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Sample records for rapid distortion theory

  1. Spectral structure and linear mechanisms in a 'rapidly' distorted boundary layer

    Science.gov (United States)

    Diwan, Sourabh; Morrison, Jonathan

    2016-11-01

    A characteristic feature of a turbulent boundary layer (TBL) at high Reynolds numbers is the presence of coherent motions such as the 'large scale motions' and 'superstructures'. In this work we attempt to mimic such coherent motions and their spectral structure using a simplified experimental arrangement of a boundary layer flow over a flat plate subjected to grid-generated turbulence and/or localized patch of surface roughness. The velocity measurements done downstream of a grit roughness patch (in absence of grid turbulence) show that over a certain distance the energy spectrum of streamwise velocity fluctuations shows a bi-modal shape which resembles that found in a high-Re TBL. We also carry out experiments with both grid turbulence and grit roughness present and show that it is possible to 'synthesize' the structure of a TBL in the wall-normal direction, in the limited context of streamwise coherent motions, using the present experimental design. These results indicate that the predictions of the Rapid Distortion Theory (RDT) can be applied to the present case in a region close to the plate leading edge, and we examine the linearized effects of 'blocking' and 'shear' on turbulent fluctuations near the edge of the boundary layer and close to the wall in the framework of the RDT. We acknowledge financial support from EPSRC (Grant No. EP/1037938).

  2. Theories of cognitive distortions in sexual offending: what the current research tells us.

    Science.gov (United States)

    O Ciardha, Caoilte; Ward, Tony

    2013-01-01

    Cognitive distortions in sex offenders are specific or general beliefs/attitudes that violate commonly accepted norms of rationality that have been shown to be associated with the onset and maintenance of sexual offending. In this article, we describe the major theories that have been formulated to explain the role of distorted cognition in initiating and maintaining sexual offending. We evaluate each theory in light of a set of theory appraisal criteria and the available empirical research. Finally, we conclude by drawing together the results of this theory evaluation process and highlight the major implications for treatment and future research.

  3. Cognitive distortions in child molesters: a re-examination of key theories and research.

    Science.gov (United States)

    Gannon, Theresa A; Polaschek, Devon L L

    2006-12-01

    This review examines theory, research, and clinical practice relating to child molesters' cognitive distortions. First we review development of cognitive distortion theory and examine its epistemological usefulness. Then we critically evaluate available research evidence for current conceptualizations of cognitive distortions. This evaluation of the latest research suggests that clinical practice with child molesters has run ahead of scientific knowledge. We conclude that there is confusion about the exact nature of cognitive distortions, about the role that they play in sexual offending, and about what constitutes evidence of their existence. Although it seems likely that distorted cognition plays a role in some child molesters' offenses, our concern is that from a scientific standpoint, the majority of the research conducted cannot be used either to support or refute this view. We suggest that future research in this area should concentrate upon developing new methods and adapting methods established in other domains to enable measurement of child molesters' cognitive distortions in a more sophisticated way. Use of more diverse designs that better operationalize the construct of distorted cognition will ensure that future research (a) appreciably advances our knowledge of the scientific status of cognitive distortions in child molesters, and (b) promotes more effective empirically driven clinical practice with child molesters.

  4. The Extended Mind Theory of Cognitive Distortions in Sex Offenders

    Science.gov (United States)

    Ward, Tony

    2009-01-01

    An innovative theory of the nature of cognition, the extended mind theory (EMT), has emerged recently in the cognitive science literature. According to the EMT, the boundaries of the mind extend beyond the boundaries of skull and skin, into the world beyond. My aim in this paper is to consider the practical implications of the EMT for therapists…

  5. Simulation of Welding Distortions in Theory and Practice

    DEFF Research Database (Denmark)

    Birk-Sørensen, Martin; Kierkegaard, Henning

    1997-01-01

    . A finite element program has been used to simulate a one-sided fillet weld. The simulation agrees reasonably with the measurements. The analysis is divided into two tasks: temperature distribution and non-linear elalstic-plastic behaviour of the material. The temperature distribution is found by use......In the last few years the use of robot welding processes has increased significatnly. The programming of the robots has until now mainly focused on high efficiency, i.e.high torch rate time, and hence, minimising the inefficient "travelling" time. Together with developing high-performance welding...... due to cutting and welding and parlty in the form of dimensional variation due to human factors. Measurements have been made of the production line for assemblies. The measurements show that distortions related to the multirobot welding are a factor which can rather easily be controlled...

  6. The role of appraisal distortion, contempt, and morality in couple conflict: a grounded theory.

    Science.gov (United States)

    Whiting, Jason B

    2008-01-01

    A common goal of couples' therapy is to help individuals modify their view of each other and the relationship. Distorted views and appraisals contribute to conflict, and these can be manifest by use of rationalization or denial. This study explored appraisal distortion as an evaluative and moral process that occurs during partner conflict, particularly when it becomes contemptuous and aggressive. Using a philosophical base that is grounded in the ethical relationship, a model of appraisal distortion and couple conflict was created using constructivist grounded theory methods. The theoretical concepts derived from the data show relationships between one's relational stance, appraisal distortion, and verbal and physical aggression. This model implies that helping individuals take responsibility for appraisals is important in treating conflict.

  7. Moral judgment, cognitive distortions and implicit theories in young sex offenders

    NARCIS (Netherlands)

    van Vugt, E.; Hendriks, J.; Stams, G.J.; van Exter, F.; Bijleveld, C.; van der Laan, P.; Asscher, J.

    2011-01-01

    This study focused on moral judgment, cognitive distortions and implicit theories in 77 young sex offenders of whom 56 were child abusers and 21 were peer abusers. The sociomoral reflection measure- short form (SRM-SF) was used to assess moral judgment, and was extended with questions about sexual

  8. Current Cognitive Distortion Theory and Research: An Internalist Approach to Cognition

    Science.gov (United States)

    Gannon, Theresa A.

    2009-01-01

    This review examines contemporary cognitive distortion theory and research relating to sexual offenders. In particular, this review highlights that researchers--to date--have tended to adopt an internalist approach to sexual offenders' cognition which views offence-supportive cognitive activity as occurring solely within the mind. This review…

  9. Solid modeling and applications rapid prototyping, CAD and CAE theory

    CERN Document Server

    Um, Dugan

    2016-01-01

    The lessons in this fundamental text equip students with the theory of Computer Assisted Design (CAD), Computer Assisted Engineering (CAE), the essentials of Rapid Prototyping, as well as practical skills needed to apply this understanding in real world design and manufacturing settings. The book includes three main areas: CAD, CAE, and Rapid Prototyping, each enriched with numerous examples and exercises. In the CAD section, Professor Um outlines the basic concept of geometric modeling, Hermite and Bezier Spline curves theory, and 3-dimensional surface theories as well as rendering theory. The CAE section explores mesh generation theory, matrix notion for FEM, the stiffness method, and truss Equations. And in Rapid Prototyping, the author illustrates stereo lithographic theory and introduces popular modern RP technologies. Solid Modeling and Applications: Rapid Prototyping, CAD and CAE Theory is ideal for university students in various engineering disciplines as well as design engineers involved in product...

  10. Using Graph Theory and a Plenoptic Sensor to Recognize Phase Distortions of a Laser Beam

    CERN Document Server

    Wu, Chensheng; Davis, Christopher C

    2015-01-01

    Atmospheric turbulence causes fluctuations in the local refractive index of air that accumulatively disturb a wave's phase and amplitude distribution as it propagates. This impairs the effective range of laser weapons as well as the performance of free space optical (FSO) communication systems. Adaptive optics (AO) can be applied to effectively correct wavefront distortions in weak turbulence situations. However, in strong or deep turbulence, where scintillation and beam breakup are common phenomena, traditional wavefront sensing techniques such as the use of Shack-Hartmann sensors lead to incorrect results. Consequently, the performance of AO systems will be greatly compromised. We propose a new approach that can determine the major phase distortions in a beam instantaneously and guide an AO device to compensate for the phase distortion in a few iterations. In our approach, we use a plenoptic wavefront sensor to image the distorted beam into its 4D phase space. A fast reconstruction algorithm based on graph ...

  11. Cognitive distortions in child sex offenders: an overview of theory, research & practice.

    Science.gov (United States)

    Navathe, Shruti; Ward, Tony; Gannon, Theresa

    2008-01-01

    A great deal of clinical and research attention has been paid to understanding and explaining child sex offenders' social cognition. Cognitive distortions have been implicated as a core feature of child sex offenders' offense supportive cognition. The primary aim of this paper is to critically evaluate the phenomenon of cognitive distortions as currently understood with respect to child sex offenders: it reviews the theoretical and research literature and highlights the implications for clinical practice.

  12. Whole Earth Telescope discovery of a strongly distorted quadrupole pulsation in the largest amplitude rapidly oscillating Ap star

    Science.gov (United States)

    Holdsworth, Daniel L.; Kurtz, D. W.; Saio, H.; Provencal, J. L.; Letarte, B.; Sefako, R. R.; Petit, V.; Smalley, B.; Thomsen, H.; Fletcher, C. L.

    2018-01-01

    We present a new analysis of the rapidly oscillating Ap (roAp) star, 2MASS J19400781 - 4420093 (J1940; V = 13.1). The star was discovered using SuperWASP broad-band photometry to have a frequency of 176.39 d-1 (2041.55 μHz; P = 8.2 min; Holdsworth et al. 2014a) and is shown here to have a peak-to-peak amplitude of 34 mmag. J1940 has been observed during three seasons at the South African Astronomical Observatory, and has been the target of a Whole Earth Telescope campaign. The observations reveal that J1940 pulsates in a distorted quadrupole mode with unusual pulsational phase variations. A higher signal-to-noise ratio spectrum has been obtained since J1940's first announcement, which allows us to classify the star as A7 Vp Eu(Cr). The observing campaigns presented here reveal no pulsations other than the initially detected frequency. We model the pulsation in J1940 and conclude that the pulsation is distorted by a magnetic field of strength 1.5 kG. A difference in the times of rotational maximum light and pulsation maximum suggests a significant offset between the spots and pulsation axis, as can be seen in roAp stars.

  13. Distorted wave theories for dressed-ion-atom collisions with GSZ projectile potentials

    Energy Technology Data Exchange (ETDEWEB)

    Monti, J M; Rivarola, R D [Instituto de Fisica Rosario (CONICET-UNR) and Facultad de Ciencias Exactas, IngenierIa y Agrimensura, Universidad Nacional de Rosario, Avenida Pellegrini 250, 2000 Rosario (Argentina); Fainstein, P D, E-mail: monti@ifir-conicet.gov.ar [Comision Nacional de EnergIa Atomica, Centro Atomico Bariloche, 8400 San Carlos de Bariloche (Argentina)

    2011-10-14

    The continuum distorted wave and the continuum distorted wave-eikonal initial state approximations for electron emission in ion-atom collisions are generalized to the case of dressed projectiles. The interaction between the dressed projectile and the active electron is represented by the analytic Green-Sellin-Zachor (GSZ) potential. Doubly differential cross sections as a function of the emitted electron energy and angle are computed. The region of the binary encounter peak is analysed in detail. Interference structures appear in agreement with the experimental data and are interpreted as arising from the coherent interference between short- and long-range scattering amplitudes.

  14. Medium energy nucleon-nucleus scattering theory by semi-classical distorted wave approximation

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, Kazuyuki [Kyushu Univ., Fukuoka (Japan)

    1998-07-01

    The semiclassical distorted wave model (SCDW) is one of the quantum mechanical models for nucleon inelastic and charge exchange scattering at intermediate energies. SCDW can reproduce the double differential inclusive cross sections for multi-step direct processes quite well in the angular and outgoing energy regions where the model is expected to work. But the model hitherto assumed on-the-energy-shell (on-shell) nucleon-nucleon scattering in the nucleus, neglecting the difference in the distorting potentials for the incoming and the outgoing particles and also the Q-value in the case of (p,n) reactions. There had also been a problem in the treatment of the exchange of colliding nucleons. Now we modify the model to overcome those problems and put SCDW on sounder theoretical foundations. The modification results in slight reduction (increase) of double differential cross sections at forward (backward) angles. We also examine the effect of the in-medium modification of N-N cross sections in SCDW and find it small. A remedy of the disagreement at very small and large angles in terms of the Wigner transform of the single particle density matrix is also discussed. This improvement gives very promising results. (author)

  15. Modeling Atmospheric Turbulence via Rapid Distortion Theory: Spectral Tensor of Velocity and Buoyancy

    DEFF Research Database (Denmark)

    Chougule, Abhijit S.; Mann, Jakob; Kelly, Mark C.

    2017-01-01

    the eddy lifetime parameterization of Mann to make the model stationary. The buoyant spectral tensor model is driven via five parameters: the viscous dissipation rate epsilon, length scale of energy-containing eddies L, a turbulence anisotropy parameter Gamma, gradient Richardson number (Ri) representing...

  16. Lattice distortions in the FeCoNiCrMn high entropy alloy studied by theory and experiment

    NARCIS (Netherlands)

    Oh, H.S.; Ma, D; Leyson, G.P.; Grabowski, B; Park, E.S.; Kormann, F.H.W.; Raabe, D.

    2016-01-01

    Lattice distortions constitute one of the main features characterizing high entropy alloys. Local lattice distortions have, however, only rarely been investigated in these multi-component alloys. We, therefore, employ a combined theoretical electronic structure and experimental approach to study the

  17. Distortion compensator

    NARCIS (Netherlands)

    Sakamoto, K.; Nauta, Bram

    2013-01-01

    PROBLEM TO BE SOLVED: To improve distortion compensation accuracy of a power amplifier. :SOLUTION: An LMS algorithm using a feedback signal that is an output signal of a power amplifier 1 input via an attenuator 15 and pseudorandom data calculates a delay of an input signal to the power amplifier 1.

  18. Distortion Compensator

    NARCIS (Netherlands)

    Sakamoto, K.; Nauta, Bram

    2013-01-01

    PROBLEM TO BE SOLVED: To improve distortion compensation accuracy of a power amplifier. ;SOLUTION: An LMS algorithm using a feedback signal that is an output signal of a power amplifier 1 input via an attenuator 17 and pseudorandom data calculates a delay of an input signal to the power amplifier 1

  19. Distortion Compensator

    NARCIS (Netherlands)

    Sakamoto, K.; Nauta, Bram

    2013-01-01

    PROBLEM TO BE SOLVED: To improve the accuracy of distortion compensation of a power amplifier. SOLUTION: An LMS algorithm using a feedback signal that is an output signal of a power amplifier 1 input via an attenuator 17 and pseudorandom data calculates a delay of an input signal to the power

  20. Strongly nonlinear theory of rapid solidification near absolute stability

    Science.gov (United States)

    Kowal, Katarzyna N.; Altieri, Anthony L.; Davis, Stephen H.

    2017-10-01

    We investigate the nonlinear evolution of the morphological deformation of a solid-liquid interface of a binary melt under rapid solidification conditions near two absolute stability limits. The first of these involves the complete stabilization of the system to cellular instabilities as a result of large enough surface energy. We derive nonlinear evolution equations in several limits in this scenario and investigate the effect of interfacial disequilibrium on the nonlinear deformations that arise. In contrast to the morphological stability problem in equilibrium, in which only cellular instabilities appear and only one absolute stability boundary exists, in disequilibrium the system is prone to oscillatory instabilities and a second absolute stability boundary involving attachment kinetics arises. Large enough attachment kinetics stabilize the oscillatory instabilities. We derive a nonlinear evolution equation to describe the nonlinear development of the solid-liquid interface near this oscillatory absolute stability limit. We find that strong asymmetries develop with time. For uniform oscillations, the evolution equation for the interface reduces to the simple form f''+(βf')2+f =0 , where β is the disequilibrium parameter. Lastly, we investigate a distinguished limit near both absolute stability limits in which the system is prone to both cellular and oscillatory instabilities and derive a nonlinear evolution equation that captures the nonlinear deformations in this limit. Common to all these scenarios is the emergence of larger asymmetries in the resulting shapes of the solid-liquid interface with greater departures from equilibrium and larger morphological numbers. The disturbances additionally sharpen near the oscillatory absolute stability boundary, where the interface becomes deep-rooted. The oscillations are time-periodic only for small-enough initial amplitudes and their frequency depends on a single combination of physical parameters, including the

  1. The Perceptual Distortion of Height in Intercollegiate Debate.

    Science.gov (United States)

    Hensley, Wayne E.; Angoli, Marilyn

    Both balance and reinforcement theories were used in an examination of the perceptual distortion of height among 146 college debaters. Balance theory predicted that losers would distort winners' heights upward; reinforcement theory predicted that winners would distort losers' heights upward. The results confirmed both predictions. The possibility…

  2. Fractality of sensations and the brain health: the theory linking neurodegenerative disorder with distortion of spatial and temporal scale-invariance and fractal complexity of the visible world

    Science.gov (United States)

    Zueva, Marina V.

    2015-01-01

    The theory that ties normal functioning and pathology of the brain and visual system with the spatial–temporal structure of the visual and other sensory stimuli is described for the first time in the present study. The deficit of fractal complexity of environmental influences can lead to the distortion of fractal complexity in the visual pathways of the brain and abnormalities of development or aging. The use of fractal light stimuli and fractal stimuli of other modalities can help to restore the functions of the brain, particularly in the elderly and in patients with neurodegenerative disorders or amblyopia. Non-linear dynamics of these physiological processes have a strong base of evidence, which is seen in the impaired fractal regulation of rhythmic activity in aged and diseased brains. From birth to old age, we live in a non-linear world, in which objects and processes with the properties of fractality and non-linearity surround us. Against this background, the evolution of man took place and all periods of life unfolded. Works of art created by man may also have fractal properties. The positive influence of music on cognitive functions is well-known. Insufficiency of sensory experience is believed to play a crucial role in the pathogenesis of amblyopia and age-dependent diseases. The brain is very plastic in its early development, and the plasticity decreases throughout life. However, several studies showed the possibility to reactivate the adult’s neuroplasticity in a variety of ways. We propose that a non-linear structure of sensory information on many spatial and temporal scales is crucial to the brain health and fractal regulation of physiological rhythms. Theoretical substantiation of the author’s theory is presented. Possible applications and the future research that can experimentally confirm or refute the theoretical concept are considered. PMID:26236232

  3. Oscillation modes of rapidly rotating neutron stars in scalar-tensor theories of gravity

    Science.gov (United States)

    Yazadjiev, Stoytcho S.; Doneva, Daniela D.; Kokkotas, Kostas D.

    2017-09-01

    We perform the first study of the oscillation frequencies of rapidly rotating neutron stars in alternative theories of gravity, focusing mainly on the fundamental f modes. We concentrated on a particular class of alternative theories—the (massive) scalar-tensor theories. The generalization to rapid rotation is important because on one hand the rapid rotation can magnify the deviations from general relativity compared to the static case and on the other hand some of the most efficient emitters of gravitational radiation, such as the binary neutron star merger remnants, are supposed to be rotating close to their Kepler (mass-shedding) limits shortly after their formation. We have constructed several sequences of models starting from the nonrotating case and reaching up to the Kepler limit, with different values of the scalar-tensor theory coupling constant and the scalar field mass. The results show that the deviations from pure Einstein's theory can be significant, especially in the case of nonzero scalar field mass. An important property of the oscillation modes of rapidly rotating stars is that they can become secularly unstable due to the emission of gravitational radiation, the so-called Chandrasekhar-Friedman-Schutz instability. Such unstable modes are efficient emitters of gravitational radiation. Our studies show that the inclusion of a nonzero scalar field would decrease the threshold value of the normalized angular momentum where this instability starts to operate, but the growth time of the instability seems to be increased compared to pure general relativity.

  4. Distortional eigenmodes and solutions for thin-walled beams

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Jönsson, Jeppe

    2011-01-01

    This paper presents a generalization of the classic theory for thin-walled beams by including distortional displacements. A condensed presentation of the novel finite-elementbased displacement approach in [1,2] is given, where specific distortional displacement fields, which decouple the differen......This paper presents a generalization of the classic theory for thin-walled beams by including distortional displacements. A condensed presentation of the novel finite-elementbased displacement approach in [1,2] is given, where specific distortional displacement fields, which decouple...... the differential equations for generalized beam theory (GBT), are determined via a semi-discretization procedure. The distortional displacement fields are found as solutions to a distortional homogeneous eigenvalue problem which produce distortional displacement eigenmodes. Using the distortional modal matrix...

  5. Rapid Construction of Stable Infectious Full-Length cDNA Clone of Papaya Leaf Distortion Mosaic Virus Using In-Fusion Cloning.

    Science.gov (United States)

    Tuo, Decai; Shen, Wentao; Yan, Pu; Li, Xiaoying; Zhou, Peng

    2015-12-01

    Papaya leaf distortion mosaic virus (PLDMV) is becoming a threat to papaya and transgenic papaya resistant to the related pathogen, papaya ringspot virus (PRSV). The generation of infectious viral clones is an essential step for reverse-genetics studies of viral gene function and cross-protection. In this study, a sequence- and ligation-independent cloning system, the In-Fusion(®) Cloning Kit (Clontech, Mountain View, CA, USA), was used to construct intron-less or intron-containing full-length cDNA clones of the isolate PLDMV-DF, with the simultaneous scarless assembly of multiple viral and intron fragments into a plasmid vector in a single reaction. The intron-containing full-length cDNA clone of PLDMV-DF was stably propagated in Escherichia coli. In vitro intron-containing transcripts were processed and spliced into biologically active intron-less transcripts following mechanical inoculation and then initiated systemic infections in Carica papaya L. seedlings, which developed similar symptoms to those caused by the wild-type virus. However, no infectivity was detected when the plants were inoculated with RNA transcripts from the intron-less construct because the instability of the viral cDNA clone in bacterial cells caused a non-sense or deletion mutation of the genomic sequence of PLDMV-DF. To our knowledge, this is the first report of the construction of an infectious full-length cDNA clone of PLDMV and the splicing of intron-containing transcripts following mechanical inoculation. In-Fusion cloning shortens the construction time from months to days. Therefore, it is a faster, more flexible, and more efficient method than the traditional multistep restriction enzyme-mediated subcloning procedure.

  6. Rapid Construction of Stable Infectious Full-Length cDNA Clone of Papaya Leaf Distortion Mosaic Virus Using In-Fusion Cloning

    Directory of Open Access Journals (Sweden)

    Decai Tuo

    2015-12-01

    Full Text Available Papaya leaf distortion mosaic virus (PLDMV is becoming a threat to papaya and transgenic papaya resistant to the related pathogen, papaya ringspot virus (PRSV. The generation of infectious viral clones is an essential step for reverse-genetics studies of viral gene function and cross-protection. In this study, a sequence- and ligation-independent cloning system, the In-Fusion® Cloning Kit (Clontech, Mountain View, CA, USA, was used to construct intron-less or intron-containing full-length cDNA clones of the isolate PLDMV-DF, with the simultaneous scarless assembly of multiple viral and intron fragments into a plasmid vector in a single reaction. The intron-containing full-length cDNA clone of PLDMV-DF was stably propagated in Escherichia coli. In vitro intron-containing transcripts were processed and spliced into biologically active intron-less transcripts following mechanical inoculation and then initiated systemic infections in Carica papaya L. seedlings, which developed similar symptoms to those caused by the wild-type virus. However, no infectivity was detected when the plants were inoculated with RNA transcripts from the intron-less construct because the instability of the viral cDNA clone in bacterial cells caused a non-sense or deletion mutation of the genomic sequence of PLDMV-DF. To our knowledge, this is the first report of the construction of an infectious full-length cDNA clone of PLDMV and the splicing of intron-containing transcripts following mechanical inoculation. In-Fusion cloning shortens the construction time from months to days. Therefore, it is a faster, more flexible, and more efficient method than the traditional multistep restriction enzyme-mediated subcloning procedure.

  7. Rate-distortion analysis of dead-zone plus uniform threshold scalar quantization and its application--part I: fundamental theory.

    Science.gov (United States)

    Sun, Jun; Duan, Yizhou; Li, Jiangtao; Liu, Jiaying; Guo, Zongming

    2013-01-01

    This paper provides a systematic rate-distortion (R-D) analysis of the dead-zone plus uniform threshold scalar quantization (DZ+UTSQ) with nearly uniform reconstruction quantization (NURQ) for generalized Gaussian distribution (GGD), which consists of two aspects: R-D performance analysis and R-D modeling. In R-D performance analysis, we first derive the preliminary constraint of optimum entropy-constrained DZ+UTSQ/NURQ for GGD, under which the property of the GGD distortion-rate (D-R) function is elucidated. Then for the GGD source of actual transform coefficients, the refined constraint and precise conditions of optimum DZ+UTSQ/NURQ are rigorously deduced in the real coding bit rate range, and efficient DZ+UTSQ/NURQ design criteria are proposed to reasonably simplify the utilization of effective quantizers in practice. In R-D modeling, inspired by R-D performance analysis, the D-R function is first developed, followed by the novel rate-quantization (R-Q) and distortion-quantization (D-Q) models derived using analytical and heuristic methods. The D-R, R-Q, and D-Q models form the source model describing the relationship between the rate, distortion, and quantization steps. One application of the proposed source model is the effective two-pass VBR coding algorithm design on an encoder of H.264/AVC reference software, which achieves constant video quality and desirable rate control accuracy.

  8. Cognitive Distortions, Humor Styles, and Depression.

    Science.gov (United States)

    Rnic, Katerina; Dozois, David J A; Martin, Rod A

    2016-08-01

    Cognitive distortions are negative biases in thinking that are theorized to represent vulnerability factors for depression and dysphoria. Despite the emphasis placed on cognitive distortions in the context of cognitive behavioural theory and practice, a paucity of research has examined the mechanisms through which they impact depressive symptomatology. Both adaptive and maladaptive styles of humor represent coping strategies that may mediate the relation between cognitive distortions and depressive symptoms. The current study examined the correlations between the frequency and impact of cognitive distortions across both social and achievement-related contexts and types of humor. Cognitive distortions were associated with reduced use of adaptive Affiliative and Self-Enhancing humor styles and increased use of maladaptive Aggressive and Self-Defeating humor. Reduced use of Self-Enhancing humor mediated the relationship between most types of cognitive distortions and depressed mood, indicating that distorted negative thinking may interfere with an individual's ability to adopt a humorous and cheerful outlook on life (i.e., use Self-Enhancing humor) as a way of regulating emotions and coping with stress, thereby resulting in elevated depressive symptoms. Similarly, Self-Defeating humor mediated the association of the social impact of cognitive distortions with depression, such that this humor style may be used as a coping strategy for dealing with distorted thinking that ultimately backfires and results in increased dysphoria.

  9. Cognitive Distortions, Humor Styles, and Depression

    Directory of Open Access Journals (Sweden)

    Katerina Rnic

    2016-08-01

    Full Text Available Cognitive distortions are negative biases in thinking that are theorized to represent vulnerability factors for depression and dysphoria. Despite the emphasis placed on cognitive distortions in the context of cognitive behavioural theory and practice, a paucity of research has examined the mechanisms through which they impact depressive symptomatology. Both adaptive and maladaptive styles of humor represent coping strategies that may mediate the relation between cognitive distortions and depressive symptoms. The current study examined the correlations between the frequency and impact of cognitive distortions across both social and achievement-related contexts and types of humor. Cognitive distortions were associated with reduced use of adaptive Affiliative and Self-Enhancing humor styles and increased use of maladaptive Aggressive and Self-Defeating humor. Reduced use of Self-Enhancing humor mediated the relationship between most types of cognitive distortions and depressed mood, indicating that distorted negative thinking may interfere with an individual’s ability to adopt a humorous and cheerful outlook on life (i.e., use Self-Enhancing humor as a way of regulating emotions and coping with stress, thereby resulting in elevated depressive symptoms. Similarly, Self-Defeating humor mediated the association of the social impact of cognitive distortions with depression, such that this humor style may be used as a coping strategy for dealing with distorted thinking that ultimately backfires and results in increased dysphoria.

