words or in negative words. Some research suggests that positive versus negative framing can lead to different decisions, a phenomenon described as the framing effect. Attribute framing is the positive versus negative description of a specific attribute of a single item or a state, for example, "the chance of survival with cancer is 2/3" versus "the chance of mortality with cancer is 1/3". Goal framing is the description of the consequences of performing or not performing an act as a gain versus a loss, for example, "if you undergo a screening test for cancer, your survival will be prolonged" versus "if you don't undergo screening test for cancer, your survival will be shortened". To evaluate the effects of attribute (positive versus negative) framing and of goal (gain versus loss) framing of the same health information, on understanding, perception of effectiveness, persuasiveness, and behavior of health professionals, policy makers, and consumers. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, issue 3 2007), MEDLINE (Ovid) (1966 to October 2007), EMBASE (Ovid) (1980 to October 2007), PsycINFO (Ovid) (1887 to October 2007). There were no language restrictions. We reviewed the reference lists of related systematic reviews, included studies and of excluded but closely related studies. We also contacted experts in the field. We included randomized controlled trials, quasi-randomised controlled trials, and cross-over studies with health professionals, policy makers, and consumers evaluating one of the two types of framing. Two review authors extracted data in duplicate and independently. We graded the quality of evidence for each outcome using the GRADE approach. We standardized the outcome effects using standardized mean difference (SMD). We stratified the analysis by the type of framing (attribute, goal) and conducted pre

  16. Pairs of dual periodic frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2012-01-01

    The time–frequency analysis of a signal is often performed via a series expansion arising from well-localized building blocks. Typically, the building blocks are based on frames having either Gabor or wavelet structure. In order to calculate the coefficients in the series expansion, a dual frame...... is needed. The purpose of the present paper is to provide constructions of dual pairs of frames in the setting of the Hilbert space of periodic functions L2(0,2π). The frames constructed are given explicitly as trigonometric polynomials, which allows for an efficient calculation of the coefficients...

  17. Highly accelerated acquisition and homogeneous image reconstruction with rotating RF coil array at 7T-A phantom based study.

    Science.gov (United States)

    Li, Mingyan; Zuo, Zhentao; Jin, Jin; Xue, Rong; Trakic, Adnan; Weber, Ewald; Liu, Feng; Crozier, Stuart

    2014-03-01

    Parallel imaging (PI) is widely used for imaging acceleration by means of coil spatial sensitivities associated with phased array coils (PACs). By employing a time-division multiplexing technique, a single-channel rotating radiofrequency coil (RRFC) provides an alternative method to reduce scan time. Strategically combining these two concepts could provide enhanced acceleration and efficiency. In this work, the imaging acceleration ability and homogeneous image reconstruction strategy of 4-element rotating radiofrequency coil array (RRFCA) was numerically investigated and experimental validated at 7T with a homogeneous phantom. Each coil of RRFCA was capable of acquiring a large number of sensitivity profiles, leading to a better acceleration performance illustrated by the improved geometry-maps that have lower maximum values and more uniform distributions compared to 4- and 8-element stationary arrays. A reconstruction algorithm, rotating SENSitivity Encoding (rotating SENSE), was proposed to provide image reconstruction. Additionally, by optimally choosing the angular sampling positions and transmit profiles under the rotating scheme, phantom images could be faithfully reconstructed. The results indicate that, the proposed technique is able to provide homogeneous reconstructions with overall higher and more uniform signal-to-noise ratio (SNR) distributions at high reduction factors. It is hoped that, by employing the high imaging acceleration and homogeneous imaging reconstruction ability of RRFCA, the proposed method will facilitate human imaging for ultra high field MRI. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Shake-table testing of a self-centering precast reinforced concrete frame with shear walls

    Science.gov (United States)

    Lu, Xilin; Yang, Boya; Zhao, Bin

    2018-04-01

    The seismic performance of a self-centering precast reinforced concrete (RC) frame with shear walls was investigated in this paper. The lateral force resistance was provided by self-centering precast RC shear walls (SPCW), which utilize a combination of unbonded prestressed post-tensioned (PT) tendons and mild steel reinforcing bars for flexural resistance across base joints. The structures concentrated deformations at the bottom joints and the unbonded PT tendons provided the self-centering restoring force. A 1/3-scale model of a five-story self-centering RC frame with shear walls was designed and tested on a shake-table under a series of bi-directional earthquake excitations with increasing intensity. The acceleration response, roof displacement, inter-story drifts, residual drifts, shear force ratios, hysteresis curves, and local behaviour of the test specimen were analysed and evaluated. The results demonstrated that seismic performance of the test specimen was satisfactory in the plane of the shear wall; however, the structure sustained inter-story drift levels up to 2.45%. Negligible residual drifts were recorded after all applied earthquake excitations. Based on the shake-table test results, it is feasible to apply and popularize a self-centering precast RC frame with shear walls as a structural system in seismic regions.

  19. A Hardware Accelerator for Fault Simulation Utilizing a Reconfigurable Array Architecture

    Directory of Open Access Journals (Sweden)

    Sungho Kang

    1996-01-01

    Full Text Available In order to reduce cost and to achieve high speed a new hardware accelerator for fault simulation has been designed. The architecture of the new accelerator is based on a reconfigurabl mesh type processing element (PE array. Circuit elements at the same topological level are simulated concurrently, as in a pipelined process. A new parallel simulation algorithm expands all of the gates to two input gates in order to limit the number of faults to two at each gate, so that the faults can be distributed uniformly throughout the PE array. The PE array reconfiguration operation provides a simulation speed advantage by maximizing the use of each PE cell.

  20. Frame-less image-guided intracranial and extracranial radiosurgery using the Cyberknife robotic system

    International Nuclear Information System (INIS)

    Gibbs, I.C.

    2006-01-01

    The Cyberknife TM is an image-guided robotic radiosurgery system. The image guidance system includes a kilo-voltage X-ray imaging source and amorphous silica detectors. The radiation delivery device is a mobile X-band linear accelerator mounted onto a robotic arm. Through a highly complex interplay between the image guidance system, an automated couch, and the high-speed linear accelerator, near real-time tracking of the target is achieved. The Cyberknife TM gained Federal Drug Administration clearance in the United States in 2001 for treatment of tumors 'anywhere in the body where radiation treatment is indicated'. Because the Cyberknife TM system does not rely on rigid fixation of a stereotactic frame, tumors outside of the intracranial compartment, even those tumors that move with respiration can be treated with a similar degree of ease as intracranial targets. A description of the Cyberknife TM technology and a review of some of the current intracranial and extracranial applications are detailed herein. (author)

  1. Role of accelerator-driven systems in waste incineration scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Salvatores, M.; Slessarev, I.; Tchistiakov, A. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Direction des Reacteurs Nucleaires; Spiro, M.; Terrien, Y.; Mouney, H.; Vergnes, J.

    1997-12-31

    At CEA accelerator-driven systems (ADS) are studied in the frame of the R and D required to answer the request of a law voted in 1991 by the French Parliament, `to search for solutions allowing to partition and transmute long lived radioactive wastes, in order to reduce their volume and toxicity`. These systems (called `INCAs`) are still at a conceptual level. However, the role of ADS has been clarified as a first step, and this will be the subject of the present paper. (author)

  2. Characteristics of Philips SL-20 linear accelerator used for stereotactic radiosurgery/radiotherapy

    International Nuclear Information System (INIS)

    D'Souza, Harold; Ganesh, T.; Joshi, R.C.; Julka, P.K.; Rath, G.K.; Chander, Subhash; Pant, G.S.

    2002-01-01

    Commissioning of a stereotactic radiosurgery/stereotactic radiotherapy (SRS/SRT) facility on a modified linear accelerator requires validation of mechanical parameters and establishment of parameters, such as tissue maximum ratio (TMR), relative output factors (OF), and off axis ratios (OAR). The mechanical and beam characteristics of Philips SL-20 linear accelerator modified for SRS/SRT were evaluated and presented. The SRS/SRT procedure carried on Philips SL-20 linear accelerator with Brown-Robert-Wells (BRW) and relocatable Gill-Thomas-Cosman (GTC) head frames along with the Radionics planning system was evaluated. The tertiary collimator consists of the actual treatment cones and their sizes vary from 12.5 mm to 40 mm diameter. The alignment of the auxillary collimator axis with mechanical axes and stability of the isocenter of Philips SL-20 machine was evaluated using Iso-Align device and mechanical isocenter standard (MIS). All the mechanical errors of the linear accelerator were within 1 mm, except the stability of the isocenter while rotating the couch. Alignment of auxiliary collimator axis with the central axis, gantry and couch axes were achieved. The TMR, OF and OAR for 6 MV x-rays from Philips SL-20 linear accelerator for different cone sizes were deduced using a Multidata water phantom with 0.015 cc ion chamber. The difference between 50% width of profiles in two major axes (x and y) were within ± 0.4 mm. The cone dimensions were accurate up to 0.7 mm. The penumbra width for different cones varies from 3.1 mm to 3.5 mm. Dose linearity of the monitoring system was ≤ 1% above 5 MU. The mechanical and beam characteristics including dose linearity of the SL-20 machine are presented. The beam characteristics of this machine are comparable with the other modified linear accelerators for SRS/SRT. The shift of isocenter during rotation of couch can be nullified by fine adjusting laser target localizing frame to the laser position using micrometer screws

  3. Approximation of the inverse G-frame operator

    Indian Academy of Sciences (India)

    ... projection method for -frames which works for all conditional -Riesz frames. We also derive a method for approximation of the inverse -frame operator which is efficient for all -frames. We show how the inverse of -frame operator can be approximated as close as we like using finite-dimensional linear algebra.