  10. Sudden distortion of turbulence at a forest edge

    Science.gov (United States)

    Mann, J.; Dellwik, E.

    2014-06-01

    Dellwik et al. (2013) presented data from a forest edge experiment based on two meteorological towers instrumented with sonic anemometers. The experiment was performed at a dense edge of the Tromnæs Forest, which is a 24 m tall mature beech stand on the island Falster, Denmark. The topography at the site is flat. The towers were placed approximately 1.5 canopy heights upwind and downwind of the edge, respectively, and were two canopy heights tall. For near-neutral, near-perpendicular flow towards the edge, one finding concerned that although the wind speed gradients were similar before and after the edge, the momentum flux was strongly reduced above the canopy. This is contrary to the results by standard Reynolds' averaged Navier-Stokes models that predict an overshoot of the momentum flux. Further, a reduction of the vertical variance of the flow was largely compensated by an increase in the lateral variance, whereas the streamwise variance remained approximately constant. This result is in contrast to the predictions by homogeneous rapid distortion theory. We apply and develop an alternative framework based on inhomogeneous rapid distortion theory, also called blocking, in combination with the turbulence model by Mann (1994), and investigate whether this model can predict the observed changes of the flow. The presented results are relevant for understanding the rapid changes of turbulence in the heterogeneous landscape.

  11. Distortion Control during Welding

    OpenAIRE

    Akbari Pazooki, A.M.

    2014-01-01

    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ methods to control welding distortion. In these methods local heating and/or cooling strategies are applied during welding. Additional heating and/or cooling sources can be implemented either stationa...

  12. [An improved low spectral distortion PCA fusion method].

    Science.gov (United States)

    Peng, Shi; Zhang, Ai-Wu; Li, Han-Lun; Hu, Shao-Xing; Meng, Xian-Gang; Sun, Wei-Dong

    2013-10-01

    Aiming at the spectral distortion produced in PCA fusion process, the present paper proposes an improved low spectral distortion PCA fusion method. This method uses NCUT (normalized cut) image segmentation algorithm to make a complex hyperspectral remote sensing image into multiple sub-images for increasing the separability of samples, which can weaken the spectral distortions of traditional PCA fusion; Pixels similarity weighting matrix and masks were produced by using graph theory and clustering theory. These masks are used to cut the hyperspectral image and high-resolution image into some sub-region objects. All corresponding sub-region objects between the hyperspectral image and high-resolution image are fused by using PCA method, and all sub-regional integration results are spliced together to produce a new image. In the experiment, Hyperion hyperspectral data and Rapid Eye data were used. And the experiment result shows that the proposed method has the same ability to enhance spatial resolution and greater ability to improve spectral fidelity performance.

  13. Incorporating rapid neocortical learning of new schema-consistent information into complementary learning systems theory.

    Science.gov (United States)

    McClelland, James L

    2013-11-01

    The complementary learning systems theory of the roles of hippocampus and neocortex (McClelland, McNaughton, & O'Reilly, 1995) holds that the rapid integration of arbitrary new information into neocortical structures is avoided to prevent catastrophic interference with structured knowledge representations stored in synaptic connections among neocortical neurons. Recent studies (Tse et al., 2007, 2011) showed that neocortical circuits can rapidly acquire new associations that are consistent with prior knowledge. The findings challenge the complementary learning systems theory as previously presented. However, new simulations extending those reported in McClelland et al. (1995) show that new information that is consistent with knowledge previously acquired by a putatively cortexlike artificial neural network can be learned rapidly and without interfering with existing knowledge; it is when inconsistent new knowledge is acquired quickly that catastrophic interference ensues. Several important features of the findings of Tse et al. (2007, 2011) are captured in these simulations, indicating that the neural network model used in McClelland et al. has characteristics in common with neocortical learning mechanisms. An additional simulation generalizes beyond the network model previously used, showing how the rate of change of cortical connections can depend on prior knowledge in an arguably more biologically plausible network architecture. In sum, the findings of Tse et al. are fully consistent with the idea that hippocampus and neocortex are complementary learning systems. Taken together, these findings and the simulations reported here advance our knowledge by bringing out the role of consistency of new experience with existing knowledge and demonstrating that the rate of change of connections in real and artificial neural networks can be strongly prior-knowledge dependent. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  14. Distortional Modes of Thin-Walled Beams

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Andreassen, Michael Joachim

    2009-01-01

    The classic thin-walled beam theory for open and closed cross-sections can be generalized by including distortional displacement modes. The introduction of additional displacement modes leads to coupled differential equations, which seems to have prohibited the use of exact shape functions...... in the modelling of coupled torsion and distortion. However, if the distortional displacement modes are chosen as those which decouple the differential equations as in non proportionally damped modal dynamic analysis then it may be possible to use exact shape functions and perform analysis on a reduced problem....... In the recently developed generalized beam theory (GBT) the natural distortional displacement modes are determined on the basis of a quadratic eigenvalue problem. However, as in linear modal dynamic analysis of proportionally damped structures this problem has been solved approximately using linear eigenvalue...

  15. Distortion Control during Welding

    NARCIS (Netherlands)

    Akbari Pazooki, A.M.

    2014-01-01

    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ

  16. Optical Anisotropy of Topologically Distorted Semiconductor Nanocrystals.

    Science.gov (United States)

    Baimuratov, Anvar S; Pereziabova, Tatiana P; Zhu, Weiren; Leonov, Mikhail Yu; Baranov, Alexander V; Fedorov, Anatoly V; Rukhlenko, Ivan D

    2017-09-13

    Engineering nanostructured optical materials via the purposeful distortion of their constituent nanocrystals requires the knowledge of how various distortions affect the nanocrystals' electronic subsystem and its interaction with light. We use the geometric theory of defects in solids to calculate the linear permittivity tensor of semiconductor nanocrystals whose crystal lattice is arbitrarily distorted by imperfections or strains. The result is then employed to systematically analyze the optical properties of nanocrystals with spatial dispersion caused by screw dislocations and Eshelby twists. We demonstrate that Eshelby twists create gyrotropy in nanocrystals made of isotropic semiconductors whereas screw dislocations can produce it only if the nanocrystal material itself is inherently anisotropic. We also show that the dependence of circular dichroism spectrum on the aspect ratio of dislocation-distorted semiconductor nanorods allows resonant enhancing their optical activity (at least by a factor of 2) and creating highly optically active nanomaterials.

  17. Distortions in memory for visual displays

    Science.gov (United States)

    Tversky, Barbara

    1989-01-01

    Systematic errors in perception and memory present a challenge to theories of perception and memory and to applied psychologists interested in overcoming them as well. A number of systematic errors in memory for maps and graphs are reviewed, and they are accounted for by an analysis of the perceptual processing presumed to occur in comprehension of maps and graphs. Visual stimuli, like verbal stimuli, are organized in comprehension and memory. For visual stimuli, the organization is a consequence of perceptual processing, which is bottom-up or data-driven in its earlier stages, but top-down and affected by conceptual knowledge later on. Segregation of figure from ground is an early process, and figure recognition later; for both, symmetry is a rapidly detected and ecologically valid cue. Once isolated, figures are organized relative to one another and relative to a frame of reference. Both perceptual (e.g., salience) and conceptual factors (e.g., significance) seem likely to affect selection of a reference frame. Consistent with the analysis, subjects perceived and remembered curves in graphs and rivers in maps as more symmetric than they actually were. Symmetry, useful for detecting and recognizing figures, distorts map and graph figures alike. Top-down processes also seem to operate in that calling attention to the symmetry vs. asymmetry of a slightly asymmetric curve yielded memory errors in the direction of the description. Conceptual frame of reference effects were demonstrated in memory for lines embedded in graphs. In earlier work, the orientation of map figures was distorted in memory toward horizontal or vertical. In recent work, graph lines, but not map lines, were remembered as closer to an imaginary 45 deg line than they had been. Reference frames are determined by both perceptual and conceptual factors, leading to selection of the canonical axes as a reference frame in maps, but selection of the imaginary 45 deg as a reference frame in graphs.

  18. The Lattice Compatibility Theory LCT: Physical and Chemical Arguments from the Growth Behavior of Doped Compounds in terms of Bandgap Distortion and Magnetic Effects

    Directory of Open Access Journals (Sweden)

    K. Boubaker

    2013-01-01

    Full Text Available Physical and chemical arguments for the recently discussed materials-related Lattice Compatibility Theory are presented. The discussed arguments are based on some differences of Mn ions incorporation kinetics inside some compounds. These differences have been evaluated and quantified in terms of alteration of bandgap edges, magnetic patterns, and Faraday effect.

  19. Altruism in terminal cancer patients and rapid tissue donation program: does the theory apply?

    Science.gov (United States)

    Quinn, Gwendolyn P; Murphy, Devin; Pratt, Christie; Muñoz-Antonia, Teresita; Guerra, Lucy; Schabath, Matthew B; Leon, Marino E; Haura, Eric

    2013-11-01

    Rapid tissue donation (RTD) is an advancing oncology research procedure for collecting tumors, metastases, and unaffected tissue 2-6 h after death. Researchers can better determine rates of progression, response to treatment, and polymorphic differences among patients. Cancer patients may inquire about posthumous body donation for research to offer a personal contribution to research; however, there are barriers to recruiting for an RTD program. Physicians must reassure the patient that their treatment options and quality of care will not be compromised due to participating in RTD. In this commentary we discuss how theories of altruism may explain cancer patients' desire to participate in an RTD program, the ethical concerns of health care professionals and patients and the use of altruism as a recruitment strategy. We offer recommendations for examining the cultural and ethical climate of the institution prior to initiating such a program such as examining the relationship of healthcare professionals and patients, identifying ethical concerns, and examining ways to promote acceptance and buy-in across professionals, patients, and families.

  20. Communication and general concern criterion prior to activation of the rapid response team: a grounded theory.

    Science.gov (United States)

    Martland, Jarrad; Chamberlain, Diane; Hutton, Alison; Smigielski, Michael

    2016-11-01

    Objective Patients commonly show signs and symptoms of deterioration for hours or days before cardiorespiratory arrest. Rapid response teams (RRT) were created to improve recognition and response to patient deterioration in these situations. Activation criteria include vital signs or 'general concern' by a clinician or family member. The general concern criterion for RRT activation accounts for nearly one-third of all RRT activity, and although it is well established that communication deficits between staff can contribute to poorer outcomes for patients, there is little evidence pertaining to communication and its effects on the general concern RRT activation. Thus, the aim of the present study was to develop a substantive grounded theory related to the communication process between clinicians that preceded the activation of an RRT when general concern criterion was used. Methods Qualitative grounded theory involved collection of three types of data details namely personal notes from participants in focus groups with white board notes from discussions and audio recordings of the focus groups sessions. Focus groups were conducted with participants exploring issues associated with clinician communication and how it related to the activation of an RRT using the general concern criterion. Results The three main phases of coding (i.e. open, axial and selective coding) analysis identified 322 separate open codes. The strongest theme contributed to a theory of ineffective communication and decreased psychological safety, namely that 'In the absence of effective communication there is a subsequent increase in anxiety, fear or concern that can be directly attributed to the activation of an RRT using the 'general concern' criterion'. The RRT filled cultural and process deficiencies in the compliance with an escalation protocol. Issues such as 'not for resuscitation documentation' and 'inability to establish communication with and between medical or nursing personnel' rated

  1. Theory of nonlinear, distortive phenomena in solids: Martensitic, crack, and multiscale structures-phenomenology and physics. Progress summary, 1991--1994

    Energy Technology Data Exchange (ETDEWEB)

    Sethna, J.P.; Krumhansl, J.A.

    1994-08-01

    We have identified tweed precursors to martensitic phase transformations as a spin glass phase due to composition variations, and used simulations and exact replica theory predictions to predict diffraction peaks and model phase diagrams, and provide real space data for comparison to transmission electron micrograph images. We have used symmetry principles to derive the crack growth laws for mixed-mode brittle fracture, explaining the results for two-dimensional fracture and deriving the growth laws in three dimensions. We have used recent advances in dynamical critical phenomena to study hysteresis in disordered systems, explaining the return-point-memory effect, predicting distributions for Barkhausen noise, and elucidating the transition from athermal to burst behavior in martensites. From a nonlinear lattice-dynamical model of a first-order transition using simulations, finite-size scaling, and transfer matrix methods, it is shown that heterophase transformation precursors cannot occur in a pure homogeneous system, thus emphasizing the role of disorder in real materials. Full integration of nonlinear Landau-Ginzburg continuum theory with experimental neutron-scattering data and first-principles calculations has been carried out to compute semi-quantitative values of the energy and thickness of twin boundaries in InTl and FePd martensites.

  2. Distortion dependent intersystem crossing

    DEFF Research Database (Denmark)

    Stephansen, Anne Boutrup; Sølling, Theis Ivan

    2017-01-01

    The competition between ultrafast intersystem crossing and internal conversion in benzene, toluene, and p-xylene is investigated with time-resolved photoelectron spectroscopy and quantum chemical calculations. By exciting to S2 out-of-plane symmetry breaking, distortions are activated at early...

  3. Time Distortions in Mind

    OpenAIRE

    Vatakis, A.; Allman, M.

    2015-01-01

    Time Distortions in Mind brings together current research on temporal processing in clinical populations to elucidate the interdependence between perturbations in timing and disturbances in the mind and brain. For the student, the scientist, and the stepping-stone for further research.

  4. Distortion in Perspective Projection

    Science.gov (United States)

    Kelso, Robert P., Sr.

    2008-01-01

    The paper presents a unique approach in associating perspective projection with the image beheld by the eye and demonstrates that all graphical and photographic perspective projections must contain distortion when compared to the image beheld by the eye. (Contains 8 figures.)

  5. Predictors of Child Molestation: Adult Attachment, Cognitive Distortions, and Empathy

    Science.gov (United States)

    Wood, Eric; Riggs, Shelley

    2008-01-01

    A conceptual model derived from attachment theory was tested by examining adult attachment style, cognitive distortions, and both general and victim empathy in a sample of 61 paroled child molesters and 51 community controls. Results of logistic multiple regression showed that attachment anxiety, cognitive distortions, high general empathy but low…

  6. Socioeconomic Inequality and Giftedness: Suppression and Distortion of High Ability

    Science.gov (United States)

    Ambrose, Don

    2013-01-01

    Severe socioeconomic inequality strongly suppresses and distorts the discovery of aspirations and the concomitant development of talents among the gifted. More comprehensive understanding of this suppression and distortion is available through a wide-ranging interdisciplinary search for research findings and theories that illuminate economic,…

  7. Modeling Kinetics of Distortion in Porous Bi-layered Structures

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye; Frandsen, Henrik Lund; Bjørk, Rasmus

    2013-01-01

    because of different sintering rates of the materials resulting in undesired distortions of the component. An analytical model based on the continuum theory of sintering has been developed to describe the kinetics of densification and distortion in the sintering processes. A new approach is used...... to extract the material parameters controlling shape distortion through optimizing the model to experimental data of free shrinkage strains. The significant influence of weight of the sample (gravity) on the kinetics of distortion is taken in to consideration. The modeling predictions indicate good agreement...

  8. Suicide and cognitive distortions

    Directory of Open Access Journals (Sweden)

    Éva Jekkel

    2004-05-01

    Full Text Available The process of preventing suicidal acts has been studied thoroughly. There are few studies concerning cognitive mechanisms preceding suicidal actions. Suicidal behaviour consists of complexity of biological, psychological, and social factors. The transition of these factors to suicide attempt appears to be determined by cognitive processes. In this article the authors give a short review of relevant literature. To answer the question whether there are specific suicidal cognitive distortions, the authors compared a group of suicidal patients with a matched control group. In the last section of the paper they analyse their data obtained by comparing the two groups using a set of tests.

  9. Implicit cognitive distortions and sexual offending.

    Science.gov (United States)

    Mihailides, Stephen; Devilly, Grant J; Ward, Tony

    2004-10-01

    This work develops and tests the semantic-motivation hypothesis of sexual offenders' implicit cognitions. This hypothesis posits that sexual offenders' cognitive distortions emerge at the interface between implicit motivation and cognition. The semantic-motivation hypothesis is used to guide the development of 3 implicit association tests (IATs). These IATs were used to test for the existence of 3 expected child sexual offender implicit cognitive distortions in child sexual offenders ("children as sexual beings," "uncontrollability of sexuality," and "sexual entitlement-bias"). Results showed that child sexual offenders had larger IAT effects than did mainstream offenders and male and female nonoffenders for the "children as sexual beings" and the "uncontrollability of sexuality" implicit theories. Child sexual offenders also had a larger IAT effect than male and female nonoffenders for the "sexual entitlement-bias" implicit theory. Implications for the semantic-motivation hypothesis are discussed.

  10. Distorted Fingerprint Verification System

    Directory of Open Access Journals (Sweden)

    Divya KARTHIKAESHWARAN

    2011-01-01

    Full Text Available Fingerprint verification is one of the most reliable personal identification methods. Fingerprint matching is affected by non-linear distortion introduced in fingerprint impression during the image acquisition process. This non-linear deformation changes both the position and orientation of minutiae. The proposed system operates in three stages: alignment based fingerprint matching, fuzzy clustering and classifier framework. First, an enhanced input fingerprint image has been aligned with the template fingerprint image and matching score is computed. To improve the performance of the system, a fuzzy clustering based on distance and density has been used to cluster the feature set obtained from the fingerprint matcher. Finally a classifier framework has been developed and found that cost sensitive classifier produces better results. The system has been evaluated on fingerprint database and the experimental result shows that system produces a verification rate of 96%. This system plays an important role in forensic and civilian applications.

  11. Cognitive Distortions and Suicide Attempts.

    Science.gov (United States)

    Jager-Hyman, Shari; Cunningham, Amy; Wenzel, Amy; Mattei, Stephanie; Brown, Gregory K; Beck, Aaron T

    2014-08-01

    Although theorists have posited that suicidal individuals are more likely than non-suicidal individuals to experience cognitive distortions, little empirical work has examined whether those who recently attempted suicide are more likely to engage in cognitive distortions than those who have not recently attempted suicide. In the present study, 111 participants who attempted suicide in the 30 days prior to participation and 57 psychiatric control participants completed measures of cognitive distortions, depression, and hopelessness. Findings support the hypothesis that individuals who recently attempted suicide are more likely than psychiatric controls to experience cognitive distortions, even when controlling for depression and hopelessness. Fortune telling was the only cognitive distortion uniquely associated with suicide attempt status. However, fortune telling was no longer significantly associated with suicide attempt status when controlling for hopelessness. Findings underscore the importance of directly targeting cognitive distortions when treating individuals at risk for suicide.

  12. Flat, distorted spiral structure in praseodymium and neodymium

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker

    1998-01-01

    A theory is given for the onset of distorted spiral order in Nd at T-2 below T-N. For Pr, the dominant quasielastic peak is due to induced sinusoidal magnetic ordering, which can be accounted for by mode-mode coupling theory. The second, broader peak is due to an induced, phase-locked transverse ...

  13. Rapid Asymmetric Inflation and Early Cosmology in Theories with Sub-Millimeter Dimensions

    CERN Document Server

    Arkani-Hamed, N; Kaloper, Nemanja; March-Russell, John David; Arkani-Hamed, Nima; Dimopoulos, Savas; Kaloper, Nemanja; March-Russell, John

    2000-01-01

    It was recently pointed out that the fundamental Planck mass could be close to the TeV scale with the observed weakness of gravity at long distances being due the existence of new sub-millimeter spatial dimensions. In this picture the standard model fields are localized to a $(3+1)$-dimensional wall or ``3-brane''. We show that in such theories there exist attractive models of inflation that occur while the size of the new dimensions are still small. We show that it is easy to produce the required number of efoldings, and further that the density perturbations $\\delta\\rho/\\rho$ as measured by COBE can be easily reproduced, both in overall magnitude and in their approximately scale-invariant spectrum. In the minimal approach, the inflaton field is just the moduli describing the size of the internal dimensions, the role of the inflationary potential being played by the stabilizing potential of the internal space. We show that under quite general conditions, the inflationary era is followed by an epoch of contra...

  14. Child molesters' cognitive distortions. Conceptualizations of the term.

    Science.gov (United States)

    Szumski, Filip; Zielona-Jenek, Monika

    2016-10-31

    The concept of cognitive distortion was created by A. T. Beck and it is one of the key-concepts of cognitive psychotherapy. In the 80s of the twentieth century, researchers began to use it in studies of sexual offending, but with reference to the social learning theory rather than to the theory of cognitive psychotherapy. Subsequent authors continued the use of this term in the determinants of child molestation and defined them as products emerging from specific implicit theory of the offender, the judgements resulting from his beliefs, values and actions, dysfunctional cognitive schemas, deviant cognitive practices undertaken in the interaction of internal and external components of perpetrator's cognitive system and his social practices. The primary theoretical background in the description of the concept of cognitive distortions of child molesters was the social cognition theory, but it was complemented with the assumptions of the theory of cognitive psychotherapy, extended theory of mind and discursive psychology perspective. Particular concepts describe the cognitive distortions relating them to different classes of cognitive phenomena: products, processes and structures, and the only thing they have in common is their incompatibility of their content to the social norms. Giving this concept a normative nature leads to internal contradictions within the conceptions that concern it. Moreover, using it to explain the various processes oversimplifies the picture of this phenomenon and leads to contradictions between theories. It is, therefore, necessary to consider replacing the term cognitive distortions with alternative and more precise concepts.

  15. Triangulation in Random Refractive Distortions.

    Science.gov (United States)

    Alterman, Marina; Schechner, Yoav Y; Swirski, Yohay

    2017-03-01

    Random refraction occurs in turbulence and through a wavy water-air interface. It creates distortion that changes in space, time and with viewpoint. Localizing objects in three dimensions (3D) despite this random distortion is important to some predators and also to submariners avoiding the salient use of periscopes. We take a multiview approach to this task. Refracted distortion statistics induce a probabilistic relation between any pixel location and a line of sight in space. Measurements of an object's random projection from multiple views and times lead to a likelihood function of the object's 3D location. The likelihood leads to estimates of the 3D location and its uncertainty. Furthermore, multiview images acquired simultaneously in a wide stereo baseline have uncorrelated distortions. This helps reduce the acquisition time needed for localization. The method is demonstrated in stereoscopic video sequences, both in a lab and a swimming pool.

  16. MATHEMATICAL SIMULATION OF WELDING DISTORTIONS IN THIN PLATES

    Directory of Open Access Journals (Sweden)

    Afshin Kheidari Monfared

    2011-01-01

    Full Text Available Welding is a crucial manufacturing process and widely used for manufacturing various products including ships, automobiles, trains and bridges. Welding distortions often occur in welded structures of thin plates due to relatively low stiffness and result in their warpage during assembly process and high manufacturing cost. Therefore, prediction and reduction of welding distortions are important in order to improve quality of welded structures. Welding distortion during the assembly process is caused not only by local shrinkage due to rapid heating and cooling. 3-D thermo-elastic-plastic finite element method (FEM has been used to simulate single-bead-on-plate welding with 1 mm thickness. Experiments have been carried out to prove the simulated results. Comparison of the experimental results and FEM simulation results has confirmed that the proposed method efficiently  predicts level of  welding distortions while making single-bead-on-plate welding with 1 mm thickness.

  17. Distortional eigenmodes and homogeneous solutions for semi-discretized thin-walled beams

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Andreassen, Michael Joachim

    2011-01-01

    The classical Vlasov theory for torsional analysis of thin-walled beams with open and closed cross-sections can be generalized by including distortional displacement fields. We show that the determination of adequate distortional displacement fields for generalized beam theory (GBT) can be found...... attention also for closed single or multi cell cross-sections. Further more the found eigenvalues have clear mechanical meaning, since they represent the attenuation of the distortional eigenmodes and may be used in the automatic meshing of approximate distortional beam elements. The magnitude...

  18. Distortion range of filter synthetic discriminant function binary phase-only filters

    Science.gov (United States)

    Jared, David A.

    1989-11-01

    This paper considers the performance of filter synthetic-discriminant-function binary-phase-only filters (fSDF-BPOFs) with images in the distortion range that were not members of the training set. This evaluation was performed to understand better the distortion range that can be effectively covered by fSDF-BPOFs. The peak correlation and peak clutter responses were measured over various distortion ranges for in-plane and out-of-plane rotations. The peak correlation initially decreased rapidly as the distortion range increased but decreased gradually as the distortion range became larger for the images used in this study. The distortion ranges that can be effectively covered by fSDF-BPOFs appear to be modest: 0-30 deg for in-plane rotation and 0-10 deg for out-of-plane rotation. The results indicate that a temporal multiplexing scheme will be required to cover a large distortion range when BPOFs are used.

  19. Resonance Raman study on distorted symmetry of porphyrin in ...

    Indian Academy of Sciences (India)

    2Cl2 (solvent) at different excitations such as 514.5, 488.0, 441.6 and 406.7 nm are recorded and analysed. The results of the theory of distortion-induced RR intensity is applied to the observed spectra to determine the excited electronic state ...

  20. Journal Afrika Statistika ISSN 0852-0305 Distortion risk measures ...

    African Journals Online (AJOL)

    Key words: Coherence; Dependence structure; Distortion function; Risk measure; Risk theory; insurance; Wang ... distribution function (df) F. The DRM of rv X, due to Wang [17], is defined as follows: πψ[X] := ..... Let X1 and X2 be two risks with joint df represented by the Clayton copula Cθ,θ> 0 and Pareto-distributed margins.

  1. Time distortion for expert and novice online game players.

    Science.gov (United States)

    Rau, Pei-Luen Patrick; Peng, Shu-Yun; Yang, Chin-Chow

    2006-08-01

    Online game addiction is a new mental disorder. This disorder is difficult to describe because of its comprehensive nature. Many online game players have problems controlling their playing time. They cannot stop playing a game that they enjoy. This research surveyed the past literature on "flow" and time disorder theory. A time distortion experiment was conducted. This research invited 64 children, teenagers, and young adults to investigate player skill and playing time effects on online game break-off. The playing experience and degree of time distortion were measured and analyzed. The results showed that both novice and expert online game players were subject to time distortion. The participants had difficulty breaking off from the game without intrusion by others in the real world. This research also suggests eight questions for self-evaluation for online game addiction.

  2. Motivational distortion of the 16PF by welfare recipients.

    Science.gov (United States)

    Merydith, S P; Humphreys, J K; Ebener, D J

    1997-10-01

    The effectiveness of the Sixteen Personality Factor (16PF) motivational distortion correction procedures was investigated with a sample of 212 welfare recipients who completed the 16PF while participating in a mandatory welfare-to-work program. A multiple regression analysis showed that the motivational distortion (MD) score was significantly related to most of the preselected Personality factors. The regression analysis also revealed that primary E (Dominance) was associated with MD, although the manual does not require MD adjustments for this factor. Based on comparisons of mean differences at the various MD correction levels, findings indicated general support for the MD correction procedures described in the manual; however, the magnitude of the correction procedures should be used cautiously as this may overcorrect for MD on some of the 16PF primaries. The relevance of the findings also are discussed in terms of evidence for Cattell's (1968, 1973, 1986) trait-view theory as it applies to response distortions.

  3. Detection and Rectification of Distorted Fingerprints.

    Science.gov (United States)

    Si, Xuanbin; Feng, Jianjiang; Zhou, Jie; Luo, Yuxuan

    2015-03-01

    Elastic distortion of fingerprints is one of the major causes for false non-match. While this problem affects all fingerprint recognition applications, it is especially dangerous in negative recognition applications, such as watchlist and deduplication applications. In such applications, malicious users may purposely distort their fingerprints to evade identification. In this paper, we proposed novel algorithms to detect and rectify skin distortion based on a single fingerprint image. Distortion detection is viewed as a two-class classification problem, for which the registered ridge orientation map and period map of a fingerprint are used as the feature vector and a SVM classifier is trained to perform the classification task. Distortion rectification (or equivalently distortion field estimation) is viewed as a regression problem, where the input is a distorted fingerprint and the output is the distortion field. To solve this problem, a database (called reference database) of various distorted reference fingerprints and corresponding distortion fields is built in the offline stage, and then in the online stage, the nearest neighbor of the input fingerprint is found in the reference database and the corresponding distortion field is used to transform the input fingerprint into a normal one. Promising results have been obtained on three databases containing many distorted fingerprints, namely FVC2004 DB1, Tsinghua Distorted Fingerprint database, and the NIST SD27 latent fingerprint database.

  4. Working memory and the memory distortion component of hindsight bias.

    Science.gov (United States)

    Calvillo, Dustin P

    2012-01-01

    One component of hindsight bias is memory distortion: Individuals' recollections of their predictions are biased towards known outcomes. The present study examined the role of working memory in the memory distortion component of hindsight bias. Participants answered almanac-like questions, completed a measure of working memory capacity, were provided with the correct answers, and attempted to recollect their original judgements in two conditions: with and without a concurrent working memory load. Participants' recalled judgements were more biased by feedback when they recalled these judgements with a concurrent memory load and working memory capacity was negatively correlated with memory distortion. These findings are consistent with reconstruction accounts of the memory distortion component of hindsight bias and, more generally, with dual process theories of cognition. These results also relate the memory distortion component of hindsight bias with other cognitive errors, such as source monitoring errors, the belief bias in syllogistic reasoning and anchoring effects. Implications for the separate components view of hindsight bias are discussed.

  5. Should sex-ratio distorting parasites abandon horizontal transmission?

    Science.gov (United States)

    2011-01-01

    Background Sex-ratio distorting parasites are of interest due to their effects upon host population dynamics and their potential to influence the evolution of host sex determination systems. In theory, the ability to distort host sex-ratios allows a parasite with efficient vertical (hereditary) transmission to dispense completely with horizontal (infectious) transmission. However, recent empirical studies indicate that some sex-ratio distorting parasites have retained the capability for horizontal transmission. Results Numerical simulations using biologically realistic parameters suggest that a feminising parasite is only likely to lose the capability for horizontal transmission if its host occurs at low density and/or has a male-biased primary sex ratio. It is also demonstrated that even a small amount of horizontal transmission can allow multiple feminising parasites to coexist within a single host population. Finally it is shown that, by boosting its host's rate of population growth, a feminising parasite can increase its own horizontal transmission and allow the invasion of other, more virulent parasites. Conclusions The prediction that sex-ratio distorting parasites are likely to retain a degree of horizontal transmission has important implications for the epidemiology and host-parasite interactions of these organisms. It may also explain the frequent co-occurrence of several sex-ratio distorting parasite species in nature. PMID:22188680

  6. Should sex-ratio distorting parasites abandon horizontal transmission?

    Directory of Open Access Journals (Sweden)

    Ironside Joseph E

    2011-12-01

    Full Text Available Abstract Background Sex-ratio distorting parasites are of interest due to their effects upon host population dynamics and their potential to influence the evolution of host sex determination systems. In theory, the ability to distort host sex-ratios allows a parasite with efficient vertical (hereditary transmission to dispense completely with horizontal (infectious transmission. However, recent empirical studies indicate that some sex-ratio distorting parasites have retained the capability for horizontal transmission. Results Numerical simulations using biologically realistic parameters suggest that a feminising parasite is only likely to lose the capability for horizontal transmission if its host occurs at low density and/or has a male-biased primary sex ratio. It is also demonstrated that even a small amount of horizontal transmission can allow multiple feminising parasites to coexist within a single host population. Finally it is shown that, by boosting its host's rate of population growth, a feminising parasite can increase its own horizontal transmission and allow the invasion of other, more virulent parasites. Conclusions The prediction that sex-ratio distorting parasites are likely to retain a degree of horizontal transmission has important implications for the epidemiology and host-parasite interactions of these organisms. It may also explain the frequent co-occurrence of several sex-ratio distorting parasite species in nature.

  7. A Precision Analysis of Camera Distortion Models.

    Science.gov (United States)

    Tang, Zhongwei; Grompone von Gioi, Rafael; Monasse, Pascal; Morel, Jean-Michel

    2017-06-01

    This paper addresses the question of identifying the right camera direct or inverse distortion model, permitting a high subpixel precision to fit to real camera distortion. Five classic camera distortion models are reviewed and their precision is compared for direct or inverse distortion. By definition, the three radially symmetric models can only model a distortion radially symmetric around some distortion center. They can be extended to deal with non-radially symmetric distortions by adding tangential distortion components, but still may be too simple for very accurate modeling of real cameras. The polynomial and the rational models instead miss a physical or optical interpretation, but can cope equally with radially and non-radially symmetric distortions. Indeed, they do not require the evaluation of a distortion center. When requiring high precisions, we found that the distortion modeling must also be evaluated primarily as a numerical problem. Indeed, all models except the polynomial involve a non-linear minimization, which increases the numerical risk. The estimation of a polynomial distortion model leads instead to a linear problem, which is secure and much faster. We concluded by extensive numerical experiments that, although high degree polynomials were required to reach a high precision of 1/100 pixels, such polynomials were easily estimated and produced a precise distortion modeling without overfitting. Our conclusion is validated by three independent experimental setups: the models were compared first on the lens distortion database of the Lensfun library by their distortion simulation and inversion power; second by fitting real camera distortions estimated by a non parametric algorithm; and finally by the absolute correction measurement provided by the photographs of tightly stretched strings, warranting a high straightness.

  8. Analysis of Brown camera distortion model

    Science.gov (United States)

    Nowakowski, Artur; Skarbek, Władysław

    2013-10-01

    Contemporary image acquisition devices introduce optical distortion into image. It results in pixel displacement and therefore needs to be compensated for many computer vision applications. The distortion is usually modeled by the Brown distortion model, which parameters can be included in camera calibration task. In this paper we describe original model, its dependencies and analyze orthogonality with regard to radius for its decentering distortion component. We also report experiments with camera calibration algorithm included in OpenCV library, especially a stability of distortion parameters estimation is evaluated.

  9. Understanding rapid evolution in predator‐prey interactions using the theory of fast‐slow dynamical systems.

    Science.gov (United States)

    Cortez, Michael H; Ellner, Stephen P

    2010-11-01

    The accumulation of evidence that ecologically important traits often evolve at the same time and rate as ecological dynamics (e.g., changes in species' abundances or spatial distributions) has outpaced theory describing the interplay between ecological and evolutionary processes with comparable timescales. The disparity between experiment and theory is partially due to the high dimensionality of models that include both evolutionary and ecological dynamics. Here we show how the theory of fast-slow dynamical systems can be used to reduce model dimension, and we use that body of theory to study a general predator-prey system exhibiting fast evolution in either the predator or the prey. Our approach yields graphical methods with predictive power about when new and unique dynamics (e.g., completely out-of-phase oscillations and cryptic dynamics) can arise in ecological systems exhibiting fast evolution. In addition, we derive analytical expressions for determining when such behavior arises and how evolution affects qualitative properties of the ecological dynamics. Finally, while the theory requires a separation of timescales between the ecological and evolutionary processes, our approach yields insight into systems where the rates of those processes are comparable and thus is a step toward creating a general ecoevolutionary theory.

  10. A distortional semi-discretized thin-walled beam element

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Jönsson, Jeppe

    2013-01-01

    Due to the increased consumption of thin-walled structural elements there has been increasing focus and need for more detailed calculations as well as development of new approaches. In this paper a thin-walled beam element including distortion of the cross section is formulated. The formulation...... is based on a generalized beam theory (GBT), in which the classic Vlasov beam theory for analysis of open and closed thin-walled cross sections is generalized by including distortional displacements. The beam element formulation utilizes a semi-discretization approach in which the cross section...... is discretized into wall elements and the analytical solutions of the related GBT beam equations are used as displacement functions in the axial direction. Thus the beam element contains the semi-analytical solutions. In three related papers the authors have recently presented the semi-discretization approach...

  11. Biological motion distorts size perception

    Science.gov (United States)

    Veto, Peter; Einhäuser, Wolfgang; Troje, Nikolaus F.

    2017-02-01

    Visual illusions explore the limits of sensory processing and provide an ideal testbed to study perception. Size illusions - stimuli whose size is consistently misperceived - do not only result from sensory cues, but can also be induced by cognitive factors, such as social status. Here we investigate, whether the ecological relevance of biological motion can also distort perceived size. We asked observers to judge the size of point-light walkers (PLWs), configurations of dots whose movements induce the perception of human movement, and visually matched control stimuli (inverted PLWs). We find that upright PLWs are consistently judged as larger than inverted PLWs, while static point-light figures do not elicit the same effect. We also show the phenomenon using an indirect paradigm: observers judged the relative size of a disc that followed an inverted PLW larger than a disc following an upright PLW. We interpret this as a contrast effect: The upright PLW is perceived larger and thus the subsequent disc is judged smaller. Together, these results demonstrate that ecologically relevant biological-motion stimuli are perceived larger than visually matched control stimuli. Our findings present a novel case of illusory size perception, where ecological importance leads to a distorted perception of size.

  12. Ubiquitous Log Odds: A Common Representation of Probability and Frequency Distortion in Perception, Action, and Cognition

    Science.gov (United States)

    Zhang, Hang; Maloney, Laurence T.

    2012-01-01

    In decision from experience, the source of probability information affects how probability is distorted in the decision task. Understanding how and why probability is distorted is a key issue in understanding the peculiar character of experience-based decision. We consider how probability information is used not just in decision-making but also in a wide variety of cognitive, perceptual, and motor tasks. Very similar patterns of distortion of probability/frequency information have been found in visual frequency estimation, frequency estimation based on memory, signal detection theory, and in the use of probability information in decision-making under risk and uncertainty. We show that distortion of probability in all cases is well captured as linear transformations of the log odds of frequency and/or probability, a model with a slope parameter, and an intercept parameter. We then consider how task and experience influence these two parameters and the resulting distortion of probability. We review how the probability distortions change in systematic ways with task and report three experiments on frequency distortion where the distortions change systematically in the same task. We found that the slope of frequency distortions decreases with the sample size, which is echoed by findings in decision from experience. We review previous models of the representation of uncertainty and find that none can account for the empirical findings. PMID:22294978

  13. Ubiquitous log odds: a common representation of probability and frequency distortion in perception, action and cognition

    Directory of Open Access Journals (Sweden)

    Hang eZhang

    2012-01-01

    Full Text Available In decision from experience, the source of probability information affects how probability is distorted in the decision task. Understanding how and why probability is distorted is a key issue in understanding the peculiar character of experience-based decision. We consider how probability information is used not just in decision making but also in a wide variety of cognitive, perceptual and motor tasks. Very similar patterns of distortion of probability/frequency information have been found in visual frequency estimation, frequency estimation based on memory, signal detection theory, and in the use of probability information in decision-making under risk and uncertainty. We show that distortion of probability in all cases is well captured as linear transformations of the log odds of frequency and/or probability, a model with a slope parameter and an intercept parameter. We then consider how task and experience influence these two parameters and the resulting distortion of probability. We review how the probability distortions change in systematic ways with task and report three experiments on frequency distortion where the distortions change systematically in the same task. We found that the slope of frequency distortions decreases with the sample size, which is echoed by findings in decision from experience. We review previous models of the representation of uncertainty and find that none can account for the empirical findings.

  14. Performance and Adaptive Surge-Preventing Acceleration Prediction of a Turboshaft Engine under Inlet Flow Distortion

    Directory of Open Access Journals (Sweden)

    Cao Dalu

    2017-01-01

    Full Text Available The intention of this paper is to research the inlet flow distortion influence on overall performance of turboshaft engine and put forward a method called Distortion Factor Item (DFI to improve the fuel supply plan for surge-preventing acceleration when turboshaft engine suddenly encounters inlet flow distortion. Based on the parallel compressor theory, steady-state and transition-state numerical simulation model of turboshaft engine with sub-compressor model were established for researching the influence of inlet flow distortion on turboshaft engine. This paper made a detailed analysis on the compressor operation from the aspects of performance and stability, and then analyzed the overall performance and dynamic response of the whole engine under inlet flow distortion. Improved fuel supply plan with DFI method was applied to control the acceleration process adaptively when encountering different inlet flow distortion. Several simulation examples about extreme natural environments were calculated to testify DFI method’s environmental applicability. The result shows that the inlet flow distortion reduces the air inflow and decreases the surge margin of compressor, and increase the engine exhaust loss. Encountering inlet flow distortion has many adverse influences such as sudden rotor acceleration, turbine inlet temperature rise and power output reduction. By using improved fuel supply plan with DFI, turboshaft engine above-idle acceleration can avoid surge effectively under inlet flow distortion with environmental applicability.

  15. Distorted Wave Calculations and Applications

    Science.gov (United States)

    Bhatia, A. K.; Fisher, Richard R. (Technical Monitor)

    2000-01-01

    Physical properties such as temperature and electron density of solar plasma and other astrophysical objects can be inferred from EUV and X-ray emission lines observed from space. These lines are emitted when the higher states of an ion are excited by electron impact and then decay by photon emission. Excitation cross sections are required for the spectroscopic analyses of the observations and various approximations have been used to calculate the scattering functions. One of them which has been widely used is a distorted wave approximation. This approximation, along with its applications to solar observations, is discussed. The Bowen fluorescence mechanism and optical depth effects are also discussed. It is concluded that such calculations are reliable for highly charged ions and for high electron temperatures.

  16. Dynamic Dazzle Distorts Speed Perception.

    Directory of Open Access Journals (Sweden)

    Joanna R Hall

    Full Text Available Static high contrast ('dazzle' patterns, such as zigzags, have been shown to reduce the perceived speed of an object. It has not escaped our notice that this effect has possible military applications and here we report a series of experiments on humans, designed to establish whether dynamic dazzle patterns can cause distortions of perceived speed sufficient to provide effective defence in the field, and the extent to which these effects are robust to a battery of manipulations. Dynamic stripe patterns moving in the same direction as the target are found to increase the perceived speed of that target, whilst dynamic stripes moving in the opposite direction to the target reduce the perceived speed. We establish the optimum position for such dazzle patches; confirm that reduced contrast and the addition of colour do not affect the performance of the dynamic dazzle, and finally, using the CO2 challenge, show that the effect is robust to stressful conditions.

  17. Mode distortion measurements on the Jefferson lab IR FEL

    CERN Document Server

    Benson, S V; Shinn, M

    2002-01-01

    We have previously reported on the analytical calculations of mirror distortion in a high-power FEL with a near-concentric cavity. This analysis allowed us to estimate the power level at which the FEL interaction would be affected, though no exact theory of FEL power vs. distortion exists at this point. Recently we have directly measured the mode size and beam quality as a function of power using a resonator with a center wavelength of 5 mu m. The resonator mirrors were calcium fluoride. This particular material exhibits a large amount of distortion for a given power but, due to the negative slope of refractive index vs. temperature, adds almost no optical phase distortion on the laser output. The mode in the cavity can thus be directly calculated from the measurements at the resonator output. The presence of angular jitter produced raw measurements inconsistent with cold cavity expectations. Removing the effects of the angular jitter, we derive results in agreement with cold cavity measurements. The result i...

  18. Static stereo vision depth distortions in teleoperation

    Science.gov (United States)

    Diner, D. B.; Von Sydow, M.

    1988-01-01

    A major problem in high-precision teleoperation is the high-resolution presentation of depth information. Stereo television has so far proved to be only a partial solution, due to an inherent trade-off among depth resolution, depth distortion and the alignment of the stereo image pair. Converged cameras can guarantee image alignment but suffer significant depth distortion when configured for high depth resolution. Moving the stereo camera rig to scan the work space further distorts depth. The 'dynamic' (camera-motion induced) depth distortion problem was solved by Diner and Von Sydow (1987), who have quantified the 'static' (camera-configuration induced) depth distortion. In this paper, a stereo image presentation technique which yields aligned images, high depth resolution and low depth distortion is demonstrated, thus solving the trade-off problem.

  19. Advanced Machining Toolpath for Low Distortion

    Science.gov (United States)

    2017-02-28

    completed a project funded by the Aviation Development Directorate (ADD) to minimize distortion in an aluminum fatigue coupon machining process. To achieve...of this project was delivery of an optimized NC toolpath that reflected the modeling efforts to minimize final part distortion. 2.0 TASK SUMMARY...W911W6-16-P-0044 6 NC Optimization The optimization strategy taken in this project focused on minimizing part distortion. To accomplish

  20. The theory and methodology of capturing and representing the design process and its application to the task of rapid redesign

    Science.gov (United States)

    Nii, Kendall M.

    The paradigm under which engineering design is being performed in the Aerospace industry is changing. There is an increased emphasis on a "faster, better, and cheaper" way of doing business. Designers are tasked with developing a better product, in a shorter time, with less money. Engineers are continually trying to improve their products, lower their costs, and reduce their schedules. So at first glance, it might seem difficult if not impossible to perform these three tasks simultaneously and attempt to achieve order of magnitude improvements in each area. Indeed it might well be impossible for an engineer using only traditional tools and techniques. However, there is a new tool, known as design capture, available to the designer. A design capture system, can aid the designer in a variety of ways. One specific use for a design capture system is to aid the designer in performing rapid redesign. This thesis presents a new methodology for a Design Capture System (DCS) which can aid the designer with performing rapid redesign. The Design Capture for Rapid Redesign (DCARRD) method facilitates rapid redesign in three ways: it allows the designer to assess the impact of changing an initial requirement, it allows the designer to assess the impact of changing a decision, and it enhances the ability of the designer to assess the impact of a completely new requirement. The DCARRD method was implemented into an html-based design capture system accessible through a Web browser. This implementation demonstrates the feasibility of the DCARRD method. The most important features of DCARRD are that it is focused an performing rapid redesign, it places the design decisions within the framework of the design process, it is simple to use and implement, and it has the ability to track subsystem baselines. The many complex issues surrounding testing of design tools in general, and DCARRD in particular, are discussed at length. There are a number of complex issues which must be addressed

  1. Specificity of cognitive distortions to antisocial behaviours.

    Science.gov (United States)

    Barriga, Alvaro Q; Hawkins, Mark A; Camelia, Carl R T

    2008-01-01

    Cognitive distortions have long been posited to facilitate antisocial behaviours, but the specificity of such distortions has rarely been studied. To replicate findings of specificity between particular cognitions and externalizing or internalizing behaviours; to test for specificity of relationship between particular cognitions and different types of externalizing behaviours. The participants were 239 male youths aged 10 to 19 years (mean (M) = 14.22, standard deviation (SD) = 1.64) from schools on the island of Curaçao. Their cognitive distortions and problem behaviours were investigated through self-report. Results In controlled analyses, self-serving cognitive distortions were associated with externalizing behaviours whereas self-debasing cognitive distortions were associated with internalizing behaviours. Within the externalizing domain, self-serving distortions with overt behavioural referents were linked to aggressive behaviour while self-serving distortions with covert behavioural referents were linked to delinquent behaviour. Within the aggression domain, distortions with opposition-defiance referents related to verbal aggression whereas distortions with physical aggression referents related to physically aggressive behaviour. The degree of cognitive-behavioural specificity documented by this study was remarkable. The observed pattern suggests that cognitive interventions designed for externalizing versus internalizing behaviours should differ in therapeutic approach.

  2. Harmonic Distortion in CMOS Current Mirrors

    DEFF Research Database (Denmark)

    Bruun, Erik

    1998-01-01

    One of the origins of harmonic distortion in CMOS current mirrors is the inevitable mismatch between the MOS transistors involved. In this paper we examine both single current mirrors and complementary class AB current mirrors and develop an analytical model for the mismatch induced harmonic...... distortion. This analytical model is verified through simulations and is used for a discussion of the impact of mismatch on harmonic distortion properties of CMOS current mirrors. It is found that distortion levels somewhat below 1% can be attained by carefully matching the mirror transistors but ultra low...

  3. Rapid calculation of protein chemical shifts using bond polarization theory and its application to protein structure refinement.

    Science.gov (United States)

    Jakovkin, Igor; Klipfel, Marco; Muhle-Goll, Claudia; Ulrich, Anne S; Luy, Burkhard; Sternberg, Ulrich

    2012-09-21

    Although difficult to analyze, NMR chemical shifts provide detailed information on protein structure. We have adapted the semi-empirical bond polarization theory (BPT) to protein chemical shift calculation and chemical shift driven protein structure refinement. A new parameterization for BPT amide nitrogen chemical shift calculation has been derived from MP2 ab initio calculations and successfully evaluated using crystalline tripeptides. We computed the chemical shifts of the small globular protein ubiquitin, demonstrating that BPT calculations can match the results obtained at the DFT level of theory at very low computational cost. In addition to the calculation of chemical shift tensors, BPT allows the calculation of chemical shift gradients and consequently chemical shift driven geometry optimizations. We applied chemical shift driven protein structure refinement to the conformational analysis of a set of Trypanosoma brucei (the causative agent of African sleeping sickness) tryparedoxin peroxidase Px III structures. We found that the interaction of Px III with its reaction partner Tpx seems to be governed by conformational selection rather than by induced fit.

  4. Distortional solutions for loaded semi-discretized thin-walled beams

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Jönsson, Jeppe

    2012-01-01

    For thin-walled beams, the classic theory for flexural and torsional analysis of open and closed cross-sections can be generalized by including distortional displacements. In a companion paper it is shown that using a novel semi-discretization process, it is possible to determine specific...... to built in ends, which are needed for future displacement formulation of an exact first-order distortional beam element....

  5. Redshift-space distortions around voids

    Science.gov (United States)

    Cai, Yan-Chuan; Taylor, Andy; Peacock, John A.; Padilla, Nelson

    2016-11-01

    We have derived estimators for the linear growth rate of density fluctuations using the cross-correlation function (CCF) of voids and haloes in redshift space. In linear theory, this CCF contains only monopole and quadrupole terms. At scales greater than the void radius, linear theory is a good match to voids traced out by haloes; small-scale random velocities are unimportant at these radii, only tending to cause small and often negligible elongation of the CCF near its origin. By extracting the monopole and quadrupole from the CCF, we measure the linear growth rate without prior knowledge of the void profile or velocity dispersion. We recover the linear growth parameter β to 9 per cent precision from an effective volume of 3( h-1Gpc)3 using voids with radius >25 h-1Mpc. Smaller voids are predominantly sub-voids, which may be more sensitive to the random velocity dispersion; they introduce noise and do not help to improve measurements. Adding velocity dispersion as a free parameter allows us to use information at radii as small as half of the void radius. The precision on β is reduced to 5 per cent. Voids show diverse shapes in redshift space, and can appear either elongated or flattened along the line of sight. This can be explained by the competing amplitudes of the local density contrast, plus the radial velocity profile and its gradient. The distortion pattern is therefore determined solely by the void profile and is different for void-in-cloud and void-in-void. This diversity of redshift-space void morphology complicates measurements of the Alcock-Paczynski effect using voids.

  6. Self-Compassion and Interpersonal Cognitive Distortions

    Science.gov (United States)

    Akin, Ahmet

    2010-01-01

    The purpose of this study is to examine the relationships between self-compassion and interpersonal cognitive distortions. Participants were 338 university students. In this study, the Self-compassion Scale and the Interpersonal Cognitive Distortions Scale were used. The relationships between self-compassion and interpersonal cognitive distortions…

  7. determination of determination of total harmonic distortion

    African Journals Online (AJOL)

    eobe

    Harmonic Distortion (THD) of the Distribution lines in the 33kV distri. Harmonic Distortion (THD) of the Distribution lines in the 33kV distribution network of Island Business District, bution network of Island Business District,. Eko Electricity Distribution Plc, taken. Eko Electricity Distribution Plc, taken as a case study using a set ...

  8. Graphite distortion ``C`` Reactor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wood, N.H.

    1962-02-08

    This report covers the efforts of the Laboratory in an investigation of the graphite distortion in the ``C`` reactor at Hanford. The particular aspects of the problem to be covered by the Laboratory were possible ``fixes`` to the control rod sticking problem caused by VSR channel distortion.

  9. Circuit Distortion Analysis Based on the Simplified Newton's Method

    Directory of Open Access Journals (Sweden)

    M. M. Gourary

    2011-01-01

    Full Text Available A new computational technique for distortion analysis of nonlinear circuits is presented. The new technique is applicable to the same class of circuits, namely, weakly nonlinear and time-varying circuits, as the periodic Volterra series. However, unlike the Volterra series, it does not require the computation of the second and third derivatives of device models. The new method is computationally efficient compared with a complete multitone nonlinear steady-state analysis such as harmonic balance. Moreover, the new technique naturally allows computing and characterizing the contributions of individual circuit components to the overall circuit distortion. This paper presents the theory of the new technique, a discussion of the numerical aspects, and numerical results.

  10. TPC track distortions III: fiat lux

    CERN Document Server

    Boyko, I; Dydak, F; Elagin, A; Gostkin, M; Guskov, A; Koreshev, V; Nefedov, Y; Nikolaev, K; Veenhof, R; Wotschack, J; Zhemchugov, A

    2005-01-01

    We present a comprehensive overview and final summary of all four types of static track distortions seen in the HARP TPC, in terms of physical origins, mathematical modelling, and correction algorithms. 'Static'™ distortions are defined as not depending on the event time within the 400 ms long accelerator spill. Calculated static distortions are compared with measurements from cosmic-muon tracks. We characterize track distortions by the r phi residuals of cluster positions with respect to the transverse projection of a helical trajectory constrained by hits in the RPC overlap regions. This method provides a fixed TPC-external reference system (by contrast to the co-moving coordinate system associated with a fit) which solely permits to identify individually, and measure quantitatively, the static TPC track distortions arising from (i) the inhomogeneity of the solenoidal magnetic field, (ii) the inhomogeneity of the electric field from the high-voltage mismatch between the inner and outer TPC field cages, (...