  4. Acceleration of particles by black holes: Kinematic explanation

    International Nuclear Information System (INIS)

    Zaslavskii, O. B.

    2011-01-01

    A new simple and general explanation of the effect of acceleration of particles by black holes to infinite energies in the center of mass frame is suggested. It is based on kinematics of particles moving near the horizon. This effect arises when particles of two kinds collide near the horizon. For massive particles, the first kind represents a particle with the generic energy and angular momentum (I call them ''usual''). Near the horizon, such a particle has a velocity almost equal to that of light in the frame that corotates with a black hole (the frame is static if a black hole is static). The second kind (called ''critical'') consists of particles with the velocity v< c near the horizon due to special relationship between the energy and angular momentum (or charge). As a result, the relative velocity approaches the speed of light c, and the Lorentz factor grows unbound. This explanation applies both to generic rotating black holes and charged ones (even for radial motion of particles). If one of the colliding particles is massless (photon), the critical particle is distinguished by the fact that its frequency is finite near the horizon. The existence (or absence) of the effect is determined depending on competition of two factors--gravitational blue shift for a photon propagating towards a black hole and the Doppler effect due to transformation from the locally nonrotating frame to a comoving one. Classification of all possible types of collisions is suggested depending on whether massive or massless particle is critical or usual.

  5. Adding muscle where you need it: non-uniform hypertrophy patterns in elite sprinters.

    Science.gov (United States)

    Handsfield, G G; Knaus, K R; Fiorentino, N M; Meyer, C H; Hart, J M; Blemker, S S

    2017-10-01

    Sprint runners achieve much higher gait velocities and accelerations than average humans, due in part to large forces generated by their lower limb muscles. Various factors have been explored in the past to understand sprint biomechanics, but the distribution of muscle volumes in the lower limb has not been investigated in elite sprinters. In this study, we used non-Cartesian MRI to determine muscle sizes in vivo in a group of 15 NCAA Division I sprinters. Normalizing muscle sizes by body size, we compared sprinter muscles to non-sprinter muscles, calculated Z-scores to determine non-uniformly large muscles in sprinters, assessed bilateral symmetry, and assessed gender differences in sprinters' muscles. While limb musculature per height-mass was 22% greater in sprinters than in non-sprinters, individual muscles were not all uniformly larger. Hip- and knee-crossing muscles were significantly larger among sprinters (mean difference: 30%, range: 19-54%) but only one ankle-crossing muscle was significantly larger (tibialis posterior, 28%). Population-wide asymmetry was not significant in the sprint population but individual muscle asymmetries exceeded 15%. Gender differences in normalized muscle sizes were not significant. The results of this study suggest that non-uniform hypertrophy patterns, particularly large hip and knee flexors and extensors, are advantageous for fast sprinting. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. The Los Alamos accelerator driven transmutation of nuclear waste (ATW) concept development of the ATW target/blanket system

    International Nuclear Information System (INIS)

    Venneri, F.; Williamson, M.A.; Ning, L.

    1997-01-01

    The studies carried out in the frame of the Accelerator Driven Transmutation Technology (ADTT) program developed at Los Alamos in order to solve the nuclear waste problem and to build a new generation of safer and non-proliferant nuclear power plants, are presented

  7. Technological Frame Incongruence, Diffusion, and Noncompliance

    Science.gov (United States)

    Sobreperez, Polly

    The technological frames of reference strand of social shaping of technology theory is used to overlay the issues arising from a case study looking at noncompliance with information systems. A recent review of the theory suggests that although frame content is often addressed, frame structure, the process of framing, and the characteristics and outcomes of frames are largely overlooked. This paper attempts to address this shortfall by applying the indicators identified by case study research to the frames of different groups and using them to highlight differing perceptions and attitudes. In this way, the author suggests that issues surrounding noncompliance should not be dismissed as resistance but instead should be further studied by managers and developers, leading to accommodation of differing views. Further examination of frame incongruence reveals dependence on inefficient or ineffective organizational situations and thus these indicators can be useful in future studies to identify and address procedural, acceptance and cultural issues leading to acts of noncompliance.

  8. Field-reversed bubble in deep plasma channels for high quality electron acceleration

    CERN Document Server

    Pukhov, A; Tueckmantel, T; Thomas, J; Yu, I; Kostyukov, Yu

    2014-01-01

    We study hollow plasma channels with smooth boundaries for laser-driven electron acceleration in the bubble regime. Contrary to the uniform plasma case, the laser forms no optical shock and no etching at the front. This increases the effective bubble phase velocity and energy gain. The longitudinal field has a plateau that allows for mono-energetic acceleration. We observe as low as 10−3 r.m.s. relative witness beam energy uncertainty in each cross-section and 0.3% total energy spread. By varying plasma density profile inside a deep channel, the bubble fields can be adjusted to balance the laser depletion and dephasing lengths. Bubble scaling laws for the deep channel are derived. Ultra-short pancake-like laser pulses lead to the highest energies of accelerated electrons per Joule of laser pulse energy.

  9. Beam stability of cyclotron accelerator for therapy at National Cancer Center Hospital East

    International Nuclear Information System (INIS)

    Nishio, T.; Ogino, T.; Shinbo, M.; Ikeda, H.; Tachikawa, T.; Kumata, Y.

    2000-01-01

    In 1997, the proton-treatment facility that has the therapeutic AVF cyclotron accelerator (C235), is constructed at National Cancer Center Hospital East. The facility has 3-irradiation ports (rooms) that are 2-rotationg gantry ports and 1-horizontal fixed port. The C235 can accelerate proton to 235 MeV with the beam intensity of 300 nA. The external diameter is a very compact with about 4 m. The radio frequency is 106 MHz, the accelerating voltage is about 60 kV, and the harmonic number is 4. A beam stability of the C235 has an important relation with the uniformity of an irradiation field and is a very difficulty. The measured result indicated that the incident beam position must be into the 0.5-mmφ circle. (author)

  10. Multimodal news framing effects

    NARCIS (Netherlands)

    Powell, T.E.

    2017-01-01

    Visuals in news media play a vital role in framing citizens’ political preferences. Yet, compared to the written word, visual images are undervalued in political communication research. Using framing theory, this thesis redresses the balance by studying the combined, or multimodal, effects of visual

  11. Framing in criminal investigation

    Science.gov (United States)

    2016-01-01

    Failures in criminal investigation may lead to wrongful convictions. Insight in the criminal investigation process is needed to understand how these investigative failures may rise and how measures can contribute to the prevention of this kind of failures. Some of the main findings of an empirical study of the criminal investigation process in four cases of major investigations are presented here. This criminal investigation process is analyzed as a process of framing, using Goffman's framing (Goffman, 1975) and interaction theories (Goffman, 1990). It shows that in addition to framing, other substantive and social factors affect the criminal investigation. PMID:29046594

  12. Pole inflation in Jordan frame supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Saikawa, Ken' ichi [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yamaguchi, Masahide [Tokyo Institute of Technology, Ookayama (Japan). Dept. of Physics; Yamashita, Yasuho [Kyoto Univ. (Japan). Yukawa Inst. for Theoretical Physics; Yoshida, Daisuke [Montreal Univ., QC (Canada). Dept. of Physics

    2017-09-15

    We investigate inflation models in Jordan frame supergravity, in which an inflaton non-minimally couples to the scalar curvature. By imposing the condition that an inflaton would have the canonical kinetic term in the Jordan frame, we construct inflation models with asymptotically flat potential through pole inflation technique and discuss their relation to the models based on Einstein frame supergravity. We also show that the model proposed by Ferrara et al. has special position and the relation between the Kaehler potential and the frame function is uniquely determined by requiring that scalars take the canonical kinetic terms in the Jordan frame and that a frame function consists only of a holomorphic term (and its anti-holomorphic counterpart) for symmetry breaking terms. Our case corresponds to relaxing the latter condition.

  13. Pole inflation in Jordan frame supergravity

    International Nuclear Information System (INIS)

    Saikawa, Ken'ichi; Yamaguchi, Masahide; Yamashita, Yasuho; Yoshida, Daisuke

    2017-09-01

    We investigate inflation models in Jordan frame supergravity, in which an inflaton non-minimally couples to the scalar curvature. By imposing the condition that an inflaton would have the canonical kinetic term in the Jordan frame, we construct inflation models with asymptotically flat potential through pole inflation technique and discuss their relation to the models based on Einstein frame supergravity. We also show that the model proposed by Ferrara et al. has special position and the relation between the Kaehler potential and the frame function is uniquely determined by requiring that scalars take the canonical kinetic terms in the Jordan frame and that a frame function consists only of a holomorphic term (and its anti-holomorphic counterpart) for symmetry breaking terms. Our case corresponds to relaxing the latter condition.