  11. Dynamic simulation for distortion image with turbulence atmospheric transmission effects

    Science.gov (United States)

    Du, Huijie; Fei, Jindong; Qing, Duzheng; Zhao, Hongming; Yu, Hong; Cheng, Chen

    2013-09-01

    The imaging through atmospheric turbulence is an inevitable problem encountered by infrared imaging sensors working in the turbulence atmospheric environment. Before light-rays enter the window of the imaging sensors, the atmospheric turbulence will randomly interfere with the transmission of the light waves came from the objects, causing the distribution of image intensity values on the focal plane to diffuse, the peak value to decrease, the image to get blurred, and the pixels to deviate, and making image identification very difficult. Owing to the fact of the long processing time and that the atmospheric turbulent flow field is unknown and hard to be described by mathematical models, dynamic simulation for distortion Image with turbulence atmospheric transmission effects is much more difficult and challenging in the world. This paper discusses the dynamic simulation for distortion Image of turbulence atmospheric transmission effect. First of all, with the data and the optical transmission model of the turbulence atmospheric, the ray-tracing method is applied to obtain the propagation path of optical ray which propagates through the high-speed turbulent flow field, and then to calculate the OPD from the reference wave to the reconverted wave front and obtain the point spread function (PSF). Secondly, infrared characteristics models of typical scene were established according to the theory of infrared physics and heat conduction, and then the dynamic infrared image was generated by OpenGL. The last step is to obtain the distortion Image with turbulence atmospheric transmission effects .With the data of atmospheric transmission computation, infrared simulation image of every frame was processed according to the theory of image processing and the real-time image simulation, and then the dynamic distortion simulation images with effects of blurring, jitter and shifting were obtained. Above-mentioned simulation method can provide the theoretical bases for recovering

  12. Sonographic ally Detected Architectural Distortion: Clinical Significance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Shin Kee; Seo, Bo Kyoung; Yi, Ann; Cha, Sang Hoon; Kim, Baek Hyun; Cho, Kyu Ran; Kim, Young Sik; Son, Gil Soo; Kim, Young Soo; Kim, Hee Young [Korea University Ansan Hospital, Ansan (Korea, Republic of)

    2008-12-15

    Architectural distortion is a suspicious abnormality for the diagnosis of breast cancer. The aim of this study was to investigate the clinical significance of sonographic ally detected architectural distortion. From January 2006 to June 2008, 20 patients were identified who had sonographic ally detected architectural distortions without a history of trauma or surgery and abnormal mammographic findings related to an architectural distortion. All of the lesions were pathologically verified. We evaluated the clinical and pathological findings and then assessed the clinical significance of the sonographic ally detected architectural distortions. Based on the clinical findings, one (5%) of the 20 patients had a palpable lump and the remaining 19 patients had no symptoms. No patient had a family history of breast cancer. Based on the pathological findings, three (15%) patients had malignancies. The malignant lesions included invasive ductal carcinomas (n = 2) and ductal carcinoma in situ (n = 1). Four (20%) patients had high-risk lesions: atypical ductal hyperplasia (n = 3) and lobular carcinoma in situ (n = 1). The remaining 13 (65%) patients had benign lesions, however, seven (35%) out of 13 patients had mild-risk lesions (three intraductal papillomas, three moderate or florid epithelial hyperplasia and one sclerosing adenosis). Of the sonographic ally detected architectural distortions, 35% were breast cancers or high-risk lesions and 35% were mild-risk lesions. Thus, a biopsy might be needed for an architectural distortion without an associated mass as depicted on breast ultrasound, even though the mammographic findings are normal

  13. Experimental and finite element analysis of residual stress and distortion in GTA welding of modified 9Cr-1Mo steel

    Energy Technology Data Exchange (ETDEWEB)

    Zubairuddin, M.; Chaudhari, V. [Institute for Plasma Research, Gandhinagar (India); Albert, S. K.; Mahadevan, S.; Vasudevan, M. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Suri, V. K. [Bhabha Atomic Research Centre, Mumbai (India)

    2014-12-15

    In this paper, investigation of residual stress and distortion induced in 3 mm thick Modified 9Cr-1Mo steel plates during GTA welding is carried out. SYSWELD software is used for the thermo-mechanical analysis. A 3D meshed model is created for the simulation and double ellipsoidal heat source distribution is used for the thermal analysis. Thermal cycles predicted near the fusion zone are compared with experimentally measured thermal cycles using thermocouples. Predicted residual stress profile across the fusion zone is compared with the measured profile using X-ray diffraction method. There is a good agreement between measured and predicted thermal cycles and residual stress profile. Distortion of the weld joint is measured using vertical electronic height gauge. Finite element analysis of distortion of the weld joint is carried out by applying both large and small distortion theories. Comparison of experimental and numerical results showed better accuracy if large distortion theory is applied.

  14. Distorted representation in visual tourism research

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    2016-01-01

    . On this background, this paper develops the notion ‘distorted representation’ to illustrate that blurred and obscure photos can in fact be intelligible and sensible in understanding tourism. Through an exploration of the overwhelmed and unintended practices of visual fieldwork, distorted representation illustrates...... how photographic materialities, performativities and sensations contribute to new tourism knowledges. While highlighting the potential of distorted representation, the paper posits a cautionary note in regards to the influential role of academic journals in determining the qualities of visual data...

  15. Testing for Distortions in Performance Measures

    DEFF Research Database (Denmark)

    Sloof, Randolph; Van Praag, Mirjam

    2015-01-01

    Distorted performance measures in compensation contracts elicit suboptimal behavioral responses that may even prove to be dysfunctional (gaming). This paper applies the empirical test developed by Courty and Marschke (Review of Economics and Statistics, 90, 428-441) to detect whether the widely...... used class of residual income-based performance measures-such as economic value added (EVA)-is distorted, leading to unintended agent behavior. The paper uses a difference-in-differences approach to account for changes in economic circumstances and the self-selection of firms using EVA. Our findings...... indicate that EVA is a distorted performance measure that elicits the gaming response....

  16. Testing for Distortions in Performance Measures

    DEFF Research Database (Denmark)

    Sloof, Randolph; Van Praag, Mirjam

    Distorted performance measures in compensation contracts elicit suboptimal behavioral responses that may even prove to be dysfunctional (gaming). This paper applies the empirical test developed by Courty and Marschke (2008) to detect whether the widely used class of Residual Income based...... performance measures —such as Economic Value Added (EVA)— is distorted, leading to unintended agent behavior. The paper uses a difference-in-differences approach to account for changes in economic circumstances and the self-selection of firms using EVA. Our findings indicate that EVA is a distorted...... performance measure that elicits the gaming response....

  17. Experiments on rapidly-sheared wall turbulence

    Science.gov (United States)

    Diwan, Sourabh; Morrison, Jonathan

    2013-11-01

    The use of linear theories in wall turbulence dates back to Townsend (1976, Cambridge University Press) who extensively used Rapid Distortion Theory (RDT) for understanding the structure of near-wall turbulence. Various other linear tools have been used in more recent investigations. The present study is an attempt to further explore this aspect and is in part motivated by the recent numerical work of Sharma et al. (Phys. Fluids 23, 2011) that highlighted the possible role of linear mechanisms in wall turbulence. Our experimental arrangement involves passing a grid-generated turbulent flow over a flat plate mounted downstream of the grid in a wind tunnel. The grid turbulence is subjected to large rates of shear strain by the wall layer close to the leading edge of the plate and as a result, over a certain region in its vicinity, the approximations of the RDT can be expected to be approximately satisfied. We present detailed single-point and planar velocity measurements, and pressure measurements using surface-mounted pressure transducers, the aim being to establish a turbulent wall layer in which linear processes are dominant. Such a flow can be used to evaluate the ideas relating to linear theories of Townsend and Landahl, among others. We also present the structural changes that take place as the rapidly-sheared wall layer evolves towards a more conventional boundary layer further downstream. We acknowledge financial support from EPSRC under Grant No. EP/I037938.

  18. Assessing the sensitivity of information distortion to four potential influences in studies of risky choice

    Directory of Open Access Journals (Sweden)

    Seth A. Miller

    2013-11-01

    Full Text Available The emergence of a leading alternative during the course of a decision is known to bias the evaluation of new information in a manner that favors that alternative. We report 3 studies that address the sensitivity of predecisional information distortion and its effects in hypothetical risky decisions with regard to 4 potential influences: choice domain, repeated choice, memory requirements, and intermediate progress questions. In Experiment 1 (N = 515, the magnitude of information distortion was similar in 5 choice domains (varied between participants involving monetary gambles, song downloads, frequent-flyer miles, political decisions, or medical decisions. Information distortion mediated the relationship between our manipulation of initial preferences and participants' final choices, with the magnitude of the indirect effect being roughly similar across domains. These results replicate and extend previous findings. Additionally, distortion decreased significantly over 4 similar decision problems (within participants, but remained significant in the fourth problem. In Experiment 2 (N = 214, information distortion increased significantly when previously viewed information remained available, apparently because reiterating that information strengthened emerging preferences. In Experiment 3 (N = 223, the removal of intermediate progress questions that measure information distortion and emerging preferences did not significantly affect final choices, again replicating previous results. We conclude that predecisional information distortion is a relatively stable and robust phenomenon that deserves a prominent role in descriptive theories of choice.

  19. Cognitive distortions in an acutely traumatized sample: an investigation of predictive power and neural correlates.

    Science.gov (United States)

    Daniels, J K; Hegadoren, K; Coupland, N J; Rowe, B H; Neufeld, R W J; Lanius, R A

    2011-10-01

    Current theories of post-traumatic stress disorder (PTSD) place considerable emphasis on the role cognitive distortions such as self-blame, hopelessness or preoccupation with danger play in the etiology and maintenance of the disorder. Previous studies have shown that cognitive distortions in the early aftermath of traumatic events can predict future PTSD severity but, to date, no studies have investigated the neural correlates of this association. We conducted a prospective study with 106 acutely traumatized subjects, assessing symptom severity at three time points within the first 3 months post-trauma. A subsample of 20 subjects additionally underwent a functional 4-T magnetic resonance imaging (MRI) scan at 2 to 4 months post-trauma. Cognitive distortions proved to be a significant predictor of concurrent symptom severity in addition to diagnostic status, but did not predict future symptom severity or diagnostic status over and above the initial symptom severity. Cognitive distortions were correlated with blood oxygen level-dependent (BOLD) signal strength in brain regions previously implicated in visual processing, imagery and autobiographic memory recall. Intrusion characteristics accounted for most of these correlations. This investigation revealed significant predictive value of cognitive distortions concerning concurrent PTSD severity and also established a significant relationship between cognitive distortions and neural activations during trauma recall in an acutely traumatized sample. These data indicate a direct link between the extent of cognitive distortions and the intrusive nature of trauma memories.

  20. Essays on Productivity and Distortions

    OpenAIRE

    Li, Kun

    2016-01-01

    Ma dissertation utilise des outils théoriques et des méthodes empiriques pour aborder des questions de fond dans l'intersection de la macroéconomie et de l'organisation industrielle. En particulier, mes recherches mettent l'accent sur la compréhension des forces sous-jacentes qui déterminent l'efficacité et les distorsions. Tout d'abord, je demande que, dans quelle mesure et par quel canal la privatisation a contribué à la croissance rapide du PIB et de la PTF dans le secteur manufacturier ch...

  1. Expertise and processing distorted structure in chess

    National Research Council Canada - National Science Library

    Bartlett, James C; Boggan, Amy L; Krawczyk, Daniel C

    2013-01-01

    ...). Focusing on the domain of chess, we present new fMRI evidence that when experts view such distorted/within-domain stimuli, they engage an active search for structure-a kind of exploratory chunking...

  2. Harmonic distortion in microwave photonic filters.

    Science.gov (United States)

    Rius, Manuel; Mora, José; Bolea, Mario; Capmany, José

    2012-04-09

    We present a theoretical and experimental analysis of nonlinear microwave photonic filters. Far from the conventional condition of low modulation index commonly used to neglect high-order terms, we have analyzed the harmonic distortion involved in microwave photonic structures with periodic and non-periodic frequency responses. We show that it is possible to design microwave photonic filters with reduced harmonic distortion and high linearity even under large signal operation.

  3. Satellite Video Stabilization with Geometric Distortion

    OpenAIRE

    Wang, Xia; Zhang, Guo; Shen, Xin; Li, Beibei; Jiang, Yonghua

    2016-01-01

    There is an exterior orientation difference in each satellite video frame, and the corresponding points have different image locations in adjacent frames images which has geometric distortion. So the projection model, affine model and other classical image stabilization registration model cannot accurately describe the relationship between adjacent frames. This paper proposes a new satellite video image stabilization method with geometric distortion to solve the problem, based on the simulate...

  4. Social perception deficits, cognitive distortions, and empathy deficits in sex offenders: a brief review.

    Science.gov (United States)

    Blake, Emily; Gannon, Theresa

    2008-01-01

    This literature review examines the differences between sex offenders and nonoffenders with regard to social perception skills, cognitive distortions, and empathy skills in order to investigate sex offenders' cognition. The literature on cognitive distortions is discussed, with reference to the confusion surrounding its definition, and the debate between cognitive distortions as offense-supportive beliefs or justifications is examined. In terms of social perception, particular reference is made to sex offenders' misinterpretations of women's social cues and the source of this deficit. The authors discuss possibilities for this deficit, including offense-supportive beliefs that are driven by underlying implicit theories or schemata held by offenders. The concept of empathy and its relation to both social perception skills and cognitive distortions is discussed, and the integration of these factors is represented in a new model.

  5. Ultrasonographic Findings of Mammographic Architectural Distortion

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jeong Hyun; Kang, Bong Joo; Cha, Eun Suk; Hwangbo, Seol; Kim, Hyeon Sook; Park, Chang Suk; Kim, Sung Hun; Choi, Jae Jeong; Chung, Yong An [Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    To review the sonographic findings of various diseases showing architectural distortion depicted under mammography. We collected and reviewed architectural distortions observed under mammography at our health institution between 1 March 2004, and 28 February 2007. We collected 23 cases of sonographically-detected mammographic architectural distortions that confirmed lesions after surgical resection. The sonographic findings of mammographic architectural distortion were analyzed by use of the BI-RADS lexicon for shape, margin, lesion boundary, echo pattern, posterior acoustic feature and orientation. There were variable diseases that showed architectural distortion depicted under mammography. Fibrocystic disease was the most common presentation (n = 6), followed by adenosis (n = 2), stromal fibrosis (n = 2), radial scar (n = 3), usual ductal hyperplasia (n = 1), atypical ductal hyperplasia (n = 1) and mild fibrosis with microcalcification (n = 1). Malignant lesions such as ductal carcinoma in situ (DCIS) (n = 2), lobular carcinoma in situ (LCIS) (n = 2), invasive ductal carcinoma (n = 2) and invasive lobular carcinoma (n = 1) were observed. As observed by sonography, shape was divided as irregular (n = 22) and round (n = 1). Margin was divided as circumscribed (n = 1), indistinct (n = 7), angular (n = 1), microlobulated (n = 1) and sipculated (n = 13). Lesion boundary was divided as abrupt interface (n = 11) and echogenic halo (n = 12). Echo pattern was divided as hypoechoic (n = 20), anechoic (n = 1), hyperechoic (n = 1) and isoechoic (n = 1). Posterior acoustic feature was divided as posterior acoustic feature (n = 7), posterior acoustic shadow (n = 15) and complex posterior acoustic feature (n = 1). Orientation was divided as parallel (n = 12) and not parallel (n = 11). There were no differential sonographic findings between benign and malignant lesions. This study presented various sonographic findings of mammographic architectural distortion and that it is

  6. Magnetotelluric distortions directly observed with lightning data

    Science.gov (United States)

    Hennessy, Lachlan; Macnae, James

    2017-08-01

    Galvanic distortions complicate magnetotelluric (MT) soundings. In this research, we use lightning network data to identify specific sferics in MT measurements and analyse these events on the basis of the lightning source location. Without source information, identification and removal of galvanic distortion is a fundamentally ill-posed problem, unless data are statistically decomposed into determinable and indeterminable parts. We use realistic assumptions of the earth-ionosphere waveguide propagation velocity to accurately predict the time of arrival, azimuth and amplitude for every significant sferic in our time-series data. For each sferic with large amplitude, we calculate the rotation of the electric field from the measured to the predicted arrival azimuth. This rotation of the electric field is a primary parameter of distortion. Our results demonstrate that a rudimentary model for near-surface galvanic distortion consistently fits observed electric field rotations. When local features rotate regional electric fields, then counter-rotating data to predicted arrival azimuths should correct the directional dependence of static shift. Although we used amplitude thresholds to simplify statistical processing, future developments should incorporate both signal-to-noise improvements and multisite decompositions. Lower amplitude signal may also be useful after the appropriate signal processing for noise reduction. We anticipate our approach will be useful for further work on MT distortion.

  7. Rapid QM/MM approach for biomolecular systems under periodic boundary conditions: Combination of the density-functional tight-binding theory and particle mesh Ewald method.

    Science.gov (United States)

    Nishizawa, Hiroaki; Okumura, Hisashi

    2016-12-05

    A quantum mechanical/molecular mechanical (QM/MM) approach based on the density-functional tight-binding (DFTB) theory is a useful tool for analyzing chemical reaction systems in detail. In this study, an efficient QM/MM method is developed by the combination of the DFTB/MM and particle mesh Ewald (PME) methods. Because the Fock matrix, which is required in the DFTB calculation, is analytically obtained by the PME method, the Coulomb energy is accurately and rapidly computed. For assessing the performance of this method, DFTB/MM calculations and molecular dynamics simulation are conducted for a system consisting of two amyloid-β(1-16) peptides and a zinc ion in explicit water under periodic boundary conditions. As compared with that of the conventional Ewald summation method, the computational cost of the Coulomb energy by utilizing the present approach is drastically reduced, i.e., 166.5 times faster. Furthermore, the deviation of the electronic energy is less than 10-6 Eh. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Expertise and processing distorted structure in chess.

    Science.gov (United States)

    Bartlett, James C; Boggan, Amy L; Krawczyk, Daniel C

    2013-01-01

    A classic finding in research on human expertise and knowledge is that of enhanced memory for stimuli in a domain of expertise as compared to either stimuli outside that domain, or within-domain stimuli that have been degraded or distorted in some way. However, we do not understand how experts process degradation or distortion of stimuli within the expert domain (e.g., a face with the eyes, nose, and mouth in the wrong positions, or a chessboard with pieces placed randomly). Focusing on the domain of chess, we present new fMRI evidence that when experts view such distorted/within-domain stimuli, they engage an active search for structure-a kind of exploratory chunking-that involves a component of a prefrontal-parietal network linked to consciousness, attention and working memory.

  9. Expertise and Processing Distorted Structure in Chess

    Directory of Open Access Journals (Sweden)

    James eBartlett

    2013-12-01

    Full Text Available A classic finding in research on human expertise and knowledge is that of enhanced memory for stimuli in a domain of expertise as compared to either stimuli outside that domain, or within-domain stimuli that have been or degraded or distorted in some way. However, we do not understand how the expert brain processes within-domain stimuli that have been distorted enough to be perceived as impossible or wrong, and yet still are perceived as within the domain (e.g., a face with the eyes, nose and mouth in the wrong positions, or a chessboard with pieces placed randomly on the board. Focusing on the domain of chess, we present new fMRI evidence that when experts view such distorted/within-domain stimuli, they engage an active search for structure – a kind of exploratory chunking – that involves a component of a prefrontal-parietal network linked to consciousness, attention and working memory.

  10. Distortion Analysis Toolkit—A Software Tool for Easy Analysis of Nonlinear Audio Systems

    Directory of Open Access Journals (Sweden)

    Jyri Pakarinen

    2010-01-01

    Full Text Available Several audio effects devices deliberately add nonlinear distortion to the processed signal in order to create a desired sound. When creating virtual analog models of nonlinearly distorting devices, it would be very useful to carefully analyze the type of distortion, so that the model could be made as realistic as possible. While traditional system analysis tools such as the frequency response give detailed information on the operation of linear and time-invariant systems, they are less useful for analyzing nonlinear devices. Furthermore, although there do exist separate algorithms for nonlinear distortion analysis, there is currently no unified, easy-to-use tool for rapid analysis of distorting audio systems. This paper offers a remedy by introducing a new software tool for easy analysis of distorting effects. A comparison between a well-known guitar tube amplifier and two commercial software simulations is presented as a case study. This freely available software is written in Matlab language, but the analysis tool can also run as a standalone program, so the user does not need to have Matlab installed in order to perform the analysis.

  11. Strong-field tidal distortions of rotating black holes. III. Embeddings in hyperbolic three-space

    Science.gov (United States)

    Penna, Robert F.; Hughes, Scott A.; O'Sullivan, Stephen

    2017-09-01

    In previous work, we developed tools for quantifying the tidal distortion of a black hole's event horizon due to an orbiting companion. These tools use techniques which require large mass ratios (companion mass μ much smaller than black hole mass M ), but can be used for arbitrary bound orbits and for any black hole spin. We also showed how to visualize these distorted black holes by embedding their horizons in a global Euclidean three-space, E3. Such visualizations illustrate interesting and important information about horizon dynamics. Unfortunately, we could not visualize black holes with spin parameter a*>√{3 }/2 ≈0.866 : such holes cannot be globally embedded into E3. In this paper, we overcome this difficulty by showing how to embed the horizons of tidally distorted Kerr black holes in a hyperbolic three-space, H3. We use black hole perturbation theory to compute the Gaussian curvatures of tidally distorted event horizons, from which we build a two-dimensional metric of their distorted horizons. We develop a numerical method for embedding the tidally distorted horizons in H3. As an application, we give a sequence of embeddings into H3 of a tidally interacting black hole with spin a*=0.9999 . A small-amplitude, high-frequency oscillation seen in previous work shows up particularly clearly in these embeddings.

  12. Distortion-free delta-sigma beamforming.

    Science.gov (United States)

    Nilsen, Carl-Inge Colombo; Holm, Sverre

    2008-08-01

    We have analyzed a compact, digital delay- and-sum beamformer using 1-bit delta-sigma A/D converters, where dynamic delays are applied directly to the delta-sigma modulated bitstream. It has previously been shown that the introduction of this time-variant operation into the time-invariant delta-sigma demodulator distorts the output signal, and several methods for minimizing this effect have been suggested. We have described the effect using standard system terminology. Based on this description, a new method for removing the distortion without any significant increase in system complexity is introduced. Its advantages, performance-wise, are supported by theoretical assessments and simulations.

  13. Multi-scale modeling of shape distortions during sintering of bi-layers

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye; Bjørk, Rasmus; Olevsky, Eugene

    2014-01-01

    Models for deformational behaviors of porous bodies during sintering often rely on limited number of internal variables as they are formulated based on simplified or ideal microstructures. Considering realistic microstructures can improve the predictive capabilities of the already established...... theories like the continuum theory of sintering. A new multi-scale numerical approach for modeling of shape distortions during sintering of macroscopically inhomogeneous structures combined with a microstructure model is developed. The microstructures of the porous body are described by unit cells based...

  14. Synchronization of cubic distortion spontaneous otoacoustic emissions

    NARCIS (Netherlands)

    van Dijk, P; Wit, HP

    A spontaneous otoacoustic emission spectrum may contain equally spaced emission peaks. Then, two peaks, at frequencies, f(1) and f(2), respectively, apparently generate a distortion product at f(d)=2f(1)-f(2) [or 2f(2)-f(1)]. For the three emission peaks of nine of such triplets tin six emission

  15. Audible Aliasing Distortion in Digital Audio Synthesis

    Directory of Open Access Journals (Sweden)

    J. Schimmel

    2012-04-01

    Full Text Available This paper deals with aliasing distortion in digital audio signal synthesis of classic periodic waveforms with infinite Fourier series, for electronic musical instruments. When these waveforms are generated in the digital domain then the aliasing appears due to its unlimited bandwidth. There are several techniques for the synthesis of these signals that have been designed to avoid or reduce the aliasing distortion. However, these techniques have high computing demands. One can say that today's computers have enough computing power to use these methods. However, we have to realize that today’s computer-aided music production requires tens of multi-timbre voices generated simultaneously by software synthesizers and the most of the computing power must be reserved for hard-disc recording subsystem and real-time audio processing of many audio channels with a lot of audio effects. Trivially generated classic analog synthesizer waveforms are therefore still effective for sound synthesis. We cannot avoid the aliasing distortion but spectral components produced by the aliasing can be masked with harmonic components and thus made inaudible if sufficient oversampling ratio is used. This paper deals with the assessment of audible aliasing distortion with the help of a psychoacoustic model of simultaneous masking and compares the computing demands of trivial generation using oversampling with those of other methods.

  16. Modelling the Perceptual Components of Loudspeaker Distortion

    DEFF Research Database (Denmark)

    Olsen, Sune L.; Agerkvist, Finn T.; MacDonald, Ewen

    2016-01-01

    While non-linear distortion in loudspeakers decreases audio quality, the perceptual consequences can vary substantially. This paper investigates the metric Rnonlin [1] which was developed to predict subjective measurements of sound quality in nonlinear systems. The generalisability of the metric...

  17. Distortion invariant pattern recognition with phase filters

    Science.gov (United States)

    Rosen, Joseph; Shamir, Joseph

    1987-01-01

    A recently developed approach for pattern recognition using spatial filters with reduced tolerance requirements is employed for the generation of filters containing mainly phase information. As anticipated, the recognition levels were decreased, but they remain adequate for unambiguous identification together with appreciable amounts of distortion immunity. Furthermore, the information content of the filters is compatible with low devices like spatial light modulators.

  18. [Body image and body image distortion].

    Science.gov (United States)

    Ábrahám, Ildikó; Jambrik, Máté; John, Balázs; Németh, Adrienn Réka; Franczia, Nóra; Csenki, Laura

    2017-05-01

    The aim of this literature review is to integrate the results of various studies regarding body image and body image distortion into a unified framework. The concept of body image is complex and can be interpreted from multiple points of view. The first part of the study touches upon different age characteristics, attentional focus on the body, the early and important role of the body in identity formation, specific features in adolescence, gender differences, and the often-observed stability of body image (distortion), which may be present as a (trait) marker throughout the lifespan. The second part focuses on the organization of body image. The results of different studies on cognitive information processing are reviewed, the question of perceptual accuracy is addressed and the concepts of embodiment are examined. The third topic is body image distortion. First, the concept is contextualized along different continua, then discussed in a clinical sense along with the complexity of diagnostic methods, as well as the state and trait aspects of body image distortion. Orv Hetil. 2017; 158(19): 723-730.

  19. Digital compensation of nonlinear distortion in loudspeakers

    NARCIS (Netherlands)

    de Vries, Ruurd; Berkhoff, Arthur P.; Slump, Cornelis H.; Herrmann, O.E.

    The authors present a method to compensate for loudspeaker distortion in real time by nonlinear digital signal processing implemented on a digital signal processor (i.e., the TMS320C30 DSP). Based on the literature, an electrical equivalent circuit of an electrodynamic loudspeaker is developed,

  20. Molecular distortion and charge transfer effects in ZnPc/Cu(111)

    KAUST Repository

    Amin, B.

    2013-04-23

    The adsorption geometry and electronic properties of a zinc-phthalocyanine molecule on a Cu(111) substrate are studied by density functional theory. In agreement with experiment, we find remarkable distortions of the molecule, mainly as the central Zn atom tends towards the substrate to minimize the Zn-Cu distance. As a consequence, the Zn-N chemical bonding and energy levels of the molecule are significantly modified. However, charge transfer induces metallic states on the molecule and therefore is more important for the ZnPc/Cu(111) system than the structural distortions.

  1. Interliminal Design: Understanding cognitive heuristics to mitigate design distortion

    Directory of Open Access Journals (Sweden)

    Andrew McCollough

    2014-12-01

    Full Text Available Cognitive heuristics are mental shortcuts adapted over time to enable rapid interpretation of our complex environment. They are intrinsic to human cognition and resist modification. Heuristics applied outside the context to which they are best suited are termed cognitive bias, and are the cause of systematic errors in judgment and reasoning. As both a cognitive and intuitive discipline, design by individuals is vulnerable to context-inappropriate heuristic usage. Designing in groups can act positively to counterbalance these tendencies, but is subject to heuristic misuse and biases particular to social environments. Mismatch between desired and actual outcomes– termed here, design distortion – occurs when such usage goes unnoticed and unaddressed, and can affect multiple dimensions of a system. We propose a methodology, interliminal design, emerging from the Program in Collaborative Design at Pacific Northwest College of Art, to specifically address the influence of cognitive heuristics in design. This adaptive approach involves reflective, dialogic, inquiry-driven practices intended to increase awareness of heuristic usage, and identify aspects of the design process vulnerable to misuse on both individual and group levels. By facilitating the detection and mitigation of potentially costly errors in judgment and decision-making that create distortion, such metacognitive techniques can meaningfully improve design.