  14. An algorithm for online optimization of accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaobiao [SLAC National Accelerator Lab., Menlo Park, CA (United States); Corbett, Jeff [SLAC National Accelerator Lab., Menlo Park, CA (United States); Safranek, James [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wu, Juhao [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2013-10-01

    We developed a general algorithm for online optimization of accelerator performance, i.e., online tuning, using the performance measure as the objective function. This method, named robust conjugate direction search (RCDS), combines the conjugate direction set approach of Powell's method with a robust line optimizer which considers the random noise in bracketing the minimum and uses parabolic fit of data points that uniformly sample the bracketed zone. Moreover, it is much more robust against noise than traditional algorithms and is therefore suitable for online application. Simulation and experimental studies have been carried out to demonstrate the strength of the new algorithm.

  15. Experimental study on the CHF in uniformly and non-uniformly heated vertical annuli

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Se Young; Moon, Sang Ki; Chung, Heung June; Park, Jong Kuk; Kim, Bok Deuk; Youn, Young Jung; Chung, Moon Ki

    2001-09-01

    Up to now, KAERI has performed critical heat flux experiments in water under zero-flow and low-flow conditions using a RCS CHF loop facility with uniformly and non-uniformly heated vertical annulus. Since the existing CHF experiments were mainly performed under low-pressure conditions, we performed the CHF experiment to investigate the pressure effect on the CHF under zero-flow and low-flow conditions for a wide range of system pressures. Also, two vertical annuli with the same geometry have been used to investigate the axial heat flux distributions on the CHF. This report summarizes the experimental results and provides the CHF data that can be used for the development for CHF correlation and a thermal hydraulic analysis code. The CHF data have been collected for system pressures ranging from 0.57 to 15.15 MPa, mass flux 0 and from 200 to 650 kg/m2s, inlet subcooling from 75 to 360 kJ/kg and exit quality from 0.07 to 0.57. At low-flow conditions, the total number of data are 242 and 290 with uniformly heated- and non-uniformly heated test sections, respectively. 41 and 94 CHF data are generated with uniformly heated- and non-uniformly heated test sections, respectively, in zero-flow CHF experiments that are performed by blocking test section bottoms. The CHF experiment result shows that the effects of system pressure, mass flux and inlet subcooling are consistent with conventional understandings and similar to those for round tubes. The behavior of the CHF is relatively complex at low pressures. Also, the effects of axial heat flux profile are large at low-pressure conditions.

  16. Experimental study on the CHF in uniformly and non-uniformly heated vertical annuli

    International Nuclear Information System (INIS)

    Chun, Se Young; Moon, Sang Ki; Chung, Heung June; Park, Jong Kuk; Kim, Bok Deuk; Youn, Young Jung; Chung, Moon Ki

    2001-09-01

    Up to now, KAERI has performed critical heat flux experiments in water under zero-flow and low-flow conditions using a RCS CHF loop facility with uniformly and non-uniformly heated vertical annulus. Since the existing CHF experiments were mainly performed under low-pressure conditions, we performed the CHF experiment to investigate the pressure effect on the CHF under zero-flow and low-flow conditions for a wide range of system pressures. Also, two vertical annuli with the same geometry have been used to investigate the axial heat flux distributions on the CHF. This report summarizes the experimental results and provides the CHF data that can be used for the development for CHF correlation and a thermal hydraulic analysis code. The CHF data have been collected for system pressures ranging from 0.57 to 15.15 MPa, mass flux 0 and from 200 to 650 kg/m2s, inlet subcooling from 75 to 360 kJ/kg and exit quality from 0.07 to 0.57. At low-flow conditions, the total number of data are 242 and 290 with uniformly heated- and non-uniformly heated test sections, respectively. 41 and 94 CHF data are generated with uniformly heated- and non-uniformly heated test sections, respectively, in zero-flow CHF experiments that are performed by blocking test section bottoms. The CHF experiment result shows that the effects of system pressure, mass flux and inlet subcooling are consistent with conventional understandings and similar to those for round tubes. The behavior of the CHF is relatively complex at low pressures. Also, the effects of axial heat flux profile are large at low-pressure conditions

  17. Development and application of high-precision laser welding technology for manufacturing Ti alloy frames of glasses

    International Nuclear Information System (INIS)

    Kim, S. S.; Yang, M. S.; Kim, W. K.; Lee, D. Y.; Kim, J. M.; Leem, B. C.; Shin, J. S.; Lee, D. H.

    1999-12-01

    The research and development efforts of the high precision laser welding technology for manufacturing titanium alloy frames of glasses. For this purpose, laser welding device with the high beam quality is designed and fabricated, which consists of a optical fiber transmission part, a welding monitoring part and a welding controller. The welding nozzle and holding fixtures for manufacturing titanium and shape memory alloy frames of glasses. Titanium and shape memory alloy frames of glasses to be developed were experimentally manufactured by utilizing the laser welding using the optical fiber of GI 400 μm. As a result, the seam welding with the bead width of 0.3 mm or less and the weld penetration of 0.3-0.4mm could be accomplished. The fundamental technology was established through design of welding jigs with a variety of configurations and adequate welding conditions. Also, for the purpose to enable the companies participating in this project to commercialize the developed technology acceleratedly, a training program for the engineers belonging to such companies was conducted along with the technology transfer through joint experiments with the engineers. (author)

  18. 6 MV Folded Tandem Ion Accelerator facility at BARC

    International Nuclear Information System (INIS)

    Gupta, S.K.

    2010-01-01

    The 6 MV Folded Tandem Ion Accelerator (FOTIA) facility is operational round the clock and accelerated beams of both light and heavy ions are being used extensively by various divisions of BARC, Universities, lIT Bombay and other R and D labs across the country. The FOTIA is an upgraded version of the old 5.5 MV single stage Van-de-Graaff accelerator (1962-1992). Since its commissioning in the year 2000, the poor beam transmission through the 180 deg folding magnet was a matter of concern. A systematic study for beam transmission through the accelerator was carried out and progressive modifications in folding magnet chamber, foil stripper holder and improvement in average vacuum level through the accelerator have resulted in large improvement of beam transmission leading to up to 2.0 micro-amp analyzed proton beams on target. Now the utilization of the beams from the accelerator has increased many folds for basic and applied research in the fields of atomic and nuclear physics, material science and radiation biology etc. Few new beam lines after the indigenously developed 5-port switching magnet are added and the experimental setup for PIXE, PIGE, External PIXE, 4 neutron detector, Proton Induced Positron Annihilation Spectroscopy (PIPAS) setup and the general purpose scattering chamber etc have been commissioned in the beam hall. The same team has developed a Low Energy Accelerator Facility (LEAF) which delivers negative ions of light and heavy ions for application in implantation, irradiation damage studies in semiconductor devices and testing of new beam line components being developed for Low Energy High Intensity Proton Accelerator (LEHIPA) programme at BARC. The LEAF has been developed as stand alone facility and can deliver beam quickly with minimum intervention of the operator. Few more features are being planned to deliver uniform scanned beams on large targets. (author)

  19. School Uniforms. Research Brief

    Science.gov (United States)

    Walker, Karen

    2007-01-01

    Does clothing make the person or does the person make the clothing? How does what attire a student wears to school affect their academic achievement? In 1996, President Clinton cited examples of school violence and discipline issues that might have been avoided had the students been wearing uniforms ("School uniforms: Prevention or suppression?").…

  20. Accelerator breeder: a viable option for the production of nuclear fuels

    International Nuclear Information System (INIS)

    Grand, P.

    1983-01-01

    Despite the growing pains of the US nuclear power industry, our dependence on nuclear energy for the production of electricity and possibly process heat is likely to increase dramatically over the next few deacades. This statement dismisses fusion as being entirely too speculative to be practical within that time frame. Sometime, between the years 2000 and 2050, fissile material will be in short supply whether it is to fuel existing LWR's or to provide initial fuel inventory for FBR's. The accelerator breeder could produce the fuel shortfall predicted to occur during the first half of the 21st century. The accelerator breeder offers the only practical means today of producing, or breeding, large quantities of fissile fuel from fertile materials, albeit at high cost. Studies performed over the last few years at Chalk River Laboratory and at Brookhaven National Laboratory have demonstrated that the accelerator breeder is practical, technically feasible with state-of-the-art technology, and is economically competitive with any other proposed synthetic means of fissile fuel production. This paper gives the parameters of a nearly optimized accelerator-breeder system, then discusses the development needs, and the economics and institutional problems that this breeding concept faces

  1. On the Seismic Response of Protected and Unprotected Middle-Rise Steel Frames in Far-Field and Near-Field Areas

    Directory of Open Access Journals (Sweden)

    Dora Foti

    2014-01-01

    Full Text Available Several steel moment-resisting framed buildings were seriously damaged during Northridge (1994; Kobe (1995; Kocaeli, Turkey (1999, earthquakes. Indeed, for all these cases, the earthquake source was located under the urban area and most victims were in near-field areas. In fact near-field ground motions show velocity and displacement peaks higher than far-field ones. Therefore, the importance of considering near-field ground motion effects in the seismic design of structures is clear. This study analyzes the seismic response of five-story steel moment-resisting frames subjected to Loma Prieta (1989 earthquake—Gilroy (far-field register and Santa Cruz (near-field register. The design of the frames verifies all the resistance and stability Eurocodes’ requirements and the first mode has been determined from previous shaking-table tests. In the frames two diagonal braces are installed in different positions. Therefore, ten cases with different periods are considered. Also, friction dampers are installed in substitution of the braces. The behaviour of the braced models under the far-field and the near-field records is analysed. The responses of the aforementioned frames equipped with friction dampers and subjected to the same ground motions are discussed. The maximum response of the examined model structures with and without passive dampers is analysed in terms of damage indices, acceleration amplification, base shear, and interstory drifts.

  2. Quantum metrology of phase for accelerated two-level atom coupled with electromagnetic field with and without boundary

    Science.gov (United States)

    Yang, Ying; Liu, Xiaobao; Wang, Jieci; Jing, Jiliang

    2018-03-01

    We study how to improve the precision of the quantum estimation of phase for an uniformly accelerated atom in fluctuating electromagnetic field by reflecting boundaries. We find that the precision decreases with increases of the acceleration without the boundary. With the presence of a reflecting boundary, the precision depends on the atomic polarization, position and acceleration, which can be effectively enhanced compared to the case without boundary if we choose the appropriate conditions. In particular, with the presence of two parallel reflecting boundaries, we obtain the optimal precision for atomic parallel polarization and the special distance between two boundaries, as if the atom were shielded from the fluctuation.

  3. Framing effects: The impact of framing on copresence in virtual theatre

    OpenAIRE

    Unterman, Benjamin Asher

    2017-01-01

    Virtual theatre (enacted dramatic narrative performed live online) is an emerging form of theatrical mediation. One of the biggest challenges faced by this growing media practice is the management of audience experience. This thesis attempts to address the uncertainty around virtual theatre audiences by focusing on the framing of performances that take place in virtual worlds. Strategic approaches to framing and audience preparation are suggested based on literature-based research, case studi...

  4. Orthogonal Multiwavelet Frames in L2Rd

    Directory of Open Access Journals (Sweden)

    Liu Zhanwei

    2012-01-01

    Full Text Available We characterize the orthogonal frames and orthogonal multiwavelet frames in L2Rd with matrix dilations of the form (Df(x=detAf(Ax, where A is an arbitrary expanding d×d matrix with integer coefficients. Firstly, through two arbitrarily multiwavelet frames, we give a simple construction of a pair of orthogonal multiwavelet frames. Then, by using the unitary extension principle, we present an algorithm for the construction of arbitrarily many orthogonal multiwavelet tight frames. Finally, we give a general construction algorithm for orthogonal multiwavelet tight frames from a scaling function.

  5. Department of Accelerator Physics and Technology: Overview

    International Nuclear Information System (INIS)

    Pachan, M.

    2001-01-01

    version of pre bunchers and bunching structure for injector linac in Trieste synchrotron. It is also worthwhile to notice the important proposal for research and construction works on a new electron accelerator with high beam power dedicated to radiation technology. The offer for this project was presented in the frame of Multiyear Programme ''ISOTOPES AND ACCELERATORS''. Most interesting results of recent works, were presented at the 7th European Particle Accelerator Conference EPAC 2000 - Vienna. (author)

  6. Impact of compressibility and a guide field on Fermi acceleration during magnetic island coalescence

    Science.gov (United States)

    Montag, Peter; Egedal, Jan; Lichko, Emily; Wetherton, Blake

    2017-10-01

    Previous work has shown that Fermi acceleration can be an effective heating mechanism during magnetic island coalescence, where electrons may undergo repeated reflections as the magnetic field lines contract. This energization has the potential to account for the power-law distributions of particle energy inferred from observations of solar flares. Here, we develop a generalized framework for the analysis of Fermi acceleration that can incorporate the effects of compressibility and non-uniformity along field lines, which have commonly been neglected in previous treatments of the problem. Applying this framework to the simplified case of the uniform flux tube allows us to find both the power-law scaling of the distribution function and the rate at which the power-law behavior develops. We find that a guide magnetic field of order unity effectively suppresses the development of power-law distributions. The work was supported by NASA Grant No. NNX14AC68G, NSF GEM Grant No. 1405166, NSF Award 1404166, and NASA Award NNX15AJ73G.

  7. Framing, intentions, and trust-choice incompatibility

    NARCIS (Netherlands)

    Keren, G.B.

    2007-01-01

    The present paper examines how framing of messages and the intentions inferred from different—positive vs. negative—framings, interact with the development of trust. Empirical evidence is presented showing that different, logically equivalent, frames are supposedly interpreted as implying different

  8. New control architecture for the SPS accelerator at CERN

    International Nuclear Information System (INIS)

    Kissler, K.H.; Rausch, R.

    1992-01-01

    The Control System for the 450 Gev proton accelerator SPS at CERN was conceived and implemented some 18 years ago. The 16 Bit minicomputers with their proprietary operating system and interconnection with a dedicated network do not permit the use of modern workstations, international communication standards and industrial software packages. The upgrading of the system has therefore become necessary. After a short review of the history and the current state of the SPS control system, the paper describes how CERN's new control architecture, which will be common to all accelerators, will be realized at the SPS. The migration path ensuring a smooth transition to the final system is outlined. Once the SPS upgrade is complete and following some enhancements to the LEP control system, the operator in the SPS/LEP control center will be working in a single uniform control environment. (author)

  9. High Performance Commercial Fenestration Framing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mike Manteghi; Sneh Kumar; Joshua Early; Bhaskar Adusumalli

    2010-01-31

    A major objective of the U.S. Department of Energy is to have a zero energy commercial building by the year 2025. Windows have a major influence on the energy performance of the building envelope as they control over 55% of building energy load, and represent one important area where technologies can be developed to save energy. Aluminum framing systems are used in over 80% of commercial fenestration products (i.e. windows, curtain walls, store fronts, etc.). Aluminum framing systems are often required in commercial buildings because of their inherent good structural properties and long service life, which is required from commercial and architectural frames. At the same time, they are lightweight and durable, requiring very little maintenance, and offer design flexibility. An additional benefit of aluminum framing systems is their relatively low cost and easy manufacturability. Aluminum, being an easily recyclable material, also offers sustainable features. However, from energy efficiency point of view, aluminum frames have lower thermal performance due to the very high thermal conductivity of aluminum. Fenestration systems constructed of aluminum alloys therefore have lower performance in terms of being effective barrier to energy transfer (heat loss or gain). Despite the lower energy performance, aluminum is the choice material for commercial framing systems and dominates the commercial/architectural fenestration market because of the reasons mentioned above. In addition, there is no other cost effective and energy efficient replacement material available to take place of aluminum in the commercial/architectural market. Hence it is imperative to improve the performance of aluminum framing system to improve the energy performance of commercial fenestration system and in turn reduce the energy consumption of commercial building and achieve zero energy building by 2025. The objective of this project was to develop high performance, energy efficient commercial

  10. Strategic framing in the BP crisis: A semantic network analysis of associative frames

    NARCIS (Netherlands)

    Schultz, F.; Kleinnijenhuis, J.; Oegema, D.; Utz, S.; van Atteveldt, W.H.

    2012-01-01

    This paper contributes to the analysis of the interplay of public relations and news in crisis situations, and the conceptualization of strategic framing by introducing the idea of associative frames and the method of semantic network analysis to the PR research field. By building on a more advanced

  11. Postural adaptation of the spatial reference frames to microgravity: back to the egocentric reference frame.

    Directory of Open Access Journals (Sweden)

    Sébastien Viel

    Full Text Available BACKGROUND: In order to test how gravitational information would affect the choice of stable reference frame used to control posture and voluntary movement, we have analysed the forearm stabilisation during sit to stand movement under microgravity condition obtained during parabolic flights. In this study, we hypothesised that in response to the transient loss of graviceptive information, the postural adaptation might involve the use of several strategies of segmental stabilisation, depending on the subject's perceptual typology (dependence--independence with respect to the visual field. More precisely, we expected a continuum of postural strategies across subjects with 1 at one extreme the maintaining of an egocentric reference frame and 2 at the other the re-activation of childhood strategies consisting in adopting an egocentric reference frame. METHODOLOGY/PRINCIPAL FINDINGS: To check this point, a forearm stabilisation task combined with a sit to stand movement was performed with eyes closed by 11 subjects during parabolic flight campaigns. Kinematic data were collected during 1-g and 0-g periods. The postural adaptation to microgravity's constraint may be described as a continuum of strategies ranging from the use of an exo- to an egocentric reference frame for segmental stabilisation. At one extremity, the subjects used systematically an exocentric frame to control each of their body segments independently, as under normogravity conditions. At the other, the segmental stabilisation strategies consist in systematically adopting an egocentric reference frame to control their forearm's stabilisation. A strong correlation between the mode of segmental stabilisation used and the perceptual typology (dependence--independence with respect to the visual field of the subjects was reported. CONCLUSION: The results of this study show different subjects' typologies from those that use the forearm orientation in a mainly exocentric reference frame to

  12. Material studies in the frame of CLIC Accelerating structures production conducted within the Mechanics program together with Metso Oy

    CERN Document Server

    Nurminen, Janne

    2012-01-01

    MeChanICs (Marie Curie Linking Industry to CERN) is an Industry to Academia Partnership and Pathways (IAPP) platform for precision manufacturing knowledge exchange bringing together five Finnish manufacturing companies with Helsinki Insitute of Physics (HIP) and CERN. The scientific objective of MeChanICs project is to contribute to the manufacturing RTD of CLIC enabling technologies. The focus is on the design, materials, machining, brazing and assembly of A CLIC accelerating structure. This study deals with the materials work package of the program and wants to explore the following items: 1) producing copper accelerating structures for CLIC from raw copper powder by near net shape hot isostatic pressing (HIP). 2) The feasibility to use HIP diffusion bonding of the accelerator structures as a function of surface quality and applied temperature and pressure. 3) Brazing for CLIC AS auxiliary systems, like water cooling or damping manifolds, to the disc stack by coating one of the brazing partners with an enab...