  2. Multipole analysis of redshift-space distortions around cosmic voids

    Science.gov (United States)

    Hamaus, Nico; Cousinou, Marie-Claude; Pisani, Alice; Aubert, Marie; Escoffier, Stéphanie; Weller, Jochen

    2017-07-01

    We perform a comprehensive redshift-space distortion analysis based on cosmic voids in the large-scale distribution of galaxies observed with the Sloan Digital Sky Survey. To this end, we measure multipoles of the void-galaxy cross-correlation function and compare them with standard model predictions in cosmology. Merely considering linear-order theory allows us to accurately describe the data on the entire available range of scales and to probe void-centric distances down to about 2 h-1Mpc. Common systematics, such as the Fingers-of-God effect, scale-dependent galaxy bias, and nonlinear clustering do not seem to play a significant role in our analysis. We constrain the growth rate of structure via the redshift-space distortion parameter β at two median redshifts, β(bar z=0.32)=0.599+0.134-0.124 and β(bar z=0.54)=0.457+0.056-0.054, with a precision that is competitive with state-of-the-art galaxy-clustering results. While the high-redshift constraint perfectly agrees with model expectations, we observe a mild 2σ deviation at bar z=0.32, which increases to 3σ when the data is restricted to the lowest available redshift range of 0.15

  3. Luminosity Loss due to Beam Distortion and the Beam-Beam Instability

    CERN Document Server

    Wu, Juhao; Raubenheimer, Tor O; Seryi, Andrei; Sramek, Christopher K

    2005-01-01

    In a linear collider, sources of emittance dilution such as transverse wakefields or dispersive errors will couple the vertical phase space to the longitudinal position within the beam (the so-called ‘banana effect'). When the Intersection Point (IP) disruption parameter is large, these beam distortions will be amplified by a single bunch kink instability which will lead to luminosity loss. We study this phenomena both analytically using linear theory and via numerical simulation. In particular, we examine the dependence of the luminosity loss on the wavelength of the beam distortions and the disruption parameter. This analysis may prove useful when optimizing the vertical disruption parameter for luminosity operation with given beam distortions.

  4. A semi-discretized thin-walled beam element including distortion

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Jönsson, Jeppe

    2013-01-01

    An advanced thin-walled beam element including distortion of the cross section is presented. The formulation is based on a generalization of the classical Vlasov beam theory for analysis of open and closed thin-walled cross sections by including distortional displacements.The beam element...... formulation utilizes a semidiscretization approach in which the cross section is discretized into wall elements and the analytical solutions of the related GBT beam equations are used as displacement functions in the axial direction. Thus the beam element contains the semi-analytical solutions. In a number...... of related publications the authors have recently presented the semi-discretization approach and the analytical solution of the generalized beam equations. An illustrative example showing the validity and the accuracy of the developed distortional semi-discretized thin-walled beam element is given...

  5. Meet the 'entangled' fieldworker - Distorted (re)presentations in tourism research

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    Tourism research has recently been informed by non-representational theories to highlight the socio-material, embodied and heterogeneous composition of tourist experiences. These advances have contributed to further reflexivity and called for novel ways to animate representations....... On this background, this paper develops the notion ‘distorted representation’ to illustrate that blurred and obscure photos can in fact be intelligible and sensible in understanding tourism. Through an exploration of the overwhelmed and unintended practices of visual fieldwork, distorted representation illustrates...... how photographic materialities, performativities and sensations contribute to new tourism knowledges. While highlighting the potential of distorted representation, the paper posits a cautionary note in regards to the influential role of academic journals in determining the qualities of visual data...

  6. Jet Engine Fan Response to Inlet Distortions Generated by Ingesting Boundary Layer Flow

    Science.gov (United States)

    Giuliani, James Edward

    . Total pressure profiles at various axial locations are computed to identify the overall distortion pattern, how the distortion evolves through the blade passages and mixes out downstream of the blades, and where any critical performance concerns might be. Stall cells are identified that are stationary in the absolute frame and are fixed to the inlet distortion. Flow paths around the blades are examined to study the stall mechanism. Rather than a static airfoil stall, it is observed that the non-uniform pressure loading promotes a three-dimensional dynamic stall. The stall occurs at a point of rapid incidence angle oscillation, observed when a blade passes through the distortion, and re-attaches when the blade leaves the distortion.

  7. Digital holographic interferometer with correction of distortions

    Science.gov (United States)

    Sevryugin, A. A.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Y.

    2015-10-01

    The paper considers the use of holographic interferometer for hologram re-recording with correction of distortions. Each optical system contains some beam path deviations, called aberrations of the optical system. They are seen in the resulting interference pattern as a distortion of fringes. While increasing the sensitivity of the interference pattern by N times at the same time we introduce new aberrations, caused by re-recording setup in addition to aberrations that are already presented on the interferogram, caused by initial recording, also multiplied by N times. In this experiment we decided to use a modified setup with spatially combined interferograms with use of matrix spatial light modulator and digital image processing of the interferograms recorded by CCD or CMOS camera.

  8. Flow distortion on boom mounted cup anemometers

    DEFF Research Database (Denmark)

    Lindelöw, Per Jonas Petter; Friis Pedersen, Troels; Gottschall, Julia

    in the measurement of wind turbine power performance, wind resource assessment and for providing purposeful in-field comparisons between different sensors, e.g. lidar anemometers. With the proposed method, direction dependent errors can be extracted and the mast flow distortion effect on the wind measurements......In this report we investigate on wind direction dependent errors in the measurement of the horizontal wind speed by boom mounted cup anemometers. The boom mounting on the studied lattice tower is performed according to IEC standard design rules, yet, larger deviations than predicted by flow models...... are observed. The errors on the measurements are likely caused by an underestimation of the flow distortions around the tower. In this paper an experimental method for deriving a correction formula and an in-field calibration is suggested. The method is based on measurements with two cup anemometers mounted...

  9. Lawful Distortion of Consumers’ Economic Behaviour

    DEFF Research Database (Denmark)

    Trzaskowski, Jan

    2016-01-01

    The Unfair Commercial Practices Directive prohibits unfair business-to-consumer commercial practices with a view to protect consumers’ economic interests. In a market economy such regulation cannot protect the economic interests of all consumers in all situations – there must inevitably be some...... ‘collateral damage’. In that vein this article discusses situations where consumers may have their economic behaviour distorted by commercial practices that are not unfair under the Directive. It is expected that many consumers will make relatively good decisions most of the time...... Visitors’). The article suggests how behavioural sciences may be applied to understand these situations in order to protect more consumers from having their economic behaviour distorted by commercial practices. It is suggested that per se prohibitions may be advantageous in some instances as long...

  10. The cognitive neuroscience of memory distortion.

    Science.gov (United States)

    Schacter, Daniel L; Slotnick, Scott D

    2004-09-30

    Memory distortion occurs in the laboratory and in everyday life. This article focuses on false recognition, a common type of memory distortion in which individuals incorrectly claim to have encountered a novel object or event. By considering evidence from neuropsychology, neuroimaging, and electrophysiology, we address three questions. (1) Are there patterns of neural activity that can distinguish between true and false recognition? (2) Which brain regions contribute to false recognition? (3) Which brain regions play a role in monitoring or reducing false recognition? Neuroimaging and electrophysiological studies suggest that sensory activity is greater for true recognition compared to false recognition. Neuropsychological and neuroimaging results indicate that the hippocampus and several cortical regions contribute to false recognition. Evidence from neuropsychology, neuroimaging, and electrophysiology implicates the prefrontal cortex in retrieval monitoring that can limit the rate of false recognition.

  11. Memory Distortion and False Memory Creation

    OpenAIRE

    Loftus, Elizabeth

    1996-01-01

    Scientific work on memory distortion has captured the attention of the the wider mental health field, of the legal profession, and of the general public. One reason is this: In the last decade, hundreds if not thousands of patients have emerged from psychotherapy accusing their fathers and mothers, their uncles and grandfathers, their former neighbors, their former teachers and therapists, and countless others, of sexually abusing them years before. The patients often claim that they have rep...

  12. Body image distortions in healthy adults.

    Science.gov (United States)

    Fuentes, Christina T; Longo, Matthew R; Haggard, Patrick

    2013-10-01

    Distortions of body image have often been investigated in clinical disorders. Much of this literature implicitly assumes healthy adults maintain an accurate body image. We recently developed a novel, implicit, and quantitative measure of body image - the Body Image Task (BIT). Here, we report a large-scale analysis of performance on this task by healthy adults. In both an in-person and an online version of the BIT, participants were presented with an image of a head as an anchoring stimulus on a computer screen, and told to imagine that the head was part of a mirror image of themselves in a standing position. They were then instructed to judge where, relative to the head, each of several parts of their body would be located. The relative positions of each landmark can be used to construct an implicit perceptual map of bodily structure. We could thus measure the internally-stored body image, although we cannot exclude contributions from other representations. Our results show several distortions of body image. First, we found a large and systematic over-estimation of width relative to height. These distortions were similar for both males and females, and did not closely track the idiosyncrasies of individual participant's own bodies. Comparisons of individual body parts showed that participants overestimated the width of their shoulders and the length of their upper arms, relative to their height, while underestimating the lengths of their lower arms and legs. Principal components analysis showed a clear spatial structure to the distortions, suggesting spatial organisation and segmentation of the body image into upper and lower limb components that are bilaterally integrated. These results provide new insight into the body image of healthy adults, and have implications for the study and rehabilitation of clinical populations. © 2013.

  13. TOTAL HARMONIC DISTORTION ANALYSIS OF MATRIX CONVERTER

    OpenAIRE

    K. Kandan; Senthilkumar,K.; Dhivya, K.

    2016-01-01

    This paper deals with the validation and design analysis of Matrix converter for variable frequency using mathematical equations. The analysis was done using Venturini modulation algorithm. The PI controller is used for Matrix converter to reduce Total Harmonic Distortion (THD) in the output current. The comparative study is done for open loop and closed loop PI compensation in MATLAB-Simulink. Furthermore, the output waveforms are produced with significant reduction in the Total Harmonic Dis...

  14. [Signal analysis and spectrum distortion correction for tunable diode laser absorption spectroscopy system].

    Science.gov (United States)

    Bao, Wei-Yi; Zhu, Yong; Chen, Jun; Chen, Jun-Qing; Liang, Bo

    2011-04-01

    In the present paper, the signal of a tunable diode laser absorption spectroscopy (TDLAS) trace gas sensing system, which has a wavelength modulation with a wide range of modulation amplitudes, is studied based on Fourier analysis method. Theory explanation of spectrum distortion induced by laser intensity amplitude modulation is given. In order to rectify the spectrum distortion, a method of synchronous amplitude modulation suppression by a variable optical attenuator is proposed. To validate the method, an experimental setup is designed. Absorption spectrum measurement experiments on CO2 gas were carried out. The results show that the residual laser intensity modulation amplitude of the experimental system is reduced to -0.1% of its original value and the spectrum distortion improvement is 92% with the synchronous amplitude modulation suppression. The modulation amplitude of laser intensity can be effectively reduced and the spectrum distortion can be well corrected by using the given correction method and system. By using a variable optical attenuator in the TDLAS (tunable diode laser absorption spectroscopy) system, the dynamic range requirements of photoelectric detector, digital to analog converter, filters and other aspects of the TDLAS system are reduced. This spectrum distortion correction method can be used for online trace gas analyzing in process industry.

  15. New Adaptive Image Quality Assessment Based on Distortion Classification

    Directory of Open Access Journals (Sweden)

    Xin JIN

    2014-01-01

    Full Text Available This paper proposes a new adaptive image quality assessment (AIQA method, which is based on distortion classifying. AIQA contains two parts, distortion classification and image quality assessment. Firstly, we analysis characteristics of the original and distorted images, including the distribution of wavelet coefficient, the ratio of edge energy and inner energy of the differential image block, we divide distorted images into White Noise distortion, JPEG compression distortion and fuzzy distortion. To evaluate the quality of first two type distortion images, we use pixel based structure similarity metric and DCT based structural similarity metric respectively. For those blurriness pictures, we present a new wavelet-based structure similarity algorithm. According to the experimental results, AIQA takes the advantages of different structural similarity metrics, and it’s able to simulate the human visual perception effectively.

  16. Cognitive Distortions in Depressed Women: Trait, or State Dependent?

    Directory of Open Access Journals (Sweden)

    Sedat BATMAZ

    2015-12-01

    Conclusion: The results have revealed that self-criticism, helplessness, hopelessness and preoccupation with danger related distortions had trait-like features, whereas self-blame related distortions were state dependent. This has clinical implications for the psychotherapeutic treatment of cognitive distortions in depression. Specifically, self-criticism related distortions should be managed during cognitive therapy for depression since the other subscales seem rather problematic. [JCBPR 2015; 4(3.000: 147-152

  17. Spatial Distortion in MRI-Guided Stereotactic Procedures: Evaluation in 1.5-, 3- and 7-Tesla MRI Scanners.

    Science.gov (United States)

    Neumann, Jan-Oliver; Giese, Henrik; Biller, Armin; Nagel, Armin M; Kiening, Karl

    2015-01-01

    Magnetic resonance imaging (MRI) is replacing computed tomography (CT) as the main imaging modality for stereotactic transformations. MRI is prone to spatial distortion artifacts, which can lead to inaccuracy in stereotactic procedures. Modern MRI systems provide distortion correction algorithms that may ameliorate this problem. This study investigates the different options of distortion correction using standard 1.5-, 3- and 7-tesla MRI scanners. A phantom was mounted on a stereotactic frame. One CT scan and three MRI scans were performed. At all three field strengths, two 3-dimensional sequences, volumetric interpolated breath-hold examination (VIBE) and magnetization-prepared rapid acquisition with gradient echo, were acquired, and automatic distortion correction was performed. Global stereotactic transformation of all 13 datasets was performed and two stereotactic planning workflows (MRI only vs. CT/MR image fusion) were subsequently analysed. Distortion correction on the 1.5- and 3-tesla scanners caused a considerable reduction in positional error. The effect was more pronounced when using the VIBE sequences. By using co-registration (CT/MR image fusion), even a lower positional error could be obtained. In ultra-high-field (7 T) MR imaging, distortion correction introduced even higher errors. However, the accuracy of non-corrected 7-tesla sequences was comparable to CT/MR image fusion 3-tesla imaging. MRI distortion correction algorithms can reduce positional errors by up to 60%. For stereotactic applications of utmost precision, we recommend a co-registration to an additional CT dataset. © 2015 S. Karger AG, Basel.

  18. Cognitive Distortions and Autonomy among Chinese University Students

    Science.gov (United States)

    Zhang, Li-fang

    2008-01-01

    The purpose of this study was to examine the roles of university students' cognitive distortions in their sense of autonomy. One hundred and three third-year university students from Shanghai, The People's Republic of China, responded to the Cognitive Distortion Scales [Briere, J. (2000). "Cognitive Distortion Scales: Professional…

  19. High-order-harmonic generation from field-distorted orbitals

    DEFF Research Database (Denmark)

    Spiewanowski, Maciek; Etches, Adam; Madsen, Lars Bojer

    2013-01-01

    We investigate the effect on high-order-harmonic generation of the distortion of molecular orbitals by the driving laser field. Calculations for high-order-harmonic generation including orbital distortion are performed for N2. Our results allow us to suggest that field distortion is the reason why...

  20. Centi-pixel accurate real-time inverse distortion correction

    CSIR Research Space (South Africa)

    De Villiers, Johan P

    2008-11-01

    Full Text Available Inverse distortion is used to create an undistorted image from a distorted image. For each pixel in the undistorted image it is required to determine which pixel in the distorted image should be used. However the process of characterizing a lens...

  1. Perceptual and Conceptual Distortions of Implicit Hand Maps

    Directory of Open Access Journals (Sweden)

    Matthew R. Longo

    2015-12-01

    Full Text Available Recent studies have revealed that human position sense relies on a massively distorted representation of hand size and shape. By comparing the judged location of landmarks on an occluded hand, Longo and Haggard (2010 constructed implicit perceptual maps of represented hand structure, showing large underestimation of finger length and overestimation of hand width. Here, we investigated the contribution of two potential sources of distortions to such effects: perceptual distortions reflecting spatial warping of the representation of bodily tissue itself, perhaps reflecting distortions of somatotopic cortical maps, and conceptual distortions reflecting mistaken beliefs about the locations of different landmarks within the body. In Experiment 1 we compared distorted hand maps to a task in which participants explicitly judged the location of their knuckles in a hand silhouette. The results revealed the conceptual distortions are responsible for at least part of the underestimation of finger length, but cannot explain overestimation of hand width. Experiment 2 compared distortions of the participant’s own hand based on position sense with a prosthetic hand based on visual memory. Underestimation of finger length was found for both hands, providing further evidence that it reflects a conceptual distortion. In contrast, overestimation of hand width was specific to representation of the participant’s own hand, confirming it reflects a perceptual distortion. Together, these results suggest that distorted body representations do not reflect a single underlying cause. Rather, both perceptual and conceptual distortions contribute to the overall configuration of the hand representation.

  2. Spectral distortion in a radially inhomogeneous cosmology

    Science.gov (United States)

    Caldwell, R. R.; Maksimova, N. A.

    2013-11-01

    The spectral distortion of the cosmic microwave background blackbody spectrum in a radially inhomogeneous space-time, designed to exactly reproduce a ΛCDM expansion history along the past light cone, is shown to exceed the upper bound established by COBE-FIRAS by a factor of approximately 3700. This simple observational test helps uncover a slew of pathological features that lie hidden inside the past light cone, including a radially contracting phase at decoupling and, if followed to its logical extreme, a naked singularity at the radially inhomogeneous big bang.

  3. Adult attachment, cognitive distortions, and views of self, others, and the future among child molesters.

    Science.gov (United States)

    Wood, Eric; Riggs, Shelley

    2009-09-01

    A conceptual framework derived from attachment theory was tested examining adult romantic attachment; views of self, world/others, and the future; and cognitive distortions in a sample of 96 child molesters receiving sex offender treatment and 92 nonoffending males. Results showed a significant main effect for child molester status, with nonoffending controls reporting fewer negative perceptions of self, others, and the future; and fewer cognitive distortions regarding adult-child sex. With the exception of views of others, significant interactions were also found between child molester status and attachment categories. However, the patterns of interactions were theoretically counterintuitive and illustrated areas for future research. Overall, the findings supported theoretically based hypotheses, suggesting that attachment theory may be useful in the conceptualization and treatment of child molesters.

  4. Prediction of Part Distortion in Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    R. Allen Miller

    2005-03-30

    The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

  5. Reducing Field Distortion in Magnetic Resonance Imaging

    Science.gov (United States)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2010-01-01

    A concept for a magnetic resonance imaging (MRI) system that would utilize a relatively weak magnetic field provides for several design features that differ significantly from the corresponding features of conventional MRI systems. Notable among these features are a magnetic-field configuration that reduces (relative to the conventional configuration) distortion and blurring of the image, the use of a superconducting quantum interference device (SQUID) magnetometer as the detector, and an imaging procedure suited for the unconventional field configuration and sensor. In a typical application of MRI, a radio-frequency pulse is used to excite precession of the magnetic moments of protons in an applied magnetic field, and the decaying precession is detected for a short time following the pulse. The precession occurs at a resonance frequency proportional to the strengths of the magnetic field and the proton magnetic moment. The magnetic field is configured to vary with position in a known way; hence, by virtue of the aforesaid proportionality, the resonance frequency varies with position in a known way. In other words, position is encoded as resonance frequency. MRI using magnetic fields weaker than those of conventional MRI offers several advantages, including cheaper and smaller equipment, greater compatibility with metallic objects, and higher image quality because of low susceptibility distortion and enhanced spin-lattice-relaxation- time contrast. SQUID MRI is being developed into a practical MRI method for applied magnetic flux densities of the order of only 100 T

  6. Rotational distortion in conventional allometric analyses.

    Science.gov (United States)

    Packard, Gary C

    2011-08-01

    Three data sets from the recent literature were submitted to new analyses to illustrate the rotational distortion that commonly accompanies traditional allometric analyses and that often causes allometric equations to be inaccurate and misleading. The first investigation focused on the scaling of evaporative water loss to body mass in passerine birds; the second was concerned with the influence of body size on field metabolic rates of rodents; and the third addressed interspecific variation in kidney mass among primates. Straight lines were fitted to logarithmic transformations by Ordinary Least Squares and Generalized Linear Models, and the resulting equations then were re-expressed as two-parameter power functions in the original arithmetic scales. The re-expressed models were displayed on bivariate graphs together with tracings for equations fitted directly to untransformed data by nonlinear regression. In all instances, models estimated by back-transformation failed to describe major features of the arithmetic distribution whereas equations fitted by nonlinear regression performed quite well. The poor performance of equations based on models fitted to logarithms can be traced to the increased weight and leverage exerted in those analyses by observations for small species and to the decreased weight and leverage exerted by large ones. The problem of rotational distortion can be avoided by performing exploratory analysis on untransformed values and by validating fitted models in the scale of measurement. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. The impact of harmonic distortion on power transformers operating near the thermal limit

    OpenAIRE

    2009-01-01

    M.Ing. The study looks into the impact of harmonic distortion on power-plant equipment in general, and then focuses on the impact it has on power transformers operating near the thermal limit. The feasibility of the study is firstly evaluated and then the theory on harmonics and transformer losses is analysed. The study had been narrowed down to power transformers due to the high numbers of failures nationally and internationally attributed to unknown causes. A transformer model is then de...

  8. Beyond consistency test of gravity with redshift-space distortions at quasilinear scales

    OpenAIRE

    Taruya, Atsushi; Koyama, Kazuya; Hiramatsu, Takashi; Oka, Akira

    2014-01-01

    Redshift-space distortions (RSDs) offer an attractive method to measure the growth of cosmic structure on large scales, and combining with the measurement of the cosmic expansion history, they can be used as cosmological tests of gravity. With the advent of future galaxy redshift surveys aiming at precisely measuring the RSD, an accurate modeling of RSD going beyond linear theory is a critical issue in order to detect or disprove small deviations from general relativity (GR). While several im...

  9. Pressure measurements in a rapidly sheared turbulent wall layer

    Science.gov (United States)

    Diwan, Sourabh; Morrison, Jonathan

    2014-11-01

    The aim of the present work is to improve understanding of the role of pressure fluctuations in the generation of coherent structures in wall-bounded turbulent flows, with particular regard to the rapid and slow source terms. The work is in part motivated by the recent numerical simulations of Sharma et al. (Phy. Fluids, 23, 2011), which showed the importance of pressure fluctuations (and their spatial gradients) in the dynamics of large-scale turbulent motions. Our experimental design consists of first generating a shearless boundary layer in a wind tunnel by passing a grid-generated turbulent flow over a moving floor whose speed is matched to the freestream velocity, and then shearing it rapidly by passing it over a stationary floor further downstream. Close to the leading edge of the stationary floor, the resulting flow is expected to satisfy the approximations of the Rapid Distortion Theory and therefore would be an ideal candidate for studying linear processes in wall turbulence. We carry out pressure measurements on the wall as well as within the flow - the former using surface mounted pressure transducers and the latter using a static pressure probe similar in design to that used by Tsuji et al. (J. Fluid. Mech. 585, 2007). We also present a comparison between the rapidly sheared flow and a more conventional boundary layer subjected to a turbulent free stream. We acknowledge the financial support from EPSRC (Grant No. EP/I037938).

  10. JET ENGINE INLET DISTORTION SCREEN AND DESCRIPTOR EVALUATION

    Directory of Open Access Journals (Sweden)

    Jiří Pečinka

    2017-02-01

    Full Text Available Total pressure distortion is one of the three basic flow distortions (total pressure, total temperature and swirl distortion that might appear at the inlet of a gas turbine engine (GTE during operation. Different numerical parameters are used for assessing the total pressure distortion intensity and extent. These summary descriptors are based on the distribution of total pressure in the aerodynamic interface plane. There are two descriptors largely spread around the world, however, three or four others are still in use and can be found in current references. The staff at the University of Defence decided to compare the most common descriptors using basic flow distortion patterns in order to select the most appropriate descriptor for future department research. The most common descriptors were identified based on their prevalence in widely accessible publications. The construction and use of these descriptors are reviewed in the paper. Subsequently, they are applied to radial, angular, and combined distortion patterns of different intensities and with varied mass flow rates. The tests were performed on a specially designed test bench using an electrically driven standalone industrial centrifugal compressor, sucking air through the inlet of a TJ100 small turbojet engine. Distortion screens were placed into the inlet channel to create the desired total pressure distortions. Of the three basic distortions, only the total pressure distortion descriptors were evaluated. However, both total and static pressures were collected using a multi probe rotational measurement system.

  11. Prediction of transmission distortion for wireless video communication: analysis.

    Science.gov (United States)

    Chen, Zhifeng; Wu, Dapeng

    2012-03-01

    Transmitting video over wireless is a challenging problem since video may be seriously distorted due to packet errors caused by wireless channels. The capability of predicting transmission distortion (i.e., video distortion caused by packet errors) can assist in designing video encoding and transmission schemes that achieve maximum video quality or minimum end-to-end video distortion. This paper is aimed at deriving formulas for predicting transmission distortion. The contribution of this paper is twofold. First, we identify the governing law that describes how the transmission distortion process evolves over time and analytically derive the transmission distortion formula as a closed-form function of video frame statistics, channel error statistics, and system parameters. Second, we identify, for the first time, two important properties of transmission distortion. The first property is that the clipping noise, which is produced by nonlinear clipping, causes decay of propagated error. The second property is that the correlation between motion-vector concealment error and propagated error is negative and has dominant impact on transmission distortion, compared with other correlations. Due to these two properties and elegant error/distortion decomposition, our formula provides not only more accurate prediction but also lower complexity than the existing methods.

  12. Design of the new rigid endoscope distortion measurement system

    Science.gov (United States)

    Zhai, Xiaohao; Liu, Xiaohua; Liu, Ming; Hui, Mei; Dong, Liquan; Zhao, Yuejin; Wang, Yakun; Li, Yonghui; Zhou, Peng

    2015-08-01

    Endoscopic imaging quality affects industrial safety and medical security. Rigid endoscope distortion is of great signification as one of optical parameters to evaluate the imaging quality. This paper introduces a new method of rigid endoscope distortion measurement, which is different from the common methods with low accuracy and fussy operation. It contains a Liquid Crystal Display (LCD) to display the target, a CCD to obtain the images with distortion, and a computer to process the images. The LCD is employed instead of common white screen. The autonomous control system of LCD makes it showing the test target designed for distortion, and its parameter is known. LCD control system can change the test target to satisfy the different demand for accuracy, which avoids replacing target frequently. The test system also contains a CCD to acquire images in the exit pupil position of rigid endoscope. Rigid endoscope distortion is regarded as centrosymmetric, and the MATLAB software automatically measures it by processing the images from CCD. The MATLAB software compares target images with that without distortion on LCD and calculates the results. Relative distortion is obtained at different field of view (FOV) radius. The computer plots the curve of relative distortion, abscissa means radius of FOV, ordinate means relative distortion. The industry standard shows that, the distortion at 70% field of view is pointed on the curve, which can be taken as an evaluation standard. This new measuring method achieves advantages of high precision, high degree of intelligence, excellent repeatability and gets calculation results quickly.