  13. Does perceived risk influence the effects of message framing? Revisiting the link between prospect theory and message framing.

    Science.gov (United States)

    Van 't Riet, Jonathan; Cox, Anthony D; Cox, Dena; Zimet, Gregory D; De Bruijn, Gert-Jan; Van den Putte, Bas; De Vries, Hein; Werrij, Marieke Q; Ruiter, Robert A C

    2016-12-01

    Health-promoting messages can be framed in terms of the beneficial consequences of healthy behaviour (gain-framed messages) or the detrimental consequences of unhealthy behaviour (loss-framed messages). An influential notion holds that the perceived risk associated with the recommended behaviour determines the relative persuasiveness of gain- and loss-framed messages. This 'risk-framing hypothesis', which was derived from prospect theory, has been central to health message-framing research for the better part of two decades and has enduring appeal to researchers and practitioners. It has found its way into several health communication handbooks and is communicated to the general public. The present article examines the validity of the risk-framing hypothesis anew by providing a review of the health message-framing literature. In spite of its ongoing appeal, we conclude that the hypothesis has severe theoretical flaws. In addition, we find that the empirical evidence in favour of the hypothesis is weak and inconsistent. It seems that, in applying prospect theory's tenets to a health-promotion context, some of the theory's key aspects have been lost in translation. At the close of the article, we offer a research agenda for the future, arguing that, above all, new methodology is needed to bring the message-framing literature further.

  14. The mathematical description of uniformity and related theorems

    International Nuclear Information System (INIS)

    Luo Chuanwen; Yi Chundi; Wang Gang; Li Longsuo; Wang Chuncheng

    2009-01-01

    Uniform index is a conception that can describe the uniformity of a finite point set in a polyhedron, and is closely related to chaos. In order to study uniform index, the concept of contained uniform index is defined, which is similar to uniform index and has good mathematical properties. In this paper, we prove the convergence of the contained uniform index, and develop the base of proving the convergence of uniform index.

  15. High-speed spectral domain optical coherence tomography using non-uniform fast Fourier transform

    Science.gov (United States)

    Chan, Kenny K. H.; Tang, Shuo

    2010-01-01

    The useful imaging range in spectral domain optical coherence tomography (SD-OCT) is often limited by the depth dependent sensitivity fall-off. Processing SD-OCT data with the non-uniform fast Fourier transform (NFFT) can improve the sensitivity fall-off at maximum depth by greater than 5dB concurrently with a 30 fold decrease in processing time compared to the fast Fourier transform with cubic spline interpolation method. NFFT can also improve local signal to noise ratio (SNR) and reduce image artifacts introduced in post-processing. Combined with parallel processing, NFFT is shown to have the ability to process up to 90k A-lines per second. High-speed SD-OCT imaging is demonstrated at camera-limited 100 frames per second on an ex-vivo squid eye. PMID:21258551

  16. The role of magnetic loops in particle acceleration at nearly perpendicular shocks

    Science.gov (United States)

    Decker, R. B.

    1993-01-01

    The acceleration of superthermal ions is investigated when a planar shock that is on average nearly perpendicular propagates through a plasma in which the magnetic field is the superposition of a constant uniform component plus a random field of transverse hydromagnetic fluctuations. The importance of the broadband nature of the transverse magnetic fluctuations in mediating ion acceleration at nearly perpendicular shocks is pointed out. Specifically, the fluctuations are composed of short-wavelength components which scatter ions in pitch angle and long-wavelength components which are responsible for a spatial meandering of field lines about the mean field. At nearly perpendicular shocks the field line meandering produces a distribution of transient loops along the shock. As an application of this model, the acceleration of a superthermal monoenergetic population of seed protons at a perpendicular shock is investigated by integrating along the exact phase-space orbits.

  17. Pseudo-set framing.

    Science.gov (United States)

    Barasz, Kate; John, Leslie K; Keenan, Elizabeth A; Norton, Michael I

    2017-10-01

    Pseudo-set framing-arbitrarily grouping items or tasks together as part of an apparent "set"-motivates people to reach perceived completion points. Pseudo-set framing changes gambling choices (Study 1), effort (Studies 2 and 3), giving behavior (Field Data and Study 4), and purchase decisions (Study 5). These effects persist in the absence of any reward, when a cost must be incurred, and after participants are explicitly informed of the arbitrariness of the set. Drawing on Gestalt psychology, we develop a conceptual account that predicts what will-and will not-act as a pseudo-set, and defines the psychological process through which these pseudo-sets affect behavior: over and above typical reference points, pseudo-set framing alters perceptions of (in)completeness, making intermediate progress seem less complete. In turn, these feelings of incompleteness motivate people to persist until the pseudo-set has been fulfilled. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Information Leakage from Logically Equivalent Frames

    Science.gov (United States)

    Sher, Shlomi; McKenzie, Craig R. M.

    2006-01-01

    Framing effects are said to occur when equivalent frames lead to different choices. However, the equivalence in question has been incompletely conceptualized. In a new normative analysis of framing effects, we complete the conceptualization by introducing the notion of information equivalence. Information equivalence obtains when no…

  19. Department of Accelerator Physics and Technology: Overview

    International Nuclear Information System (INIS)

    Pachan, M.

    2000-01-01

    selection of solution for accelerating structure operating in broad energy range 6 to 15 MeV; - advance in technique and metrology of narrow photon beams for stereotactic radiosurgery. Collaboration with DESY was concentrated on problems in design and modelling of accelerating structure for TESLA collider. Successive series of numerical calculations was effectuated for evaluation of conditions for excitation and suppressing of higher order field modes. The complete copper model of ''superstructure'' section has been built and measured in Swierk and Hamburg. In effect of positive results, a first series of niobium resonators for superconducting structure is in preparation. In the frame of Italian-Polish collaboration a new proposal has been prepared for design and construction of a 10-12 MeV bunching section in the injector of Trieste electron synchrotron. (author)

  20. Design of high-speed data transmission system for Lanzhou heavy ion therapy accelerator

    International Nuclear Information System (INIS)

    Mao Wenyu; Qiao Weimin; Jing Lan; Li Guihua

    2012-01-01

    In order to satisfy the transmission requirements of partial synchronization data and process data for the heavy ion therapy accelerator, a high-speed, error-correction, long-distance, and real-time data transmission system was proposed and achieved. It can improve the efficiency and reliability of the accelerator control and synchronization. The system optimizes the hardware configuration and layout of the traditional system. FPGA, gigabit fiber module, PXI and SDRAM are the main parts of the system. It replaces the low-speed, short-distance, and poor anti-interference of the traditional data path and the data processing chips. Through the programming in the two FPGA chips, the PXI and DMA transmission mode was used to exchange data with the server of the accelerator. The front-end of the system achieves a real-time, long-distance, and high-speed serial frame transmission with 800 MHz carrier and 100 MHz base band signal. The real-time -data like synchronous event signal, power waveform data of the heavy ion therapy accelerator can be transmitted efficiently between the server and the remote controller through the system. (authors)

  1. 49 CFR 230.106 - Steam locomotive frame.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive frame. 230.106 Section 230.106... Tenders Trucks, Frames and Equalizing System § 230.106 Steam locomotive frame. (a) Maintenance and inspection. Frames, decks, plates, tailpieces, pedestals, and braces shall be maintained in a safe and...

  2. ``Frames of Reference'' revisited

    Science.gov (United States)

    Steyn-Ross, Alistair; Ivey, Donald G.

    1992-12-01

    The PSSC teaching film, ``Frames of Reference,'' was made in 1960, and was one of the first audio-visual attempts at showing how your physical ``point of view,'' or frame of reference, necessarily alters both your perceptions and your observations of motion. The gentle humor and original demonstrations made a lasting impact on many audiences, and with its recent re-release as part of the AAPT Cinema Classics videodisc it is timely that we should review both the message and the methods of the film. An annotated script and photographs from the film are presented, followed by extension material on rotating frames which teachers may find appropriate for use in their classrooms: constructions, demonstrations, an example, and theory.

  3. Promoting International Cooperation and Public Acceptance in Utilizing Proton Accelerator Technology

    International Nuclear Information System (INIS)

    Choi, Byung Ho; Hahn, Bong Oh; Lee, Jae Hyung; Kim, Kyu Ryung; Joo, Po Kook; Kim, In Kyu; Kim, Hyun Joon; Noh, Seung Jeong

    2002-11-01

    Proton engineering's main tool will be a high power proton accelerator which is to be established within next 10 years in the frame of Proton engineering Frontier Project. It is necessary for public to understand the meaning and importance of the project so that Project activities such as site preparation can be efficiently completed. And, it is required to establish a sound plan of international cooperation, and to develop user program to establish domestic foundation in utilizing the accelerator. Along with public relations activities through newspapers and broadcasting, there were more than 20 times of project presentations requested by various local governments, universities, and scientific societies. which resulted in strong support of the project from various societies. Based on collected information through actual visits to and internet surveys on foreign accelerators, a recommendation of international cooperation scheme has been made to complement domestic technological weak points, and there were discussions with some foreign organizations for that purpose. Especially, KEK of Japan, IHEP of China and KAERI have been deliberating on planning detail cooperation programs in developing and utilizing accelerator among 3 countries Some research items related with NT/BT/IT and utilizing proton beam were planned to be implemented in the Project. And a user program implemented in the Project In order to be prepared for future use of the accelerator. In order to upbring junior researchers for future days, an accelerator summer school has been planned to be held annually inviting prominent foreign and domestic lecturers

  4. Comparison of 16-frame and 8-frame gated SPET imaging for determination of left ventricular volumes and ejection fraction

    International Nuclear Information System (INIS)

    Navare, Sachin M.; Liu, Yi-Hwa; Wackers, Frans J.T.