  13. Harmonic analysis for the characterization and correction of geometric distortion in MRI.

    Science.gov (United States)

    Tadic, Tony; Jaffray, David A; Stanescu, Teodor

    2014-11-01

    Magnetic resonance imaging (MRI) is gaining widespread use in radiation therapy planning, patient setup verification, and real-time guidance of radiation delivery. Successful implementation of these technologies relies on the development of simple and efficient methods to characterize and monitor the geometric distortions arising due to system imperfections and gradient nonlinearities. To this end, the authors present the theory and validation of a novel harmonic approach to the quantification of system-related distortions in MRI. The theory of spatial encoding in MRI is applied to demonstrate that the 3D distortion vector field (DVF) is given by the solution of a second-order boundary value problem (BVP). This BVP is comprised of Laplace's equation and a limited measurement of the distortion on the boundary of a specified region of interest (ROI). An analytical series expansion solving this BVP within a spherical ROI is obtained, and a statistical uncertainty analysis is performed to determine how random errors in the boundary measurements propagate to the ROI interior. This series expansion is then evaluated to obtain volumetric DVF mappings that are compared to reference data obtained on a 3 T full-body scanner. This validation is performed within two spheres of 20 cm diameter (one centered at the scanner origin and the other offset +3 cm along each of the transverse directions). Initially, a high-order mapping requiring measurements at 5810 boundary points is used. Then, after exploring the impact of the boundary sampling density and the effect of series truncation, a reduced-order mapping requiring measurements at 302 boundary points is evaluated. The volumetric DVF mappings obtained from the harmonic analysis are in good agreement with the reference data. Following distortion correction using the high-order mapping, the authors estimate a reduction in the mean distortion magnitude from 0.86 to 0.42 mm and from 0.93 to 0.39 mm within the central and offset

  14. Interpreting large-scale redshift-space distortion measurements

    Science.gov (United States)

    Samushia, L.; Percival, W. J.; Raccanelli, A.

    2012-03-01

    The simplest theory describing large-scale redshift-space distortions (RSD), based on linear theory and distant galaxies, depends on the growth of cosmological structure, suggesting that strong tests of general relativity can be constructed from galaxy surveys. As data sets become larger and the expected constraints more precise, the extent to which the RSD follow the simple theory needs to be assessed in order that we do not introduce systematic errors into the tests by introducing inaccurate simplifying assumptions. We study the impact of the sample geometry, non-linear processes and biases induced by our lack of understanding of the radial galaxy distribution on RSD measurements. Using Large Suite of Dark Matter Simulations of the Sloan Digital Sky Survey II (SDSS-II) luminous red galaxy data, these effects are shown to be important at the level of 20 per cent. Including them, we can accurately model the recovered clustering in these mock catalogues on scales 30-200 h-1 Mpc. Applying this analysis to robustly measure parameters describing the growth history of the Universe from the SDSS-II data gives f(z= 0.25)σ8(z= 0.25) = 0.3512 ± 0.0583 and f(z= 0.37)σ8(z= 0.37) = 0.4602 ± 0.0378 when no prior is imposed on the growth rate, and the background geometry is assumed to follow a Λ cold dark matter (ΛCDM) model with the Wilkinson Microwave Anisotropy Probe (WMAP)+Type Ia supernova priors. The standard WMAP constrained ΛCDM model with general relativity predicts f(z= 0.25)σ8(z= 0.25) = 0.4260 ± 0.0141 and f(z= 0.37)σ8(z= 0.37) = 0.4367 ± 0.0136, which is fully consistent with these measurements.

  15. PROTECTION OF HOUSEHOLD APPLIANCES INDUCTION MOTORS AGAINST OVERCURRENT TAKING INTO ACCOUNT NONLINEAR DISTORTION OF PHASE CURRENT

    Directory of Open Access Journals (Sweden)

    A.G. Sereda

    2015-06-01

    Full Text Available Purpose. Theoretical justification and engineering of induction motors heat protection method from overload currents taking into account nonlinear distortion of the phase current and implementation as a microprocessor device functioning algorithm. Methodology. To solve the problem used the theory of the representing complex harmonic oscillations analog signals expansion into the oscillation spectrum forming elementary harmonic components in order to compare their properties by applying the theory of discrete signals and systems, as well as methods of spectral analysis and discrete signals filtering. The harmonic analysis versatility is that any periodic signal may be synthesized from harmonic oscillation of certain amplitude, frequency and initial phase. A mathematical model for determining the phase current harmonic content of power supply networks with isolated neutral and non-linear loads types and, as a consequence, the distortion of sinusoidal phase current change is developed by multiplying the analog current in time dependency on the grate delta-function with different sampling intervals, in which the use of simple and widely used in relay protection units, in particular electronic overcurrent relays, mathematical operations of integration squares instantaneous current allows the most in harmony with the mathematical tools to build other network protection types. Findings. The necessity to increase the sensitivity of the induction motors heat protection from overload currents taking into account nonlinear distortion of the phase currents is proved. By nonlinear distortion harmonic analysis of the phase currents the motor protection reliability increasing provided by taking into account the higher harmonic components of the phase currents, which causes to additional losses and heating of the stator winding. It uses the simplest and widely used in protective relaying mathematical apparatus determining of most significant higher harmonics

  16. Distortion Exponent in MIMO Channels with Feedback

    CERN Document Server

    Gunduz, Deniz; Poor, H Vincent

    2009-01-01

    The transmission of a Gaussian source over a block-fading multiple antenna channel in the presence of a feedback link is considered. The feedback link is assumed to be an error and delay free link of capacity 1 bit per channel use. Under the short-term power constraint, the optimal exponential behavior of the end-to-end average distortion is characterized for all source-channel bandwidth ratios. It is shown that the optimal transmission strategy is successive refinement source coding followed by progressive transmission over the channel, in which the channel block is allocated dynamically among the layers based on the channel state using the feedback link as an instantaneous automatic repeat request (ARQ) signal.

  17. Correcting underwater images distorted by surface waves

    Science.gov (United States)

    Savchenko, V. V.; Osadchy, V. Yu.; Levin, I. M.

    2008-12-01

    An experiment on the correction of underwater images distorted by waves at the air-water interface was conducted using a laboratory modeling installation intended for experimental examination of light and image transfer across a water surface covered with waves. A digital color camera was used for the simultaneous formation of the image of the underwater test object through the disturbed surface and of the superimposed glitter pattern. Both images are spectrally separated. Processing the glitter pattern makes it possible to obtain the values of the surface slopes at a limited number of points and to use these slopes for retrieval of image fragments. The total corrected image is formed by integration of about 300 partially corrected fragments. This image is close to that obtained through a wave-free water surface.

  18. Globalization, tax distortions and public sector retrenchment

    DEFF Research Database (Denmark)

    Andersen, Torben M.; Sørensen, Allan

    It is widely perceived that globalization is a threat to tax financed public sector activities. The argument is that public activities (public consumption and transfers) financed by income taxes distort labour markets and cause higher wages and thus a loss of competitiveness. Since this link...... income taxation unambiguously worsens wage competitiveness, it does not follow that marginal costs of public funds increase with product market integration due to gains from trade. Moreover, non-cooperative fiscal policies do not have a race-to-the-bottom bias despite that taxes harm competitiveness....... In fact we identify an expansionary bias in …scal policies that is likely to increase with globalization when taxes finance either public consumption or transfers....

  19. Focal region fields of distorted reflectors

    Science.gov (United States)

    Buris, N. E.; Kauffman, J. F.

    1988-01-01

    The problem of the focal region fields scattered by an arbitrary surface reflector under uniform plane wave illumination is solved. The physical optics (PO) approximation is used to calculate the current induced on the reflector. The surface of the reflector is described by a number of triangular domain-wise 5th degree bivariate polynomials. A 2-dimensional Gaussian quadrature is employed to numerically evaluate the integral expressions of the scattered fields. No Freshnel or Fraunhofer zone approximations are made. The relation of the focal fields problem to surface compensation techniques and other applications are mentioned. Several examples of distorted parabolic reflectors are presented. The computer code developed is included, together with instructions on its usage.

  20. Doing cognitive distortions: a discursive psychology analysis of sex offender treatment talk.

    Science.gov (United States)

    Auburn, Timothy; Lea, Susan

    2003-06-01

    Theories of sex offending have for several years relied upon the notion of cognitive distortions as an important cause of sexual offending. In this study we critique this notion and suggest that the sort of phenomenon addressed by cognitive distortions is better understood by adopting a discursive psychology approach. In this approach, talk is regarded as occasioned and action oriented. Thus 'cognitive distortions' are conceptualized as something people do rather than something that people have. Sessions from a prison-based sex offender treatment programme were taped and transcribed. A discursive psychology analysis was conducted on those sessions relating to offenders' first accounts of their offences. Our analysis suggests that offenders utilize a particular narrative organization to manage their blame and responsibility for the offence. This organization is based on a first part which is oriented to quotidian precursors to the offence and an immediately following second which is oriented to a sudden shift in the definition of the situation. The implications of this analysis are discussed, in relation to the status of cognitive distortions and treatment.

  1. Breathing mode distortion and magnetic order in rare-earth nickelates RNiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Hampel, Alexander; Ederer, Claude [Materials Theory, ETH Zuerich (Switzerland)

    2016-07-01

    Rare-earth nickelate perovskites display a rich and not yet fully understood phase diagram, where all RNiO{sub 3} compounds with R from Sm to Lu undergo a non-magnetic metal-insulator transition (MIT). This transition is connected to a lattice distortion, which can be described as breathing mode of the oxygen octahedra surrounding the Ni cations. Between 100-250 K the RNiO{sub 3} compounds undergo a magnetic transition to an antiferromagnetic (AFM) state, with a wave-vector k= [(1)/(4) (1)/(4) (1)/(4)] relative to the underlying simple cubic perovskite structure. Here, we use density functional theory and its extensions (DFT+U, DFT+DMFT) together with distortion mode analysis to explore the interplay between lattice distortions, magnetic order, and the strength of the local Coulomb interaction U in rare earth nickelates. Our results show a strong dependency of the breathing mode amplitude on the magnetic order, with a much larger breathing mode obtained for the AFM state compared to the ferromagnetic case. Furthermore, we demonstrate that DFT+U is able to capture the correct trends of the lattice distortions across the nickelate series.

  2. Peak distortion effects in analytical ion chromatography.

    Science.gov (United States)

    Wahab, M Farooq; Anderson, Jordan K; Abdelrady, Mohamed; Lucy, Charles A

    2014-01-07

    The elution profile of chromatographic peaks provides fundamental understanding of the processes that occur in the mobile phase and the stationary phase. Major advances have been made in the column chemistry and suppressor technology in ion chromatography (IC) to handle a variety of sample matrices and ions. However, if the samples contain high concentrations of matrix ions, the overloaded peak elution profile is distorted. Consequently, the trace peaks shift their positions in the chromatogram in a manner that depends on the peak shape of the overloading analyte. In this work, the peak shapes in IC are examined from a fundamental perspective. Three commercial IC columns AS16, AS18, and AS23 were studied with borate, hydroxide and carbonate as suppressible eluents. Monovalent ions (chloride, bromide, and nitrate) are used as model analytes under analytical (0.1 mM) to overload conditions (10-500 mM). Both peak fronting and tailing are observed. On the basis of competitive Langmuir isotherms, if the eluent anion is more strongly retained than the analyte ion on an ion exchanger, the analyte peak is fronting. If the eluent is more weakly retained on the stationary phase, the analyte peak always tails under overload conditions regardless of the stationary phase capacity. If the charge of the analyte and eluent anions are different (e.g., Br(-) vs CO3(2-)), the analyte peak shapes depend on the eluent concentration in a more complex pattern. It was shown that there are interesting similarities with peak distortions due to strongly retained mobile phase components in other modes of liquid chromatography.

  3. A Cognitive Distortions and Deficits Model of Suicide Ideation.

    Science.gov (United States)

    Fazakas-DeHoog, Laura L; Rnic, Katerina; Dozois, David J A

    2017-05-01

    Although cognitive distortions and deficits are known risk factors for the development and escalation of suicide ideation and behaviour, no empirical work has examined how these variables interact to predict suicide ideation. The current study proposes an integrative model of cognitive distortions (hopelessness and negative evaluations of self and future) and deficits (problem solving deficits, problem solving avoidance, and cognitive rigidity). To test the integrity of this model, a sample of 397 undergraduate students completed measures of deficits, distortions, and current suicide ideation. A structural equation model demonstrated excellent fit, and findings indicated that only distortions have a direct effect on suicidal thinking, whereas cognitive deficits may exert their effects on suicide ideation via their reciprocal relation with distortions. Findings underscore the importance of both cognitive distortions and deficits for understanding suicidality, which may have implications for preventative efforts and treatment.

  4. Study Of Gear Teeth Distortions Due To Heat Treatment

    Directory of Open Access Journals (Sweden)

    V. Khade

    2015-02-01

    Full Text Available Abstract The work aims to study the distortion occurred due to heat treatment on the Gear teeth. The paper studies various causes of distortion control techniques to eliminate distortion which includes changes in design selection of material heat treatment process mainly due to quenching that includes cooling rates quenching mediums fixtures. An experimental study and results conducted for the effects of the distortion on the Gear teeth and to reduce the distortion with certain changes design modification resulting in shape amp size changes phase changes changes in hardness microstructure and residual stresses. It is observed that adequate velocity of quench oil around the component to be heat treated ensures uniform amp desired cooling rate as per heat treatment cycle. Modification in design of baffles achieved the adequate velocity and minimization of distortion. Also Fixtures for holding finished parts or assemblies during heat treatment may be either support or restraint type to control dimensional relations during aging.

  5. A Cognitive Distortions and Deficits Model of Suicide Ideation

    Directory of Open Access Journals (Sweden)

    Laura L. Fazakas-DeHoog

    2017-05-01

    Full Text Available Although cognitive distortions and deficits are known risk factors for the development and escalation of suicide ideation and behaviour, no empirical work has examined how these variables interact to predict suicide ideation. The current study proposes an integrative model of cognitive distortions (hopelessness and negative evaluations of self and future and deficits (problem solving deficits, problem solving avoidance, and cognitive rigidity. To test the integrity of this model, a sample of 397 undergraduate students completed measures of deficits, distortions, and current suicide ideation. A structural equation model demonstrated excellent fit, and findings indicated that only distortions have a direct effect on suicidal thinking, whereas cognitive deficits may exert their effects on suicide ideation via their reciprocal relation with distortions. Findings underscore the importance of both cognitive distortions and deficits for understanding suicidality, which may have implications for preventative efforts and treatment.

  6. Supporting the Development of a New Health R&D Strategy: A Rapid Review of International Theory and Practice for Norway's HelseOmsorg21.

    Science.gov (United States)

    Grant, Jonathan; Pollitt, Alexandra; Castle-Clarke, Sophie; Cochrane, Gavin; Sondergaard, Susanne; Horvath, Veronika

    2014-01-01

    The HelseOmsorg21 initiative was set up by the Ministry of Health and Care Services to develop a new research and innovation strategy for health and care services in Norway. The HelseOmsorg21 Strategy Group, through the Research Council of Norway which is providing the secretariat for the strategy development, asked RAND Europe to support the strategic review process. RAND Europe's role was to conduct a series of rapid evidence reviews around the recommendations arising from the five working groups that comprise the initiative. The reviews were conducted around networks and collaboration, data linkage and exchange, culture, values and leadership, and incentives for innovation, while capacity building was a recurrent theme throughout. This study presents the rapid evidence reviews, summarising relevant literature and highlighting international examples of particularly relevant or innovative approaches. The issues and ideas identified around each theme are then pulled together in a suggested conceptual representation of the Norwegian health and care research system.

  7. Word Recognition for Temporally and Spectrally Distorted Materials

    DEFF Research Database (Denmark)

    Smith, Sherri L.; Pichora-Fuller, Margaret Kathleen; Wilson, Richard H.

    2012-01-01

    conditions were similar. Conclusions: The present experiments advance our understanding regarding how spectral or temporal distortions of the fine structure of speech affect word recognition in older listeners with and without clinically significant hearing loss. The Speech Intelligibility Index was able...... to predict group differences, but not the effects of distortion. Individual differences in performance were similar across all distortion conditions with both age and hearing loss being implicated. The speech materials needed to be both spectrally and temporally distorted to mimic the effects of age...

  8. A new theory for rapid calculation of the ground pattern of the incident sound intensity produced by a maneuvering jet airplane

    Science.gov (United States)

    Barger, R. L.

    1980-01-01

    An approximate method for computing the jet noise pattern of a maneuvering airplane is described. The method permits one to relate the noise pattern individually to the influences of airplane speed and acceleration, jet velocity and acceleration, and the flight path curvature. The analytic formulation determines the ground pattern directly without interpolation and runs rapidly on a minicomputer. Calculated examples including a climbing turn and a simple climb pattern with a gradual throttling back are presented.

  9. Strip distortion generator for simulating inlet flow distortion in gas turbine engine ground test facilities

    Directory of Open Access Journals (Sweden)

    M. Saleem Yusoof

    2016-12-01

    Full Text Available A methodology has been developed to generate a non-uniform/distorted inlet flow field to test a gas turbine engine in ground test facilities. The distorted flow field is generated by positioning radial and circumferential strips of varying widths upstream of the Aerodynamic Interface Plane. The interacting wakes from these strips are used to generate a given target flow field. The approximate superposition of these wakes is investigated and used to construct the strip arrangement which is subsequently validated by computing the flow field by solving the Navier–Stokes equations. The strip geometry designed using the present methodology is able to produce the target Mach number distribution with a root-mean-square error of 5.06%.

  10. Optical distortions in end-pumped zigzag slab lasers.

    Science.gov (United States)

    Tang, Bing; Zhou, Tangjian; Wang, Dan; Li, Mi

    2015-04-01

    Ray tracing is performed to investigate the optical distortions in the end-pumped, zigzag slab. Optical path differences caused by temperature, slab deformation, and stress birefringence are calculated under uniform pumping; the results show a steep edge in the width dimension and a thermal lens with an effective focal length as short as several meters in the thickness dimension. Dependence of depolarization on total internal reflection phase retardance as well as the slab's cut angle is studied by the Jones matrix technique; results show that although at the pumping power of 10 kW, the mean depolarization of the 2.5  mm×30  mm×150.2  mm Nd:YAG slab is generally below 3%, and it increases rapidly with pumping power. Besides, for the 0°- or 60°-cut slab, an optimal phase retardance range of 5° to 13° exists, in which the depolarization loss can be lower than 0.5%. Finally, experiments on temperature and depolarization measurements verify the numerical results.

  11. Investigating incipient speciation in Arabidopsis lyrata from patterns of transmission ratio distortion.

    Science.gov (United States)

    Leppälä, Johanna; Bokma, Folmer; Savolainen, Outi

    2013-07-01

    Our understanding of the development of intrinsic reproductive isolation is still largely based on theoretical models and thorough empirical studies on a small number of species. Theory suggests that reproductive isolation develops through accumulation of epistatic genic incompatibilities, also known as Bateson-Dobzhansky-Muller (BDM) incompatibilities. We can detect these from marker transmission ratio distortion (TRD) in hybrid progenies of crosses between species or populations, where TRD is expected to result from selection against heterospecific allele combinations in hybrids. TRD may also manifest itself because of intragenomic conflicts or competition between gametes or zygotes. We studied early stage speciation in Arabidopsis lyrata by investigating patterns of TRD across the genome in F2 progenies of three reciprocal crosses between four natural populations. We found that the degree of TRD increases with genetic distance between crossed populations, but also that reciprocal progenies may differ substantially in their degree of TRD. Chromosomes AL6 and especially AL1 appear to be involved in many single- and two-locus distortions, but the location and source of TRD vary between crosses and between reciprocal progenies. We also found that the majority of single- and two-locus TRD appears to have a gametic, as opposed to zygotic, origin. Thus, while theory on BDM incompatibilities is typically illustrated with derived nuclear alleles proving incompatible in hybrid zygotes, our results suggest a prominent role for distortions emerging before zygote formation.

  12. Time perception distortion in neuropsychiatric and neurological disorders.

    Science.gov (United States)

    Teixeira, Silmar; Machado, Sergio; Paes, Flavia; Velasques, Bruna; Silva, Julio Guilherme; Sanfim, Antonio L; Minc, Daniel; Anghinah, Renato; Menegaldo, Luciano L; Salama, Mohamed; Cagy, Mauricio; Nardi, Antonio E; Pöppel, Ernst; Bao, Yan; Szelag, Elzbieta; Ribeiro, Pedro; Arias-Carrión, Oscar

    2013-08-01

    There is no sense organ specifically dedicated to time perception, as there is for other senses such as hearing and vision. However, this subjective sense of time is fundamental to our conception of reality and it creates the temporal course of events in our lives. Here, we explored neurobiological relations from the clinical perspective, examining timing ability in patients with different neurological and psychiatric conditions (e.g. Parkinson's disease, depression, bipolar disorder, anxiety disorders and schizophrenia). The neural bases of present distortions in time perception and temporal information processing still remain poorly understood. We reviewed: a) how the brain is capable of encoding time in different environments and multiple tasks, b) different models of interval timing, c) brain structures and neurotransmitters associated with time perception, d) the relationship between memory and time perception, e) neural mechanisms underlying different theories in neural and mental processes, and f) the relationship between different mental diseases and time perception. Bibliographic research was conducted based on publications over the past thirteen years written in English in the databases Scielo, Pubmed/MEDLINE, ISI Web of Knowledge. The time perceptions research are executed to evaluate time perception in mental diseases and can provide evidence for future clinical applications.

  13. Anomalous Centrifugal Distortion in NH_2

    Science.gov (United States)

    Martin-Drumel, Marie-Aline; Pirali, Olivier; Coudert, L. H.

    2017-06-01

    The NH2 radical spectrum, first observed by Herzberg and Ramsay, is dominated by a strong Renner-Teller effect giving rise to two electronic states: the bent X ^{2}B_1 ground state and the quasi-linear A ^{2}A_1 excited state. The NH2 radical has been the subject of numerous high-resolution investigations and its electronic and ro-vibrational transitions have been measured. Using synchrotron radiation, new rotational transitions have been recently recorded and a value of the rotational quantum number N as large as 26 could be reached. In the X ^{2}B_1 ground state, the NH2 radical behaves like a triatomic molecule displaying spin-rotation splittings. Due to the lightness of the molecule, a strong coupling between the overall rotation and the bending mode arises whose effects increase with N and lead to the anomalous centrifugal distortion evidenced in the new measurements.^d In this talk the Bending-Rotation approach developed to account for the anomalous centrifugal distortion of the water molecule is modified to include spin-rotation coupling and applied to the fitting of high-resolution data pertaining to the ground electronic state of NH2. A preliminary line position analysis of the available data^{c,d} allowed us to account for 1681 transitions with a unitless standard deviation of 1.2. New transitions could also be assigned in the spectrum recorded by Martin-Drumel et al.^d In the talk, the results obtained with the new theoretical approach will be compared to those retrieved with a Watson-type Hamiltonian and the effects of the vibronic coupling between the ground X ^{2}B_1 and the excited A ^{2}A_1 electronic state will be discussed. Herzberg and Ramsay, J. Chem. Phys. 20 (1952) 347 Dressler and Ramsay, Phil. Trans. R. Soc. A 25 (1959) 553 Hadj Bachir, Huet, Destombes, and Vervloet, J. Molec. Spectrosc. 193 (1999) 326 McKellar, Vervloet, Burkholder, and Howard, J. Molec. Spectrosc. 142 (1990) 319 Morino and Kawaguchi, J. Molec. Spectrosc. 182 (1997) 428

  14. Turbulent transport of a passive contaminant in an initially anisotropic turbulence subjected to rapid rotation: an analytical study using linear theory

    Science.gov (United States)

    El Bach, A.; Salhi, A.; Cambon, Claude

    2008-04-01

    The linear effect of rapid rotation is studied on the transport by homogeneous turbulence of a passive scalar with vertical mean scalar gradient. Connection with one-particle diffusion studied by Cambon et al. [C. Cambon, F.S. Godeferd, F. Nicolleau, J.C. Vassilicos, Turbulent diffusion in rapidly rotating turbulence with and without stable stratification, J. Fluid Mech. 499 (2004) 231-255] is discussed. The input of the initial anisotropy of the velocity field is then investigated in the axisymmetric case, using a general and systematic way to construct axisymmetric initial data: a classical expansion in terms of scalar spherical harmonics for the 3D spectral density of kinetic energy and a modified expansion for the polarization anisotropy. The scalar variance exhibits a quadratic evolution (∝t) for short times and a linear one (∝t) for larger times. The long-time behaviour looks similar to the classical 'Brownian' evolution but it has a very different origin: a linear impact of dispersive inertial waves via phase-mixing instead of a nonlinearly-induced random walk. It is shown that this trend is not altered by the polarization anisotropy. The vertical scalar flux varies linearly with time for short times and tends to a plateau for larger times. To cite this article: A. El Bach et al., C. R. Mecanique 336 (2008).

  15. Transitive reasoning distorts induction in causal chains.

    Science.gov (United States)

    von Sydow, Momme; Hagmayer, York; Meder, Björn

    2016-04-01

    A probabilistic causal chain A→B→C may intuitively appear to be transitive: If A probabilistically causes B, and B probabilistically causes C, A probabilistically causes C. However, probabilistic causal relations can only guaranteed to be transitive if the so-called Markov condition holds. In two experiments, we examined how people make probabilistic judgments about indirect relationships A→C in causal chains A→B→C that violate the Markov condition. We hypothesized that participants would make transitive inferences in accordance with the Markov condition although they were presented with counterevidence showing intransitive data. For instance, participants were successively presented with data entailing positive dependencies A→B and B→C. At the same time, the data entailed that A and C were statistically independent. The results of two experiments show that transitive reasoning via a mediating event B influenced and distorted the induction of the indirect relation between A and C. Participants' judgments were affected by an interaction of transitive, causal-model-based inferences and the observed data. Our findings support the idea that people tend to chain individual causal relations into mental causal chains that obey the Markov condition and thus allow for transitive reasoning, even if the observed data entail that such inferences are not warranted.

  16. Compact fluorescent lamps, LED lamps and harmonic distortion

    Science.gov (United States)

    Franco, A. M. R.; Debatin, R. M.; Cotia, F. C. G.; Silva, M. V. M.; Ribeiro, R. S.; Zampilis, R. R. N.

    2015-01-01

    The aim of this paper is to evaluate the harmonic distortion in the current waveform of Compact Fluorescent Lamps (CFL) and Lamps Lighting Emitting Diode (LED). For this, we analysed the power factor, voltage waveform, current waveform, total harmonic distortion (THD) and active power consumed.

  17. Motivational Distortion on 16 PF Primaries by Male Felons.

    Science.gov (United States)

    Wallbrown, Fred H.; And Others

    1989-01-01

    Investigated motivational distortion using the 16 Personality Factor Questionnaire (16 PF) for male (n=331) criminal offenders. Results indicated that ego-strength, free-floating anxiety, ability to bind anxiety, boldness, dominance, emotional sensitivity and suspiciousness contributed most to the motivational distortion scale predictions.…

  18. Cognitive Distortion and Psychological Distress in Chronic Low Back Pain.

    Science.gov (United States)

    Smith, Timothy W.; And Others

    1986-01-01

    Indicated that cognitive distortion was associated with high scores on the Minnesota Multiophasic Personality Inventory (MMPH) Depression (D), Psychasthenia (Pt), and Schizophrenia (Sc) scales, but not the Hypochondriasis (Hs) and Hysteria (Hy) scales. Cognitive distortion is likely to be an important factor in general distress but not in…

  19. Cognitive Distortion in Rheumatoid Arthritis: Relation to Depression and Disability.

    Science.gov (United States)

    Smith, Timothy W.; And Others

    1988-01-01

    Examined the relation between cognitive distortion, as measured by the Cognitive Error Questionnaire, and both self-reported and interview-rated depression and disability in 92 rheumatoid arthritis (RA) patients. Found cognitive distortion significantly associated with depression, and also related to physical disability. Discusses the results,…

  20. The Relationship between Depression, Irrational Beliefs, and Cognitive Distortions.

    Science.gov (United States)

    Chan, Florentius

    Studies have shown that depressed people have a significantly higher number of irrational beliefs and cognitive distortions than nondepressed people. The purpose of this study was to identify the causal relationship among depression, irrational beliefs, and cognitive distortions through the use of cross-lagged panel correlational analysis. On two…

  1. Cognitive Distortions, Coping Behavior, and Depression in College Students.

    Science.gov (United States)

    Warren, Nancy J.; And Others

    1982-01-01

    This study explored the relationship of cognitive distortions and coping strategies to depression in college students. A measure of cognitive distortions (the Interpretation Inventory) and a measure of strategies for coping with depression (the Active Checklist) were developed and used for this study. Results are discussed. (CJ)

  2. Perceptual distortion measure for edgelike artifacts in image sequences

    Science.gov (United States)

    Yeh, Edmund M.; Kokaram, Anil C.; Kingsbury, Nick G.

    1998-07-01

    This paper presents an objective perceptual distortion measure quantifying the visibility of edge-like blocking artifacts in coded image sequences resulting from popular transform coding techniques. The prime motivation for this work is the awareness that properties of the human visual system should be central to the design and evaluation of image coding algorithms. The perceptual metric is the output of a visual model incorporating both the spatial and temporal characteristics of the visual system. Parameters of the model are based on results from a number of visual experiments in which sensitivities to simulated blocking artifacts were measured under various spatio-temporal background conditions. The visual model takes a pair of original and distorted sequences as inputs. Distortions are calculated along the vertical and horizontal directions. Visibility dependencies on spatial, temporal and motion activities of the background are incorporated using linear filtering and motion estimation. Pixel-based distortions are combined over local spatial and temporal regions to generate an overall distortion measure for each orientation. The final model output is the sum of the vertical and horizontal distortion measures. The model was applied to coded image sequences and the resulting distortion measures were compared to outcomes of subjective ranking tests. Results indicate that the perceptual distortion measure agrees well with human evaluation.

  3. Distortion of Probability and Outcome Information in Risky Decisions

    Science.gov (United States)

    DeKay, Michael L.; Patino-Echeverri, Dalia; Fischbeck, Paul S.

    2009-01-01

    Substantial evidence indicates that information is distorted during decision making, but very few studies have assessed the distortion of probability and outcome information in risky decisions. In two studies involving six binary decisions (e.g., banning blood donations from people who have visited England, because of "mad cow disease"),…

  4. Distortion Mechanisms During Carburizing and Quenching in a Transmission Shaft

    Science.gov (United States)

    Tewary, Ujjal; Mohapatra, Goutam; Sahay, Satyam S.

    2017-10-01

    Distortion control during industrial carburizing and quenching operation of precision transmission components is of utmost importance due to their direct impact on performance, such as efficiency, noise and vibrations. The importance of controlling various heat treatment process parameters for mitigating distortion is well accepted, but their specific influence on mechanisms is less understood. In the present work, an integrated finite element-based model is used to simulate gas carburizing and quenching operation on a typical transmission shaft. Investigation is carried out on the effect of raw materials, carburizing and quenching process parameters to predict, analyze and minimize distortion. The effect of phase transformation and generation of thermal strain during heating and cooling stage of heat treatment is investigated, and the mechanisms of bending, diameter and length distortion of a shaft are analyzed. The displacive nature of transformation of bainite at higher temperature with its inherent large shear component of deformation was identified to be responsible for bending distortion in a shaft. Bainitic transformation, martensitic transformation and thermal strains developed during quenching cause volume expansion which leads to diameter expansion and lesser length shrinkage. Finally, bending distortion of a shaft and bore distortion of a gear are contrasted, both in terms of mechanisms and distortion control strategies.

  5. Improved neural network modeling of inverse lens distortion

    CSIR Research Space (South Africa)

    De Villiers, JP

    2011-04-01

    Full Text Available Inverse lens distortion modelling allows one to find the pixel in a distorted image which corresponds to a known point in object space, such as may be produced by a RADAR. This paper extends recent work using neural networks as a compromise between...

  6. Floral bud distortion in soybean and incidence in Central India ...

    African Journals Online (AJOL)

    Floral bud distortion in soybean and incidence in Central India. V Jadhav Pravin, SS Mane, RS Nandanwar, PB Kale, MS Dudhare, MP Moharil, RG Dani. Abstract. We describe a peculiar and often harmful budding disorder in soybean, leading to huge yield loss in India. To determine the prevalence of floral distortion in ...

  7. Computing Welding Distortion: Comparison of Different Industrially Applicable Methods

    NARCIS (Netherlands)

    Tikhomirov, D.; Rietman, Bert; Kose, K.; Makkink, M.

    2005-01-01

    Welding distortion is one of the major concerns of the industrial joining practice. In order to obtain optimal welding parameters many experiments have to be carried out. Numerical simulation enables a virtual examination of the welding distortion without performing expensive experiments. In this

  8. High-order harmonic generation from eld-distorted orbitals

    DEFF Research Database (Denmark)

    Spiewanowski, Maciek; Etches, Adam; Madsen, Lars Bojer

    We investigate the eect on high-order harmonic generation of the distortion of molecular orbitals by the driving laser eld. Calculations for high-order harmonic generation including orbital distortion are performed for N2 (high polarizability). Our results allow us to suggest that field...... of the minimum in the high-order harmonic spectra. This is in agreement with experiment....

  9. Analysis and control of harmonic distortions on electrical distribution ...

    African Journals Online (AJOL)

    ... peak factor and harmonic distortions of the alternating or sinusoidal wave forms. The consequences of harmonic distortions of transmitted electrical energy might be damage of con-densers, untimely release of circuit breakers, resonance in the networks, warming of transformers and over heat-ing of electrical appliances.

  10. Segregation distortion in F2 and doubled haploid populations of ...

    Indian Academy of Sciences (India)

    Yamagishi M., Takeuchi Y., Tanaka I., Kono I., Murai K. and Yano M. 2010. Segregation distortion in F2 and doubled haploid populations of temperate japonica rice. J. Genet. 89, 237–241] fertility is caused by S gene, resulting in the distortion of.

  11. An investigation of the open-loop amplification of Reynolds number dependent processes by wave distortion

    Science.gov (United States)

    Purdy, K. R.; Ventrice, M. B.; Fang, J.

    1972-01-01

    Analytical and experimental studies were initiated to determine if the response of a constant temperature hot wire anemometer to acoustic oscillations could serve as an analog to the response of the drop vaporization burning rate process to acoustic oscillations, and, perhaps, also as an analog to any Reynolds number dependent process. The motivation behind this study was a recent analytical study which showed that distorted acoustic oscillations could amplify the open-loop response of vaporization limited combustion. This type of amplification may be the cause of unstable combustion in liquid propellant rocket engines. The analytical results obtained for the constant temperature anemometer are similar in nature to those previously obtained for vaporization limited combustion and indicate that the response is dependent on the amount and type of distortion as well as other factors, such as sound pressure level, Mach number and hot wire temperature. Preliminary results indicate qualitative agreement between theory and experiment.

  12. A plasticity model with yield surface distortion for non proportional loading

    CERN Document Server

    François, Marc Louis Maurice

    2010-01-01

    In order to enhance the modeling of metallic materials behavior in non proportional loadings, a modification of the classical elastic-plastic models including distortion of the yield surface is proposed. The new yield criterion uses the same norm as in the classical von Mises based criteria, and a "distorted stress" Sd replacing the usual stress deviator S. The obtained yield surface is then ?egg-shaped? similar to those experimentally observed and depends on only one new material parameter. The theory is built in such a way as to recover the classical one for proportional loading. An identification procedure is proposed to obtain the material parameters. Simulations and experiments are compared for a 2024 T4 aluminum alloy for both proportional and nonproportional tension-torsion loading paths.

  13. Prediction of process induced shape distortions and residual stresses in large fibre reinforced composite laminates

    DEFF Research Database (Denmark)

    Nielsen, Michael Wenani

    The present thesis is devoted to numerical modelling of thermomechanical phenomena occurring during curing in the manufacture of large fibre reinforced polymer matrix composites with thick laminate sections using vacuum assisted resin transfer moulding (VARTM). The main application of interest...... in this work is modelling manufacturing induced shape distortions and residual stresses in commercial wind turbine composite blades. Key mechanisms known to contribute to shape distortions and residual stress build-up are reviewed and the underlying theories used to model these mechanisms are presented......) model in ABAQUS, different constitutive modelling approaches are investigated, including a cure hardening instantaneous linear elastic (CHILE) approach, a viscoelastic approach and a path-dependent approach. The latter is a limiting case of viscoelasticity. These approaches are investigated with regards...

  14. Cognitive distortions in obese patients with or without eating disorders.

    Science.gov (United States)

    Volery, M; Carrard, I; Rouget, P; Archinard, M; Golay, A

    2006-12-01

    In the normal weight population, cognitive distortions are more often found in people with eating disorders such as anorexia and bulimia than in a control population. With these cognitive distortions, weight and body image become central elements in self-esteem. This exploratory study investigated cognitive distortions in obese patients suffering from binge eating disorder or not. The hypothesis was that the patients suffering from binge eating disorder would have more cognitive distortions. Twenty-nine obese women (11 without and 18 with binge eating disorder) and 13 non-obese female controls were selected. To evaluate the cognitive distortions, subjects completed the Mizes Anorectic Cognitions-Revised (MAC-R) questionnaire. Contrary to our hypothesis, we found no difference in evidence between the two obese groups with or without eating disorders. Possible perspectives for treatment are discussed.

  15. Rapid Data Assimilation in the Indoor Environment: theory and examples from real-time interpretation of indoor plumes of airborne chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Gadgil, Ashok; Sohn, Michael; Sreedharan, Priya

    2008-09-01

    Releases of acutely toxic airborne contaminants in or near a building can lead to significant human exposures unless prompt response measures are identified and implemented. Commonly, possible responses include conflicting strategies, such as shutting the ventilation system off versus running it in a purge (100percent outside air) mode, or having occupants evacuate versus sheltering in place. The right choice depends in part on quickly identifying the source locations, the amounts released, and the likely future dispersion routes of the pollutants. This paper summarizes recent developments to provide such estimates in real time using an approach called Bayesian Monte Carlo updating. This approach rapidly interprets measurements of airborne pollutant concentrations from multiple sensors placed in the building and computes best estimates and uncertainties of the release conditions. The algorithm is fast, capable of continuously updating the estimates as measurements stream in from sensors. The approach is employed, as illustration, to conduct two specific investigations under different situations.

  16. Rapid Data Assimilation in the Indoor Environment: Theory and Examples from Real-Time Interpretation of Indoor Plumes of Airborne Chemical

    Energy Technology Data Exchange (ETDEWEB)

    Gadgil, Ashok; Gadgil, Ashok; Sohn, Michael; Sreedharan, Priya

    2007-08-01

    Releases of acutely toxic airborne contaminants in or near a building can lead to significant human exposures unless prompt response measures are identified and implemented. Possible responses include conflicting options, such as shutting the ventilation system off versus running it in a purge (100 percent outside air) mode, or having occupants evacuate versus sheltering in place. The right choice depends in part on quickly identifying the source location, the amount released, and the likely future dispersion of the pollutant. This paper summarizes recent developments to provide such estimates in real time using an approach called Bayesian Monte Carlo updating. This approach rapidly interprets measurements of airborne pollutant concentrations from multiple sensors placed in the building, and computes best estimates and uncertainties of the release conditions. The algorithm is fast, and can continuously update the estimates as measurements stream in from sensors. As an illustration, two specific applications of the approach are described.

  17. Prussian phenomenon and its historical distortion

    Directory of Open Access Journals (Sweden)

    Oleg Y. Plenkov

    2016-03-01

    Full Text Available The article deals with the phenomenon of Prussia. Once, Prussia had been the largest continental Protestant state in Europe. The main issue of this phenomenon is that upon the tragic events of the World War II Prussian history and heritage had been considerably distorted, in order to compensate somehow for the dreadful casualties suffered by the victorious powers. The common European misconception implied that Prussia had been the bulwark of militarism, and therefore had to bear all the responsibility for the atrocities of war. Unfortunately, the majority of modern German historians share such misinterpretation of Prussian heritage in order to please false political correctness, perhaps, as an act of contrition for National Socialism and its crimes. However, the Prussian tradition and history go far beyond this militarism, and this article explains what ways. The authors believe that there should not be any prejudices and biases, that any subject should be examined sine ira et studio. Moreover, given that it is possible to characterize the Great French Revolution as a juristic one, and the Great October revolution – as a social one, the Prussian revolution “from above”, led by the first representatives of the Hohenzollern family, may be well considered as a pedagogical revolution. This revolution did bring definitely positive changes; they are surveyed in the article. The French Revolution has not eliminated the covetousness of the bourgeoisie after 1789; despotism of the authorities and people’s passiveness similarly have remained unaltered in Russia after 1917. On the contrary, Federal Republic of Germany of nowadays, distinctive for its law, order and effective responsible government is unthinkable without Prussian heritage.

  18. Subjective duration distortions mirror neural repetition suppression.

    Directory of Open Access Journals (Sweden)

    Vani Pariyadath

    Full Text Available Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression.Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli followed by a line presented at a different orientation (oddball stimulus. We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context--that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials.Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

  19. An X-linked sex ratio distorter in Drosophila simulans that kills or incapacitates both noncarrier sperm and sons.

    Science.gov (United States)

    Rice, William R

    2014-07-31

    Genomic conflict occurs when a genomic component gains a reproductive advantage at the expense of the organism as a whole. X-linked segregation distorters kill or incapacitate Y-bearing sperm, thereby gaining a transmission advantage but also reducing male fertility and generating a female-biased sex ratio. When some damaged, Y-bearing sperm survive and fertilize eggs, then the segregation distortion phenotype could be expanded by harming or killing sons in the next generation. X-linked son-killers are predicted by theory to be favored by natural selection and evolve when brothers and sisters compete for shared limiting resources and/or when brothers reduce the inclusive fitness of their sisters via sib-mating-a phenomenon called SA-zygotic drive. Here I develop and use a process-of-elimination screen to show that an unclassified X-linked sex ratio distorter (skew) in Drosophila simulans kills or incapacitates noncarrier sperm and also kills a substantial proportion of sons, i.e., it has both a segregation distortion and a SA-zygotic drive phenotype. There are three unique X-linked segregation distorters known to occur in D. simulans named Winters, Durham, and Paris. Autosomal-dominant suppressors of Winters (Nmy) and Durham (Tmy) failed to suppress skew. A Y-linked suppressor of Paris, however, did suppress skew, and a recombination test failed to detect recombinants between these two sex ratio distorters, indicating that they are tightly linked and plausibly identical or allelic. Son-killing may be an important yet unrecognized component of other X-linked segregation distorters. Copyright © 2014 Rice.

  20. Bilateral Symmetry of Distortions of Tactile Size Perception.

    Science.gov (United States)

    Longo, Matthew R; Ghosh, Arko; Yahya, Tasneem

    2015-01-01

    The perceived distance between touches on the limbs is generally bigger for distances oriented across the width of the limb than for distances oriented along the length of the limb. The present study aimed to investigate the coherence of such distortions of tactile size perception across different skin surfaces. We investigated distortions of tactile size perception on the dorsal and palmar surfaces of both the left and right hands as well as the forehead. Participants judged which of two tactile distances felt larger. One distance was aligned with the proximodistal axis (along the body), the other with the mediolateral axis (across the body). Clear distortions were found on all five skin surfaces, with stimuli oriented across the width of the body being perceived as farther apart than those oriented along the length of the body. Consistent with previous results, distortions were smaller on the palmar than on the dorsal hand surface. Distortion on the forehead was intermediate between the dorsal and palmar surfaces. There were clear correlations between distortion on the left and right hands, for both the dorsal and palmar skin surfaces. In contrast, within each hand, there was no significant correlation between the two skin surfaces. Distortion on the forehead was not significantly correlated with that on any of the other skin surfaces. These results provide evidence for bilaterally symmetric representations underlying tactile size perception. © The Author(s) 2015.

  1. Die Casting Part Distortion: Prediction and Attenuation

    Energy Technology Data Exchange (ETDEWEB)

    Dr, R. Allen Miller

    2002-02-12

    The goal of this research was to predict the part deformation and residual stresses after ejection from the die and cooling to room temperature. A finite element model was built to achieve this goal and several modeling techniques were investigated throughout this research. Die-casting is a very complex process and the researchers are faced with a large number of hard to solve physical problems when modeling the process. Several assumptions are made in our simulation model. The first significant assumption is the instantaneous cavity filling. This means that the cavity filling stage is not considered in our model. Considering the cavity filling stage increases the modeling complexity as a result of different flow patterns. expected in the shot sleeve, gate, runner and different cavity features. The flow of gas from the cavity through the vents is another problem that is ignored in our model as a result of this assumption. Our second assumption is that the cast metal has uniform temperature distribution inside the cavity, at the starting point of simulation. This temperature is assumed to be over liquidus limit, i.e. the solid fraction is 0.0% of the cast metal. The third assumption is due to ABAQUS (commercial software used in this research) limitations. ABAQUS cannot deal with multi-phase models; therefore we use solid elements to define the casting instead of multi-phase (liquid/solid) elements. Liquid elements can carry the hydrostatic pressure from the shot sleeve and apply it on the cavity surfaces, while the solid elements do not have this capability. To compensate for this assumption we add the cavity pressure as a boundary condition and apply it on the cavity surface separately from the part. Another issue with this assumption is that, liquid casting can follow the cavity shape when it distorts. With the use of solid elements to represent the casting during its liquid state, it loses this capability to follow the cavity. Several techniques were tested to

  2. Computing sextic centrifugal distortion constants by DFT: A benchmark analysis on halogenated compounds

    Science.gov (United States)

    Pietropolli Charmet, Andrea; Stoppa, Paolo; Tasinato, Nicola; Giorgianni, Santi

    2017-05-01

    This work presents a benchmark study on the calculation of the sextic centrifugal distortion constants employing cubic force fields computed by means of density functional theory (DFT). For a set of semi-rigid halogenated organic compounds several functionals (B2PLYP, B3LYP, B3PW91, M06, M06-2X, O3LYP, X3LYP, ωB97XD, CAM-B3LYP, LC-ωPBE, PBE0, B97-1 and B97-D) were used for computing the sextic centrifugal distortion constants. The effects related to the size of basis sets and the performances of hybrid approaches, where the harmonic data obtained at higher level of electronic correlation are coupled with cubic force constants yielded by DFT functionals, are presented and discussed. The predicted values were compared to both the available data published in the literature and those obtained by calculations carried out at increasing level of electronic correlation: Hartree-Fock Self Consistent Field (HF-SCF), second order Møller-Plesset perturbation theory (MP2), and coupled-cluster single and double (CCSD) level of theory. Different hybrid approaches, having the cubic force field computed at DFT level of theory coupled to harmonic data computed at increasing level of electronic correlation (up to CCSD level of theory augmented by a perturbational estimate of the effects of connected triple excitations, CCSD(T)) were considered. The obtained results demonstrate that they can represent reliable and computationally affordable methods to predict sextic centrifugal terms with an accuracy almost comparable to that yielded by the more expensive anharmonic force fields fully computed at MP2 and CCSD levels of theory. In view of their reduced computational cost, these hybrid approaches pave the route to the study of more complex systems.

  3. Distortion correction of EPI data using multimodal nonrigid registration with an anisotropic regularization.

    Science.gov (United States)

    Glodeck, Daniel; Hesser, Jürgen; Zheng, Lei

    2016-02-01

    In this paper, a novel strategy for correcting both geometric and image intensity distortions of echo-planar imaging (EPI) MRI data is presented. To deal with small local distortions caused by rapid changes of the magnetic field, an improved multimodal registration framework using normalized mutual information (NMI) in combination with a multi-scale technique is presented to estimate a dense displacement field. To ensure the robustness of this high dimensional ill-posed inverse problem, a novel anisotropic regularization functional is used. In order to quantify geometric distortions, a new quality measure, called standardized contour distance (SCD), is introduced. It uses the outer structure shape (OSS) information as basis for the evaluation. The new registration method was evaluated with one monomodal phantom data set and two multimodal human brain data sets (BrainSuite trainings data, SPM Subject data). By comparing with recent and efficient techniques of the state of the art, in the monomodal case, the new approach achieves results comparable to the sum of squared differences as data term. In the multimodal cases, our new registration strategy improves the mean of the SCD from 0.96±0.11 to 0.60±0.13 in case of the SPM Subject data and from 0.92±0.07 to 0.78±0.11 in case of the BrainSuite trainings data. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Retrospective perceptual distortion of position representation does not lead to delayed localization.

    Science.gov (United States)

    Au, Ricky K C; Ono, Fuminori; Watanabe, Katsumi

    2013-01-01

    Previous studies have reported retrospective influences of visual events that occur after target events. In the attentional attraction effect, a position cue presented after a target stimulus distorts the target's position towards that of the cue. The present study explored the temporal relationship between stimulus presentation and reaction time (RT) in this effect in two experiments. Participants performed a speeded localization task on two vertical lines, the positions of which were to be distorted by an additional attentional cue. No significant difference in RTs was found between the conditions with simultaneous and delayed cues. RTRT was modulated by the perceived (rather than physical) alignment of the lines. In Experiment 2, we manipulated the strength of attentional capture by modulating the color relevance of the cue to the target. Trials with cues producing stronger attentional capture (with cues of a different color from the targets) were found to induce apparently stronger distortion effects. This result favors the notion that the observed repulsion and attraction effects are driven by attentional mechanisms. Overall, the results imply that the attentional shift induced by the cue might occur rapidly and complete before the establishment of conscious location representation of the cue and the target without affecting overall response time.

  5. METHOD OF RADIOMETRIC DISTORTION CORRECTION OF MULTISPECTRAL DATA FOR THE EARTH REMOTE SENSING

    Directory of Open Access Journals (Sweden)

    A. N. Grigoriev

    2015-07-01

    Full Text Available The paper deals with technologies of ground secondary processing of heterogeneous multispectral data. The factors of heterogeneous data include uneven illumination of objects on the Earth surface caused by different properties of the relief. A procedure for the image restoration of spectral channels by means of terrain distortion compensation is developed. The object matter of this paper is to improve the quality of the results during image restoration of areas with large and medium landforms. Methods. Researches are based on the elements of the digital image processing theory, statistical processing of the observation results and the theory of multi-dimensional arrays. Main Results. The author has introduced operations on multidimensional arrays: concatenation and elementwise division. Extended model description for input data about the area is given. The model contains all necessary data for image restoration. Correction method for multispectral data radiometric distortions of the Earth remote sensing has been developed. The method consists of two phases: construction of empirical dependences for spectral reflectance on the relief properties and restoration of spectral images according to semiempirical data. Practical Relevance. Research novelty lies in developme nt of the application theory of multidimensional arrays with respect to the processing of multispectral data, together with data on the topography and terrain objects. The results are usable for development of radiometric data correction tools. Processing is performed on the basis of a digital terrain model without carrying out ground works connected with research of the objects reflective properties.

  6. Lattice Distortion in In3SbTe2 Phase Change Material with Substitutional Bi.

    Science.gov (United States)

    Choi, Minho; Choi, Heechae; Kim, Seungchul; Ahn, Jinho; Kim, Yong Tae

    2015-08-11

    Sb atoms in In3SbTe2 (IST) are partially substituted by 3.2-5.5 at.% of Bi atoms. As a result, the NaCl crystal structure of IST is slightly distorted. The distorted inter-planar angles observed with fast Fourier transformation of the lattice images are within the maximum range of interplanar angles calculated by density functional theory. When the Bi content is increased, the crystallization temperature becomes relatively lower than that of IST, the activation energy decreases from 5.29 to 2.61 eV, and the specific heat and melting point are obviously reduced. Consequently, phase change random access memory (PRAM) fabricated with Bi-doped IST (Bi-IST) can operate with lower power consumption than pure IST PRAM. The set and reset speeds of PRAM cells fabricated with Bi-IST are both 100 ns with 5.5 at.% Bi, which are obviously faster than the switching speeds of PRAM cells fabricated with IST and Ge2Sb2Te5 (GST). These experimental results reveal that the switching speed is closely related with the thermal properties of the distorted lattice structure.

  7. A finite element framework for distortion gradient plasticity with applications to bending of thin foils

    DEFF Research Database (Denmark)

    Martínez Pañeda, Emilio; Niordson, Christian Frithiof; Bardella, Lorenzo

    2016-01-01

    by Gurtin (2004) through the prescription of a free energy dependent on Nye’s dislocation density tensor. The proposed numerical scheme is developed by following and extending the mathematical principles established by Fleck and Willis (2009). The modeling of thin metallic foils under bending reveals......A novel general purpose Finite Element framework is presented to study small-scale metal plasticity. A distinct feature of the adopted distortion gradient plasticity formulation, with respect to strain gradient plasticity theories, is the constitutive inclusion of the plastic spin, as proposed...

  8. A finite element framework for distortion gradient plasticity with applications to bending of thin foils

    DEFF Research Database (Denmark)

    Martínez Pañeda, Emilio; Niordson, Christian Frithiof; Bardella, Lorenzo

    2016-01-01

    A novel general purpose Finite Element framework is presented to study small-scale metal plasticity. A distinct feature of the adopted distortion gradient plasticity formulation, with respect to strain gradient plasticity theories, is the constitutive inclusion of the plastic spin, as proposed...... by Gurtin (2004) through the prescription of a free energy dependent on Nye’s dislocation density tensor. The proposed numerical scheme is developed by following and extending the mathematical principles established by Fleck and Willis (2009). The modeling of thin metallic foils under bending reveals...

  9. On the application of binary correction factors in lattice distortion calculations for methane clathrate hydrates

    Science.gov (United States)

    Lasich, Matthew; Mohammadi, Amir H.; Bolton, Kim; Vrabec, Jadran; Ramjugernath, Deresh

    2014-03-01

    The lattice distortion theory of Zele and co-workers is an attractive method for amending calculated phase equilibria of clathrate hydrates, since only two molecular computations are required. The perturbation energy between the empty and loaded clathrate hydrate lattice is the quantity of interest. The effect of binary correction factors applied to the Lorentz and Berthelot combining rules for the intermolecular interaction between gas and water particles is investigated. There are clear trends for the perturbation energy and lattice constant in terms of the binary correction factors, although there is significant sensitivity to the force field parameterization of the gas species.

  10. Pulse Distortion in Saturated Fiber Optical Parametric Chirped Pulse Amplification

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Da Ros, Francesco; Rottwitt, Karsten

    2012-01-01

    Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation....