    2003-01-01

    Electrocardiographic (ECG) gated single-photon emission tomography (SPET) allows for simultaneous assessment of myocardial perfusion and left ventricular (LV) function. Presently 8-frame per cardiac cycle ECG gating of SPET images is standard. The aim of this study was to compare the effect of 8-frame and 16-frame gated SPET on measurements of LV volumes and to evaluate the effects of the presence of myocardial perfusion defects and of radiotracer dose administered on the calculation of LV volumes. A total of 86 patients underwent technetium-99m SPET myocardial perfusion imaging using 16-frame per cardiac cycle acquisition. Eight-frame gated SPET images were generated by summation of contiguous frames. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were calculated from the 16-frame and 8-frame data sets. The patients were divided into groups according to the administered dose of the radiotracer and the size of the perfusion defect. Results. Sixteen frame per cardiac cycle acquisition resulted in significantly larger EDV (122±72 ml vs 115±68 ml, P<0.0001), smaller ESV (64±58.6 ml vs 67.6±59.5 ml, P<0.0001), and higher LVEF (55.3%±18% vs 49%±17.4%, P<0.0001) as compared to 8-frame SPET imaging. This effect was seen regardless of whether a high or a low dose was administered and whether or not significant perfusion defects were present. This study shows that EDV, ESV and LVEF determined by 16-frame gated SPET are significantly different from those determined by 8-frame gated SPET. The radiotracer dose and perfusion defects do not affect estimation of LV parameters by 16-frame gated SPET. (orig.)

  5. Uniform Statistical Convergence on Time Scales

    Directory of Open Access Journals (Sweden)

    Yavuz Altin

    2014-01-01

    Full Text Available We will introduce the concept of m- and (λ,m-uniform density of a set and m- and (λ,m-uniform statistical convergence on an arbitrary time scale. However, we will define m-uniform Cauchy function on a time scale. Furthermore, some relations about these new notions are also obtained.

  6. serialising languages: satellite-framed, verb-framed or neither

    African Journals Online (AJOL)

    George Saad

    Figure 2: Verb-framed construction type (Slobin 2000: 109). 2 ... 2 An anonymous reviewer asks why we have replaced Talmy's conflation term “Ground” with ..... an S-language may predispose speakers to pay more linguistic attention to.

  7. Design of a 16T Nb3Sn twin dipole with a window-frame conductor layout

    International Nuclear Information System (INIS)

    van Oort, J.M.; Scanlan, R.M.

    1994-01-01

    A simplified design study of a 16T Nb 3 Sn twin bore accelerator dipole magnet is presented. The philosophy behind the study is to design a high field magnet with a coil structure optimized for a reasonable Lorentz-load and easy of construction. The coils are of the rectangular window-frame type with modular flat pancake windings, thus eliminating the need for complex coil return ends. The magnetic and structural design Is presented and a comparison is made with existing coil layouts for high field magnets

  8. Mixed-frame and stationary-frame repetitive control schemes for compensating typical load and grid harmonics

    DEFF Research Database (Denmark)

    Loh, P.; Tang, Y.; Blaabjerg, Frede

    2011-01-01

    In this study, repetitive current controllers operating in either the mixed or stationary frame are proposed for high-precision reference tracking and disturbance rejection of power converters. Both controllers use a proportional-resonant regulator in the stationary frame for regulating...... the positive- and negative-sequence fundamental currents, which are known to directly influence the flow of active and reactive power in most energy conversion systems. Moreover, for the tracking or compensation of harmonics, the controllers include a repetitive control path in either the synchronous...... or stationary frame, whose inherent feedback and feedforward structure is proven to resemble a bank of resonant filters in either reference frames. Unlike other existing controllers, the proposed repetitive controllers function by introducing multiple resonant peaks at only those harmonic frequencies typically...

  9. Controlling of density uniformity of polyacrylate foams

    International Nuclear Information System (INIS)

    Shan Wenwen; Yuan Baohe; Wang Yanhong; Xu Jiayun; Zhang Lin

    2010-01-01

    The density non-uniformity existing in most low-density foams will affect performance of the foams. The trimethylolpropane trimethacrylate (TMPTA) foam targets were prepared and controlling methods of the foams, density uniformity were explored together with its forming mechanism. It has been found that the UV-light with high intensity can improve the distribution uniformity of the free radicals induced by UV photons in the solvents, thus improve the density uniformity of the foams. In addition, container wall would influence the concentration distribution of the solution, which affects the density uniformity of the foams. Thus, the UV-light with high intensity was chosen together with polytetrafluoroethylene molds instead of glass molds to prepare the foams with the density non-uniformity less than 10%. β-ray detection technology was used to measure the density uniformity of the TMPTA foams with the density in the range of 10 to 100 mg · cm -3 , and the results show that the lower the foam density is, the worse the density uniformity is. (authors)

  10. Sparsity and spectral properties of dual frames

    DEFF Research Database (Denmark)

    Krahmer, Felix; Kutyniok, Gitta; Lemvig, Jakob

    2013-01-01

    We study sparsity and spectral properties of dual frames of a given finite frame. We show that any finite frame has a dual with no more than $n^2$ non-vanishing entries, where $n$ denotes the ambient dimension, and that for most frames no sparser dual is possible. Moreover, we derive an expressio...

  11. "Think" versus "feel" framing effects in persuasion.

    Science.gov (United States)

    Mayer, Nicole D; Tormala, Zakary L

    2010-04-01

    Three studies explored think ("I think . . . ") versus feel ("I feel . . . ") message framing effects on persuasion.The authors propose a matching hypothesis, suggesting that think framing will be more persuasive when the target attitude or message recipient is cognitively oriented, whereas feel framing will be more persuasive when the target attitude or message recipient is affectively oriented. Study 1 presented cognitively and affectively oriented individuals with a think- or feel-framed message. Study 2 primed cognitive or affective orientation and then presented a think- or feel-framed message. Study 3 presented male and female participants with an advertisement containing think- or feel-framed arguments. Results indicated that think (feel) framing was more persuasive when the target attitude or recipient was cognitively (affectively) oriented. Moreover, Study 2 demonstrated that this matching effect was mediated by processing fluency. Theoretical and practical implications are discussed.

  12. Thinking inside the frame: A framing analysis of the humanities in Danish print news media.

    Science.gov (United States)

    Knudsen, Sanne

    2017-11-01

    The humanities, the natural and social sciences all represent advanced and systematic knowledge production-and they all receive public funding for doing so. However, although the field of public understanding of science has been well established for decades, similar research attention has not been directed at the humanities. The purpose of this study is to argue the case for further research of public understanding of the humanities and to take a first step in that direction by presenting a study of the framing of the humanities in Danish print news media. Different framings of the humanities are analyzed. Despite the differences in the issue-specific frames, the generic framing of the humanities shared by most articles is as follows: 75% explicitly frame the humanities as deficit, while the remaining 25% are more neutral. Consequently, if newspapers constitute the only source of information concerning the humanities, newsreaders may not be much wiser in understanding what the humanities might be-but they will know that whatever the humanities is, it is broken and useless.

  13. Experimental and Simulated Characterization of a Beam Shaping Assembly for Accelerator- Based Boron Neutron Capture Therapy (AB-BNCT)

    International Nuclear Information System (INIS)

    Burlon, Alejandro A.; Valda, Alejandro A.; Girola, Santiago; Minsky, Daniel M.; Kreiner, Andres J.

    2010-01-01

    In the frame of the construction of a Tandem Electrostatic Quadrupole Accelerator facility devoted to the Accelerator-Based Boron Neutron Capture Therapy, a Beam Shaping Assembly has been characterized by means of Monte-Carlo simulations and measurements. The neutrons were generated via the 7 Li(p, n) 7 Be reaction by irradiating a thick LiF target with a 2.3 MeV proton beam delivered by the TANDAR accelerator at CNEA. The emerging neutron flux was measured by means of activation foils while the beam quality and directionality was evaluated by means of Monte Carlo simulations. The parameters show compliance with those suggested by IAEA. Finally, an improvement adding a beam collimator has been evaluated.

  14. Evaluation and the Framing of Race

    Science.gov (United States)

    House, Ernest R.

    2017-01-01

    Racial framing can have strong effects on programs, policies, and even evaluations. Racial framing developed as a justification for the exploitation of minorities and has been a primary causal factor in the persistence of racism. By being aware of its pattern, structure, origins, and how racial framing generates effects, we can significantly…

  15. 10 CFR 710.35 - Time frames.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Time frames. 710.35 Section 710.35 Energy DEPARTMENT OF... Matter or Special Nuclear Material Miscellaneous § 710.35 Time frames. Statements of time established for processing aspects of a case under this subpart are the agency's desired time frames in implementing the...

  16. 21 CFR 886.5842 - Spectacle frame.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Spectacle frame. 886.5842 Section 886.5842 Food... DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5842 Spectacle frame. (a) Identification. A spectacle frame is a device made of metal or plastic intended to hold prescription spectacle lenses worn by a...

  17. LEGO: A modular accelerator design code

    International Nuclear Information System (INIS)

    Cai, Y.; Donald, M.; Irwin, J.; Yan, Y.

    1997-08-01

    An object-oriented accelerator design code has been designed and implemented in a simple and modular fashion. It contains all major features of its predecessors: TRACY and DESPOT. All physics of single-particle dynamics is implemented based on the Hamiltonian in the local frame of the component. Components can be moved arbitrarily in the three dimensional space. Several symplectic integrators are used to approximate the integration of the Hamiltonian. A differential algebra class is introduced to extract a Taylor map up to arbitrary order. Analysis of optics is done in the same way both for the linear and nonlinear case. Currently, the code is used to design and simulate the lattices of the PEP-II. It will also be used for the commissioning

  18. Framing financial culture

    DEFF Research Database (Denmark)

    Just, Sine Nørholm; Mouton, Nicolaas T.O.

    2014-01-01

    between competing frames leads to the conclusion that this political “blame game” is related to struggles over how to define the scandal, how to conceptualize its causes, and policy recommendations. Banks may have lost the battle of “Liborgate,” but the war over the meaning of financial culture is far...... from over. Originality/value – The paper is theoretically and methodologically original in its combination of the theories of framing and stasis, and it provides analytical insights into how sense is made of financial culture in the wake of the financial crisis....

  19. Modern frame structure buildings

    Directory of Open Access Journals (Sweden)

    В. М. Першаков

    2013-07-01

    Full Text Available The article deals with the design, construction and implementation of reinforced concrete frame structures with span 18, 21 m for agricultural production buildings, hall-premises of public buildings and buildings of agricultural aviation. Structures are prefabricated frame buildings and have such advantages as large space inside the structure and lower cost compared with other facilities with same purpose

  20. Towards a poetics of the cinematographic frame

    Directory of Open Access Journals (Sweden)

    Des O'Rawe

    2011-05-01

    Full Text Available In delineating a poetics of the cinematographic frame, this essay presents a typology of framing styles, and demonstrates ways in which filmmakers use the frame as an expressive resource—and ways in which the frame uses them. The examples discussed are modernist in orientation, and each has a particular association with a city—its history, architecture, and cultural character. Although it is common practice to refer to various—especially, modernist—framing situations as instances of deframing, the essay also enquires into the problematic nature of this term, suggesting alternative visual and cinematographic contexts more amenable to the deconstructive implications of this term. As the boundaries between cinema and the other arts continue to converge and relations between frame, image, and screen become more complex, this essay offers a reassessment of some first principles of film language, especially the aesthetic integrity of the cinematographic frame.

  1. Inertial reference frames and gravitational forces

    International Nuclear Information System (INIS)

    Santavy, I.

    1981-01-01

    The connection between different definitions of inertial, i.e. fundamental, reference frames and the corresponding characterisation of gravitational fields by gravitational forces are considered from the point of view of their possible interpretation in university introductory courses. The introduction of a special class of reference frames, denoted 'mixed reference frames' is proposed and discussed. (author)

  2. 7 CFR 1006.61 - Computation of uniform prices.

    Science.gov (United States)

    2010-01-01

    ..., the market administrator shall compute a uniform butterfat price, a uniform skim milk price, and a... section. (b) Uniform skim milk price. The uniform skim milk price per hundredweight, rounded to the... paragraph (a) of this section times 3.5 pounds of butterfat; and (2) Multiply the uniform skim milk price...

  3. 7 CFR 1131.61 - Computation of uniform prices.

    Science.gov (United States)

    2010-01-01

    ..., the market administrator shall compute a uniform butterfat price, a uniform skim milk price, and a... section. (b) Uniform skim milk price. The uniform skim milk price per hundredweight, rounded to the... paragraph (a) of this section times 3.5 pounds of butterfat; and (2) Multiply the uniform skim milk price...

  4. 7 CFR 1007.61 - Computation of uniform prices.

    Science.gov (United States)

    2010-01-01

    ..., the market administrator shall compute a uniform butterfat price, a uniform skim milk price, and a... section. (b) Uniform skim milk price. The uniform skim milk price per hundredweight, rounded to the... paragraph (a) of this section times 3.5 pounds of butterfat; and (2) Multiply the uniform skim milk price...

  5. The effect of different feed restriction programs on reproductive performance, efficiency, frame size, and uniformity in broiler breeder hens.

    Science.gov (United States)

    de Beer, M; Coon, C N

    2007-09-01

    Two experiments were conducted to determine the effect of feed restriction programs on breeder reproductive performance. In experiment 1, every day (ED), skip-a-day (SK), 4-3, and 5-2 programs were compared. Diets did not differ, and feed intake was identical in all groups. Four hundred twenty pullets were reared on each program. At 21 wk, 80 breeders from each program were individually housed to record performance parameters. Body weight and frame size were larger in ED pullets than SK, 4-3, or 5-2 despite equal intakes. Hens fed ED reached sexual maturity at a younger age than other groups. Hens fed ED also produced more total and settable eggs than SK hens. Egg weight was heavier in 5-2 hens than in ED with 4-3 and SK intermediate. Efficiency of feed utilization was best in ED hens. In experiment 2 the same programs were tested, but pullets were reared to reach equal BW. One hundred seventy-five pullets were reared on each program, of which 60 were housed. Feed intake was greater for SK, 4-3, and 5-2 than ED pullets to reach the same BW. Frame size did not differ, indicating that BW was the cause of differences in experiment 1. In experiment 2, differences in performance were attenuated but not eliminated by feeding to reach equal BW, suggesting that metabolic factors aside from BW are altered by feeding programs. The 5-2 produced larger eggs than ED with the trend among programs being identical to that in experiment 1. These results suggest that metabolic changes such as increased lipogenesis or alterations in body composition may result in larger eggs in feeding programs that include off-feed days. Mortality, fertility, and hatchability were not affected by feeding programs in either experiment. Body composition analysis indicated the importance of total lean protein mass as a threshold for the onset of sexual maturity. Programs like SK are less efficient than ED and may result in reduced performance.

  6. Novel methods in the Particle-In-Cell accelerator Code-Framework Warp

    Energy Technology Data Exchange (ETDEWEB)

    Vay, J-L [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Grote, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cohen, R. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Friedman, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-12-26

    The Particle-In-Cell (PIC) Code-Framework Warp is being developed by the Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) to guide the development of accelerators that can deliver beams suitable for high-energy density experiments and implosion of inertial fusion capsules. It is also applied in various areas outside the Heavy Ion Fusion program to the study and design of existing and next-generation high-energy accelerators, including the study of electron cloud effects and laser wakefield acceleration for example. This study presents an overview of Warp's capabilities, summarizing recent original numerical methods that were developed by the HIFS-VNL (including PIC with adaptive mesh refinement, a large-timestep 'drift-Lorentz' mover for arbitrarily magnetized species, a relativistic Lorentz invariant leapfrog particle pusher, simulations in Lorentz-boosted frames, an electromagnetic solver with tunable numerical dispersion and efficient stride-based digital filtering), with special emphasis on the description of the mesh refinement capability. In addition, selected examples of the applications of the methods to the abovementioned fields are given.

  7. Symmetries of collective models in intrinsic frame

    International Nuclear Information System (INIS)

    Gozdz, A.; Pedrak, A.; Szulerecka, A.; Dobrowolski, A.; Dudek, J.

    2013-01-01

    In the paper a very general definition of intrinsic frame, by means of group theoretical methods, is introduced. It allows to analyze nuclear properties which are invariant in respect to the group which defines the intrinsic frame. For example, nuclear shape is a well determined feature in the intrinsic frame defined by the Euclidean group. It is shown that using of intrinsic frame gives an opportunity to consider intrinsic nuclear symmetries which are independent of symmetries observed in the laboratory frame. An importance of the notion of partial symmetries is emphasized. (author)

  8. An electrostatic scanning micromirror with diaphragm mirror plate and diamond-shaped reinforcement frame

    Science.gov (United States)

    Ji, Chang-Hyeon; Choi, Moongoo; Kim, Sang-Cheon; Lee, See-Hyung; Kim, Seong-Hyok; Yee, Youngjoo; Bu, Jong-Uk

    2006-05-01

    We present the design, fabrication and measurement results of a comb-driven electrostatic scanning micromirror. Instead of a conventional micromirror having uniform thickness across the entire reflective surface, a diaphragm mirror plate supported by an array of diamond-shaped frame structures is fabricated monolithically. The fabrication process is a simple sequence of silicon deep etch processes on both sides of the silicon-on-insulator (SOI) substrate without the substrate bonding process. The micromirror is fabricated on the device layer of the substrate. The mirror plate undergoes a rotational motion by an electrostatic force between the movable comb electrodes connected to the micromirror and stationary comb electrode formed on the handle wafer. A scanning micromirror with a 10 µm thick diaphragm mirror plate, having a planar dimension of 1.5 × 1.5 mm2, supported by an array of 110 µm thick rhombic support frames, was fabricated and tested. A mechanical deflection angle of 8.5° at a resonance frequency of 19.55 kHz and a pressure of 7 mTorr was obtained. A prototype of the raster scanning laser projection display system was developed using the fabricated micromirror as the horizontal scanner and a galvanomirror as the vertical scanner, respectively.

  9. 7 CFR 1005.61 - Computation of uniform prices.

    Science.gov (United States)

    2010-01-01

    ... month, the market administrator shall compute a uniform butterfat price, a uniform skim milk price, and...) and (a)(2) of this section. (b) Uniform skim milk price. The uniform skim milk price per hundredweight... paragraph (a) of this section times 3.5 pounds of butterfat; and (2) Multiply the uniform skim milk price...

  10. News framing and public opinion: A mediation analysis of framing effects on political attitudes

    NARCIS (Netherlands)

    Lecheler, S.K.; de Vreese, C.H.

    2012-01-01

    There is no satisfactory account of the psychological processes that mediate a news framing effect. Based on an experimental study (N = 1,537), this article presents a mediation analysis of a news framing effect on opinion, testing for two important mediation processes: belief importance and belief

  11. The light ion pulsed power induction accelerator for ETF

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Olson, R.E.; Olson, C.L.; Smith, D.L.; Bennett, L.F.

    1994-01-01

    Our Engineering Test Facility (ETF) driver concept is based on HERMES III and RHEPP technologies. Actually, it is a scaled-down version of the LMF design incorporating repetition rate capabilities of up to 10 Hz CW. The preconceptual design presented here provides 200-TW peak power to the ETF target during 10 ns, equal to 2-MJ total ion beam energy. Linear inductive voltage addition driving a self-magnetically insulated transmission line (MITL) is utilized to generate the 36-MV peak voltage needed for lithium ion beams. The ∼ 3-MA ion current is achieved by utilizing many accelerating modules in parallel. Since the current per module is relatively modest (∼300 kA), two-stage or one-stage extraction diodes can be utilized for the generation of singly charged lithium ions. The accelerating modules are arranged symmetrically around the fusion chamber in order to provide uniform irradiation onto the ETF target. In addition, the modules are fired in a programmed sequence in order to generate the optimum power pulse shape onto the target. This design utilizes RHEPP accelerator modules as the principal power source

  12. Some equalities and inequalities for fusion frames

    OpenAIRE

    Guo, Qianping; Leng, Jinsong; Li, Houbiao

    2016-01-01

    Fusion frames have some properties similar to those of frames in Hilbert spaces, but not all of their properties are similar. Some authors have established some equalities and inequalities for conventional frames. In this paper, we give some equalities and inequalities for fusion frames. Our results generalize and improve the remarkable results which have been obtained by Balan, Casazza and G?vruta etc.

  13. Does perceived risk influence the effects of message framing? Revisiting the link between prospect theory and message framing

    NARCIS (Netherlands)

    Riet, J.P. van 't; Cox, A.D.; Cox, D.; Zimet, G.D.; Bruijn, G.J. de; Putte, B. van den; Vries, H. de; Werrij, M.Q.; Ruiter, R.A.C.

    2016-01-01

    Health-promoting messages can be framed in terms of the beneficial consequences of healthy behaviour (gain-framed messages) or the detrimental consequences of unhealthy behaviour (loss-framed messages). An influential notion holds that the perceived risk associated with the recommended behaviour

  14. Gas dynamic improvement of the axial compressor design for reduction of the flow non-uniformity level

    Science.gov (United States)

    Matveev, V. N.; Baturin, O. V.; Kolmakova, D. A.; Popov, G. M.

    2017-01-01

    Circumferential nonuniformity of gas flow is one of the main problems in the gas turbine engine. Usually, the flow circumferential nonuniformity appears near the annular frame located in the flow passage of the engine. The presence of circumferential nonuniformity leads to the increased dynamic stresses in the blade rows and the blade damage. The goal of this research was to find the ways of the flow non-uniformity reduction, which would not require a fundamental changing of the engine design. A new method for reducing the circumferential nonuniformity of the gas flow was proposed that allows the prediction of the pressure peak values of the rotor blades without computationally expensive CFD calculations.

  15. Radiation from Accelerating Electric Charges: The Third Derivative of Position

    Science.gov (United States)

    Butterworth, Edward

    2010-03-01

    While some textbooks appear to suggest that acceleration of an electric charge is both a necessary and sufficient cause for the generation of electromagnetic radiation, the question has in fact had an intricate and involved history. In particular, the acceleration of a charge in hyperbolic motion, the behavior of a charge supported against a gravitational force (and its implications for the Equivalence Principle), and a charge accelerated by a workless constraint have been the subject of repeated investigation. The present paper examines specifically the manner in which the third derivative of position enters into the equations of motion, and the implications this has for the emission of radiation. Plass opens his review article with the statement that ``A fundamental property of all charged particles is that electromagnetic energy is radiated whenever they are accelerated'' (Plass 1961; emphasis mine). His treatment of the equations of motion, however, emphasizes the importance of the occurrence of the third derivative of position therein, present in linear motion only when the rate of acceleration is increasing or decreasing. There appears to be general agreement that the presence of a nonzero third derivative indicates that this charge is radiating; but does its absence preclude radiation? This question leads back to the issues of charges accelerated by a uniform gravitational field. We will examine the equations of motion as presented in Fulton & Rohrlich (1960), Plass (1961), Barut (1964), Teitelboim (1970) and Mo & Papas (1971) in the light of more recent literature in an attempt to clarify this question.

  16. On the generalized potential of inertial forces

    International Nuclear Information System (INIS)

    Siboni, S

    2009-01-01

    The generalized potential of the inertial forces acting on a holonomic system in an accelerated reference frame is derived in a way which admits a simple physical interpretation. It is shown that the generalized potential refers to all the inertial forces and, apart from the very special case of a uniformly rotating frame, it is impossible to distinguish a contribution to only the Coriolis force and a contribution pertaining to the residual, velocity-independent fictitious forces. Such an approach to the determination of the generalized potential of inertial forces may be helpful in introducing the topic of the generalized potential to advanced undergraduate and graduate students

  17. Parametric Study Of Window Frame Geometry

    DEFF Research Database (Denmark)

    Zajas, Jan Jakub; Heiselberg, Per

    2013-01-01

    This paper describes a parametric study on window frame geometry with the goal of designing frames with very good thermal properties. Three different parametric frame models are introduced, deseribed by a number of variables. In the first part of the study, a process of sensitivity analysis...... is conducted to determine which of the parameters describing the frame have the highest impact on its thermal performance. Afterwards, an optimization process is conducted on each frame in order to optimize the design with regard to three objectives: minimizing the thermal transmittance, maxim izing the net...... energy gain factor and minimizing the material use. Since the objectives contradiet each other, it was found that it is not possible to identifY a single solution that satisfies all these goals. lnstead, a compromise between the objectives has to be found....

  18. FishFrame

    DEFF Research Database (Denmark)

    Degel, Henrik; Jansen, Teunis

    2006-01-01

    . Development and test of software modules can be done once and reused by all. The biggest challenge in this is not technical – it is in organisation, coordination and trust. This challenge has been addressed by FishFrame - a web-based datawarehouse application. The “bottom-up” approach with maximum involvement...... of end users from as many labs and user groups as possible has been rather slow but quite successful in building international trust and cooperation around the system. This is mandatory prerequisites when our primary goal is not the programming project itself, but the creation of a tool that adds real...... value to users and in the end improves the way we work with our data. FishFrame version 4.2 is presented and the lessons learned from the process are discussed....

  19. Framing effect debiasing in medical decision making.

    Science.gov (United States)

    Almashat, Sammy; Ayotte, Brian; Edelstein, Barry; Margrett, Jennifer

    2008-04-01

    Numerous studies have demonstrated the robustness of the framing effect in a variety of contexts. The present study investigated the effects of a debiasing procedure designed to prevent the framing effect for young adults who made decisions based on hypothetical medical decision-making vignettes. The debiasing technique involved participants listing advantages and disadvantages of each treatment prior to making a choice. One hundred and two undergraduate students read a set of three medical treatment vignettes that presented information in terms of different outcome probabilities under either debiasing or control conditions. The framing effect was demonstrated by the control group in two of the three vignettes. The debiasing group successfully avoided the framing effect for both of these vignettes. These results further support previous findings of the framing effect as well as an effective debiasing technique. This study improved upon previous framing debiasing studies by including a control group and personal medical scenarios, as well as demonstrating debiasing in a framing condition in which the framing effect was demonstrated without a debiasing procedure. The findings suggest a relatively simple manipulation may circumvent the use of decision-making heuristics in patients.

  20. Effect of framing on adolescents' decision making.

    Science.gov (United States)

    Chien, Y C; Lin, C; Worthley, J

    1996-12-01

    92 young adolescents were tested using Tversky and Kahneman's (1981) decision problems for framing effects. A notable number of young adolescents tested were not influenced by the context of the decision problems, thus they selected the same response option for positively and negatively framed problems. Parallel information was not available in Tversky and Kahneman's study for adults because they used a between-subjects design. However, for present adolescents who selected different response options for different framing problems, the response pattern exhibited by them resembled the general pattern exhibited by the adults tested in Tversky and Kahneman's study-negative frames led them to accept risk to avoid certain loss; positive frames prevented them from risking what they were certain to gain. Boys and girls were similar in their susceptibility to framing effects as were honors students in mathematics as compared to nonhonors students. Although the positive vs negative framing only influenced some of the young adolescents tested in this study, because the influence was consistent, researchers and educators interested in adolescents' decisions involving risky choices might use framing principles to design and assess cognitive interventions for high-risk behaviors among young adolescents.