  11. Correcting the Chromatic Aberration in Barrel Distortion of Endoscopic Images

    Directory of Open Access Journals (Sweden)

    Y. M. Harry Ng

    2003-04-01

    Full Text Available Modern endoscopes offer physicians a wide-angle field of view (FOV for minimally invasive therapies. However, the high level of barrel distortion may prevent accurate perception of image. Fortunately, this kind of distortion may be corrected by digital image processing. In this paper we investigate the chromatic aberrations in the barrel distortion of endoscopic images. In the past, chromatic aberration in endoscopes is corrected by achromatic lenses or active lens control. In contrast, we take a computational approach by modifying the concept of image warping and the existing barrel distortion correction algorithm to tackle the chromatic aberration problem. In addition, an error function for the determination of the level of centroid coincidence is proposed. Simulation and experimental results confirm the effectiveness of our method.

  12. Optical Distortion Evaluation in Large Area Windows using Interferometry

    Science.gov (United States)

    Youngquist, Robert C.; Skow, Miles; Nurge, Mark A.

    2015-01-01

    It is important that imagery seen through large area windows, such as those used on space vehicles, not be substantially distorted. Many approaches are described in the literature for measuring the distortion of an optical window, but most suffer from either poor resolution or processing difficulties. In this paper a new definition of distortion is presented, allowing accurate measurement using an optical interferometer. This new definition is shown to be equivalent to the definitions provided by the military and the standards organizations. In order to determine the advantages and disadvantages of this new approach the distortion of an acrylic window is measured using three different methods; image comparison, Moiré interferometry, and phase-shifting interferometry.

  13. Mitigation of Engine Inlet Distortion Through Adjoint-Based Design

    Science.gov (United States)

    Ordaz, Irian; Rallabhandi, Sriram; Nielsen, Eric J.; Diskin, Boris

    2017-01-01

    The adjoint-based design capability in FUN3D is extended to allow efficient gradient- based optimization and design of concepts with highly integrated aero-propulsive systems. A circumferential distortion calculation, along with the derivatives needed to perform adjoint-based design, have been implemented in FUN3D. This newly implemented distortion calculation can be used not only for design but also to drive the existing mesh adaptation process and reduce the error associated with the fan distortion calculation. The design capability is demonstrated by the shape optimization of an in-house aircraft concept equipped with an aft fuselage propulsor. The optimization objective is the minimization of flow distortion at the aerodynamic interface plane of this aft fuselage propulsor.

  14. Effects of skin elasticity on bite mark distortion.

    Science.gov (United States)

    Lewis, Cheri; Marroquin, Leonor A

    2015-12-01

    Bite marks have been reported to have an evidentiary value similar to fingerprints. We believed bite mark distortion would impact the accuracy and reliability of bite mark interpretation. Inked denture-stamps were substituted for actual bite marks and were placed onto 40 participating volunteers' shoulders. Four changes in arm position were photographed using an ABFO #2 reference scale. The measurements of individual tooth widths and intercanine distances in each position were compared. The maximum tooth width distortion observed was 53.8%, whereas the maximum intercanine distance distortion was 41.9%. Distortion was found to increase with age and weight and was non-uniform across a dental arch. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Computational Prediction of Local Distorted Flow in Turbocharger

    Science.gov (United States)

    Yao, J.; Yao, Y. F.; Manson, P. J.; Zhang, T.; Heyes, F. J. G.; Roach, P. E.

    This paper presents numerical study by performing three-dimensional Navier-Stokes solution for mixture gas flow in a typical industrial turbocharger configuration. The primary focuses are the flow distortions and behaviours in the proximity of the nozzle vanes. Numerical predictions reveal local flow distortions, shown by a considerable total pressure drop of about 7.5%. The possible reason for this is probably due to the influence of the upstream guide vane wake flow. At both design and off-design conditions considered in this study, the flow near the nozzle vanes has noticeable inhomogeneous in the circumferential direction. However, both local flow distortions and inhomogeneous in annulus are gradually reduced and the flow recovers to near uniform at the nozzle exit plane. Thus the predicted flow distortions have negligible effects on downstream turbine blades.

  16. Estimates of Atmospheric Distortion Number for Nonlinear Refraction

    National Research Council Canada - National Science Library

    Roadcap, J. R; McNicholl, P. J; Beland, R. R; Jumper, G. Y

    2007-01-01

    A characteristic nondimensional distortion number Nd was derived in the 1970s that allows inference of the degree of nonlinear refraction or thermal blooming associated with an atmospheric laser path...

  17. An Accurate Projector Calibration Method Based on Polynomial Distortion Representation

    OpenAIRE

    Liu, Miao; Sun, Changku; Huang, Shujun; Zhang, Zonghua

    2015-01-01

    In structure light measurement systems or 3D printing systems, the errors caused by optical distortion of a digital projector always affect the precision performance and cannot be ignored. Existing methods to calibrate the projection distortion rely on calibration plate and photogrammetry, so the calibration performance is largely affected by the quality of the plate and the imaging system. This paper proposes a new projector calibration approach that makes use of photodiodes to directly dete...

  18. Factors associated with body image distortion in Korean adolescents

    OpenAIRE

    Hyun,Mi-Yeul; Jung, Young-Eun; Kim, Moon-Doo; Kwak, Young-Sook; Hong, Sung-Chul; Bahk, Won-Myong; Yoon, Bo-Hyun; Yoon, Hye Won; Yoo, Bora

    2014-01-01

    Purpose Body image incorporates cognitive and affective components as well as behaviors related to own body perception. This study evaluated the occurrence of body image distortion and its correlates in Korean adolescents. Methods In a school-based cross-sectional survey, a total of 2,117 adolescents were recruited. They filled out self-completing questionnaires on body image distortion, eating attitudes, and behaviors (Eating Attitude Test-26) and related factors. Results Body image distorti...

  19. Distortion mechanisms in varactor diode-tuned microwave filters

    OpenAIRE

    Carey-Smith, BE; Warr, PA

    2006-01-01

    This paper examines the broadband distortion behavior in flexible filters employing varactor-diode tuning elements. Series- and parallel-resonant varactor-loaded transmission-lines, both commonly used in bandpass and bandstop microwave filters, are analyzed. Nonlinear Volterra-series analysis is employed to determine the second- and third-order distortion ratios dependent on the frequencies of the incident signals. It is shown that in a bandpass filter (employing parallel tuned resonators), m...

  20. The relationship between cognitive distortions and forgiveness in romantic relationships

    OpenAIRE

    Gökçen Aydın; Nasibe Kandemir Özdinç; Meral Aksu

    2015-01-01

    The purpose of the present study was to find out the relationship between cognitive distortions and forgiveness in romantic relationships of college students. The sample of the study was 340 college students who have a romantic relationship at a state university in Turkey. The purposeful sampling method was carried out in this correlational study. In order to collect data, three instruments were utilized: Interpersonal Cognitive Distortions Scale (ICDS), Heartland Forgiveness Scale and Demogr...

  1. Nonlinear distortion in wireless systems modeling and simulation with Matlab

    CERN Document Server

    Gharaibeh, Khaled M

    2011-01-01

    This book covers the principles of modeling and simulation of nonlinear distortion in wireless communication systems with MATLAB simulations and techniques In this book, the author describes the principles of modeling and simulation of nonlinear distortion in single and multichannel wireless communication systems using both deterministic and stochastic signals. Models and simulation methods of nonlinear amplifiers explain in detail how to analyze and evaluate the performance of data communication links under nonlinear amplification. The book addresses the analysis of nonlinear systems

  2. Base Station Antenna Pattern Distortion in Practical Urban Deployment Scenarios

    DEFF Research Database (Denmark)

    Rodriguez Larrad, Ignacio; Nguyen, Huan Cong; Sørensen, Troels Bundgaard

    2014-01-01

    the intrinsic propagation mechanisms of the urban environment (far-field) can contribute to the distortion of the radiation pattern observed in a practical deployment scenario, especially when comparing it to the antenna pattern provided by the manufacturer and typically measured in free space. This paper......-field distortion has been evaluated by means of finite integration technique (FIT) simulations, while the far-field effects have been analyzed through intelligent ray tracing (IRT)....

  3. Parameterization of temperature and spectral distortions in future CMB experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pitrou, Cyril; Stebbins, Albert

    2014-10-15

    CMB spectral distortions are induced by Compton collisions with electrons. We review the various schemes to characterize the anisotropic CMB with a non-Planckian spectrum. We advocate using logarithmically averaged temperature moments as the preferred language to describe these spectral distortions, both for theoretical modeling and observations. Numerical modeling is simpler, the moments are frame-independent, and in terms of scattering the mode truncation is exact.

  4. Optical activity of chirally distorted nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Tepliakov, Nikita V.; Baimuratov, Anvar S.; Baranov, Alexander V.; Fedorov, Anatoly V. [Department of Optical Physics and Modern Natural Science, ITMO University, Saint Petersburg 197101 (Russian Federation); Rukhlenko, Ivan D., E-mail: rukhlenko.ivan@gmail.com [Department of Optical Physics and Modern Natural Science, ITMO University, Saint Petersburg 197101 (Russian Federation); Monash University, Clayton Campus, Victoria 3800 (Australia)

    2016-05-21

    We develop a general theory of optical activity of semiconductor nanocrystals whose chirality is induced by a small perturbation of their otherwise achiral electronic subsystems. The optical activity is described using the quantum-mechanical expressions for the rotatory strengths and dissymmetry factors introduced by Rosenfeld. We show that the rotatory strengths of optically active transitions are decomposed on electric dipole and magnetic dipole contributions, which correspond to the electric dipole and magnetic dipole transitions between the unperturbed quantum states. Remarkably, while the two kinds of rotatory strengths are of the same order of magnitude, the corresponding dissymmetry factors can differ by a factor of 10{sup 5}. By maximizing the dissymmetry of magnetic dipole absorption one can significantly enhance the enantioselectivity in the interaction of semiconductor nanocrystals with circularly polarized light. This feature may advance chiral and analytical methods, which will benefit biophysics, chemistry, and pharmaceutical science. The developed theory is illustrated by an example of intraband transitions inside a semiconductor nanocuboid, whose rotatory strengths and dissymmetry factors are calculated analytically.

  5. Correcting dynamic distortions in 7T echo planar imaging using a jittered echo time sequence

    Science.gov (United States)

    Dymerska, Barbara; Poser, Benedikt A.; Bogner, Wolfgang; Visser, Eelke; Eckstein, Korbinian; Cardoso, Pedro; Barth, Markus; Trattnig, Siegfried

    2015-01-01

    Purpose To develop a distortion correction method for echo planar imaging (EPI) that is able to measure dynamic changes in B0. Theory and Methods The approach we propose is based on single‐echo EPI with a jittering of the echo time between two values for alternate time points. Field maps are calculated between phase images from adjacent volumes and are used to remove distortion from corresponding magnitude images. The performance of our approach was optimized using an analytical model and by comparison with field maps from dual‐echo EPI. The method was tested in functional MRI experiments at 7T with motor tasks and compared with the conventional static approach. Results Unwarping using our method was accurate even for head rotations up to 8.2°, where the static approach introduced errors up to 8.2 mm. Jittering the echo time between 19 and 25 ms had no measurable effect on blood oxygenation level–dependent (BOLD) sensitivity. Our approach reduced the distortions in activated regions to distortion correction in the presence of motion. No reduction in BOLD sensitivity was observed. As such, it is suitable for application in a wide range of functional MRI experiments. Magn Reson Med 76:1388–1399, 2016. © 2015 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26584148

  6. Factors associated with body image distortion in Korean adolescents.

    Science.gov (United States)

    Hyun, Mi-Yeul; Jung, Young-Eun; Kim, Moon-Doo; Kwak, Young-Sook; Hong, Sung-Chul; Bahk, Won-Myong; Yoon, Bo-Hyun; Yoon, Hye Won; Yoo, Bora

    2014-01-01

    Body image incorporates cognitive and affective components as well as behaviors related to own body perception. This study evaluated the occurrence of body image distortion and its correlates in Korean adolescents. In a school-based cross-sectional survey, a total of 2,117 adolescents were recruited. They filled out self-completing questionnaires on body image distortion, eating attitudes, and behaviors (Eating Attitude Test-26) and related factors. Body image distortions were found in 51.8 percent of adolescents. Univariate analyses showed that boys and older adolescents had higher rates of body image distortion. In the multivariate analyses, body image distortion was associated with high risk for eating disorders (odds ratio [OR] =1.69; 95% confidence interval [CI] 1.11-2.58; P=0.015) and being over weight (OR =33.27; 95% CI 15.51-71.35; Pbody image distortion is relatively common in Korean adolescents, which has implications for adolescents at risk of developing eating disorders.

  7. Remote sensing image compression assessment based on multilevel distortions

    Science.gov (United States)

    Jiang, Hongxu; Yang, Kai; Liu, Tingshan; Zhang, Yongfei

    2014-01-01

    The measurement of visual quality is of fundamental importance to remote sensing image compression, especially for image quality assessment and compression algorithm optimization. We exploit the distortion features of optical remote sensing image compression and propose a full-reference image quality metric based on multilevel distortions (MLD), which assesses image quality by calculating distortions of three levels (such as pixel-level, contexture-level, and content-level) between original images and compressed images. Based on this, a multiscale MLD (MMLD) algorithm is designed and it outperforms the other current methods in our testing. In order to validate the performance of our algorithm, a special remote sensing image compression distortion (RICD) database is constructed, involving 250 remote sensing images compressed with different algorithms and various distortions. Experimental results on RICD and Laboratory for Image and Video Engineering databases show that the proposed MMLD algorithm has better consistency with subjective perception values than current state-of-the-art methods in remote sensing image compression assessment, and the objective assessment results can show the distortion features and visual quality of compressed image well. It is suitable to be the evaluation criteria for optical remote sensing image compression.

  8. Economic choices reveal probability distortion in macaque monkeys.

    Science.gov (United States)

    Stauffer, William R; Lak, Armin; Bossaerts, Peter; Schultz, Wolfram

    2015-02-18

    Economic choices are largely determined by two principal elements, reward value (utility) and probability. Although nonlinear utility functions have been acknowledged for centuries, nonlinear probability weighting (probability distortion) was only recently recognized as a ubiquitous aspect of real-world choice behavior. Even when outcome probabilities are known and acknowledged, human decision makers often overweight low probability outcomes and underweight high probability outcomes. Whereas recent studies measured utility functions and their corresponding neural correlates in monkeys, it is not known whether monkeys distort probability in a manner similar to humans. Therefore, we investigated economic choices in macaque monkeys for evidence of probability distortion. We trained two monkeys to predict reward from probabilistic gambles with constant outcome values (0.5 ml or nothing). The probability of winning was conveyed using explicit visual cues (sector stimuli). Choices between the gambles revealed that the monkeys used the explicit probability information to make meaningful decisions. Using these cues, we measured probability distortion from choices between the gambles and safe rewards. Parametric modeling of the choices revealed classic probability weighting functions with inverted-S shape. Therefore, the animals overweighted low probability rewards and underweighted high probability rewards. Empirical investigation of the behavior verified that the choices were best explained by a combination of nonlinear value and nonlinear probability distortion. Together, these results suggest that probability distortion may reflect evolutionarily preserved neuronal processing. Copyright © 2015 Stauffer et al.

  9. Measurement of weldpiece distortion during pulsed laser welding using rapid laser profilometry

    OpenAIRE

    Gorkič, Aleš; Jezeršek, Matija; Možina, Janez; Diaci, Janez

    2015-01-01

    The present paper reports a new setup for acquisition of shape data for weldpieces during pulsed laser welding. The setup is based on illumination of the weldpiece surface by laser light, which is structured as multiple light planes, and acquisition of the image of the illuminated surface by a digital camera. The position of the optical system is fixed relative to the measured weldpiece. The acquired image is fed into a personal computer where it is processed to obtain the three-dimensional s...

  10. A Survey of Measurements and Measuring Techniques in Rapidly Distorted Compressible Turbulent Boundary Layers

    Science.gov (United States)

    1989-05-01

    direct heating of the wire for a. , 0.1 (Bonnet & Alziary de Roquefort 1980), and it appears to be reliable technique for setting the frequency...54: 1513-1524. Bonnet, J. P. and Alziary de Roquefort , T. (1980), Determination and optimization of frequency response of constant temperature hot

  11. Gambling-Related Distortions and Problem Gambling in Adolescents: A Model to Explain Mechanisms and Develop Interventions

    Directory of Open Access Journals (Sweden)

    Maria Anna Donati

    2018-01-01

    Full Text Available Although a number of gambling preventive initiatives have been realized with adolescents, many of them have been developed in absence of a clear and explicitly described theoretical model. The present work was aimed to analyze the adequacy of a model to explain gambling behavior referring to gambling-related cognitive distortions (Study 1, and to verify the effectiveness of a preventive intervention developed on the basis of this model (Study 2. Following dual-process theories on cognitive functioning, in Study 1 we tested a model in which mindware gap, i.e., susceptibility to the gambler’s fallacy, and contaminated mindware, i.e., superstitious thinking, were the antecedents of gambling-related cognitive distortions that, in turn, affect gambling frequency and problem gambling. Participants were 306 male adolescents (Mage = 17.2 years. A path analysis indicated that cognitive distortions have a mediating role in the relationship that links probabilistic reasoning fallacy and superstitious thinking with problem gambling. Following these findings, in Study 2 we developed a school-based intervention aimed to reduce gambling-related cognitive distortions acting on the above cited mindware problems. A pre- and post-test design – with a 6 months follow-up – was performed with 34 male adolescents (Mage = 16.8, randomly assigned to two groups (Training and No Training, and their baseline equivalence was verified. A Mixed 2 × 2 ANOVA attested a significant Time X Group interaction, indicating a significant reduction of the cognitive distortions from pre-test to post-test only in the Training group. The follow-up attested to the stability of the training effects and the reduction of gambling frequency over time. These findings suggest that prevention strategies should address mindware problems, which can be considered as predictors of gambling-related cognitive distortions.

  12. Gambling-Related Distortions and Problem Gambling in Adolescents: A Model to Explain Mechanisms and Develop Interventions

    OpenAIRE

    Maria Anna Donati; Francesca Chiesi; Adriana Iozzi; Antonella Manfredi; Fabrizio Fagni; Caterina Primi

    2018-01-01

    Although a number of gambling preventive initiatives have been realized with adolescents, many of them have been developed in absence of a clear and explicitly described theoretical model. The present work was aimed to analyze the adequacy of a model to explain gambling behavior referring to gambling-related cognitive distortions (Study 1), and to verify the effectiveness of a preventive intervention developed on the basis of this model (Study 2). Following dual-process theories on cognitive ...

  13. Treatment of Medial Tibial Stress Syndrome according to the Fascial Distortion Model: A Prospective Case Control Study

    OpenAIRE

    Schulze, Christoph; Finze, Susanne; Bader, Rainer; Lison, Andreas

    2014-01-01

    Medial tibial stress syndrome (MTSS) is a common problem among athletes and soldiers. There is no proven theory that could explain the pathophysiology of shin splints. The therapies described so far are time-consuming and involve a high risk of relapse. The method according to the fascial distortion model (FDM) addresses local changes in the area of the lower leg fascia. It is suited to reduce pain and functional impairments associated with this symptom complex by applying targeted manual tec...

  14. More flexibility in representing geometric distortion in astronomical images

    Science.gov (United States)

    Shupe, David L.; Laher, Russ R.; Storrie-Lombardi, Lisa; Surace, Jason; Grillmair, Carl; Levitan, David; Sesar, Branimir

    2012-09-01

    A number of popular software tools in the public domain are used by astronomers, professional and amateur alike, but some of the tools that have similar purposes cannot be easily interchanged, owing to the lack of a common standard. For the case of image distortion, SCAMP and SExtractor, available from Astromatic.net, perform astrometric calibration and source-object extraction on image data, and image-data geometric distortion is computed in celestial coordinates with polynomial coefficients stored in the FITS header with the PV i_j keywords. Another widely-used astrometric-calibration service, Astrometry.net, solves for distortion in pixel coordinates using the SIP convention that was introduced by the Spitzer Science Center. Up until now, due to the complexity of these distortion representations, it was very difficult to use the output of one of these packages as input to the other. New Python software, along with faster-computing C-language translations, have been developed at the Infrared Processing and Analysis Center (IPAC) to convert FITS-image headers from PV to SIP and vice versa. It is now possible to straightforwardly use Astrometry.net for astrometric calibration and then SExtractor for source-object extraction. The new software also enables astrometric calibration by SCAMP followed by image visualization with tools that support SIP distortion, but not PV . The software has been incorporated into the image-processing pipelines of the Palomar Transient Factory (PTF), which generate FITS images with headers containing both distortion representations. The software permits the conversion of archived images, such as from the Spitzer Heritage Archive and NASA/IPAC Infrared Science Archive, from SIP to PV or vice versa. This new capability renders unnecessary any new representation, such as the proposed TPV distortion convention.

  15. Cognitive distortions among older adult gamblers in an Asian context.

    Science.gov (United States)

    Subramaniam, Mythily; Chong, Siow Ann; Browning, Colette; Thomas, Shane

    2017-01-01

    The study aims to describe the construct of cognitive distortions based on the narratives of older adult gamblers (aged 60 years and above) in Singapore. Singapore residents (citizens or permanent residents) aged 60 years and above, who were current or past regular gamblers were included in the study. Participants were recruited using a combination of venue based approach, referrals from service providers as well as by snowball sampling. In all, 25 in-depth interviews were conducted with older adult gamblers. The six-step thematic network analysis methodology was adopted for data analysis. The mean age of the participants was 66.2 years. The majority were male (n = 18), of Chinese ethnicity (n = 16), with a mean age of gambling initiation at 24.5 years. Among older adult gamblers, cognitive distortions emerged as a significant global theme comprising three organizing themes-illusion of control, probability control and interpretive control. The organizing themes comprised nine basic themes: perception of gambling as a skill, near miss, concept of luck, superstitious beliefs, entrapment, gambler's fallacy, chasing wins, chasing losses, and beliefs that wins are more than losses. Cognitive distortions were endorsed by all gamblers in the current study and were shown to play a role in both maintaining and escalating the gambling behaviour. While the surface characteristics of the distortions had a culture-specific appearance, the deeper characteristics of the distortions may in fact be more universal than previously thought. Future research must include longitudinal studies to understand causal relationships between cognitive distortions and gambling as well as the role of culture-specific distortions both in the maintenance and treatment of the disorder.

  16. Cognitive distortions among older adult gamblers in an Asian context

    Science.gov (United States)

    Subramaniam, Mythily; Chong, Siow Ann; Browning, Colette; Thomas, Shane

    2017-01-01

    Aims The study aims to describe the construct of cognitive distortions based on the narratives of older adult gamblers (aged 60 years and above) in Singapore. Methods Singapore residents (citizens or permanent residents) aged 60 years and above, who were current or past regular gamblers were included in the study. Participants were recruited using a combination of venue based approach, referrals from service providers as well as by snowball sampling. In all, 25 in-depth interviews were conducted with older adult gamblers. The six-step thematic network analysis methodology was adopted for data analysis. Results The mean age of the participants was 66.2 years. The majority were male (n = 18), of Chinese ethnicity (n = 16), with a mean age of gambling initiation at 24.5 years. Among older adult gamblers, cognitive distortions emerged as a significant global theme comprising three organizing themes–illusion of control, probability control and interpretive control. The organizing themes comprised nine basic themes: perception of gambling as a skill, near miss, concept of luck, superstitious beliefs, entrapment, gambler’s fallacy, chasing wins, chasing losses, and beliefs that wins are more than losses. Conclusions Cognitive distortions were endorsed by all gamblers in the current study and were shown to play a role in both maintaining and escalating the gambling behaviour. While the surface characteristics of the distortions had a culture-specific appearance, the deeper characteristics of the distortions may in fact be more universal than previously thought. Future research must include longitudinal studies to understand causal relationships between cognitive distortions and gambling as well as the role of culture-specific distortions both in the maintenance and treatment of the disorder. PMID:28542389

  17. Cognitive distortions among older adult gamblers in an Asian context.

    Directory of Open Access Journals (Sweden)

    Mythily Subramaniam

    Full Text Available The study aims to describe the construct of cognitive distortions based on the narratives of older adult gamblers (aged 60 years and above in Singapore.Singapore residents (citizens or permanent residents aged 60 years and above, who were current or past regular gamblers were included in the study. Participants were recruited using a combination of venue based approach, referrals from service providers as well as by snowball sampling. In all, 25 in-depth interviews were conducted with older adult gamblers. The six-step thematic network analysis methodology was adopted for data analysis.The mean age of the participants was 66.2 years. The majority were male (n = 18, of Chinese ethnicity (n = 16, with a mean age of gambling initiation at 24.5 years. Among older adult gamblers, cognitive distortions emerged as a significant global theme comprising three organizing themes-illusion of control, probability control and interpretive control. The organizing themes comprised nine basic themes: perception of gambling as a skill, near miss, concept of luck, superstitious beliefs, entrapment, gambler's fallacy, chasing wins, chasing losses, and beliefs that wins are more than losses.Cognitive distortions were endorsed by all gamblers in the current study and were shown to play a role in both maintaining and escalating the gambling behaviour. While the surface characteristics of the distortions had a culture-specific appearance, the deeper characteristics of the distortions may in fact be more universal than previously thought. Future research must include longitudinal studies to understand causal relationships between cognitive distortions and gambling as well as the role of culture-specific distortions both in the maintenance and treatment of the disorder.

  18. Body distortions after massive weight loss: lack of updating of the body schema hypothesis.

    Science.gov (United States)

    Guardia, D; Metral, M; Pigeyre, M; Bauwens, I; Cottencin, O; Luyat, M

    2013-09-01

    Behavioural therapy and bariatric surgery often produce rapid, massive body weight loss that may impact a patient's ability to gauge his/her new body shape. Although the patient is aware of the weight loss, he/she continues to feel obese, as if there was a conflict between the previous body schema and the new one. Here, we report the case of a 40-year-old woman who developed major body distortions after massive weight loss. Psychometric and behavioural assessments revealed strong disturbances in several tasks involving body representation. In particular, we observed abnormal behaviour in a body-scaled action task. Our findings suggest that the rapidity of our patient's weight loss prevented her central nervous system from correctly updating the body schema.

  19. How citation distortions create unfounded authority: analysis of a citation network.

    Science.gov (United States)

    Greenberg, Steven A

    2009-07-20

    To understand belief in a specific scientific claim by studying the pattern of citations among papers stating it. A complete citation network was constructed from all PubMed indexed English literature papers addressing the belief that beta amyloid, a protein accumulated in the brain in Alzheimer's disease, is produced by and injures skeletal muscle of patients with inclusion body myositis. Social network theory and graph theory were used to analyse this network. Citation bias, amplification, and invention, and their effects on determining authority. The network contained 242 papers and 675 citations addressing the belief, with 220,553 citation paths supporting it. Unfounded authority was established by citation bias against papers that refuted or weakened the belief; amplification, the marked expansion of the belief system by papers presenting no data addressing it; and forms of invention such as the conversion of hypothesis into fact through citation alone. Extension of this network into text within grants funded by the National Institutes of Health and obtained through the Freedom of Information Act showed the same phenomena present and sometimes used to justify requests for funding. Citation is both an impartial scholarly method and a powerful form of social communication. Through distortions in its social use that include bias, amplification, and invention, citation can be used to generate information cascades resulting in unfounded authority of claims. Construction and analysis of a claim specific citation network may clarify the nature of a published belief system and expose distorted methods of social citation.

  20. A Critique of Feminist Theory

    Directory of Open Access Journals (Sweden)

    Kathy Lay

    2007-05-01

    Full Text Available Objective: Feminism has grown rapidly in the last 40 years as both a multidisciplinary voice advocating for change and an area of scholarship and theory building. A review of empirical articles describes 17 studies that indicate a wide range of applications of feminist theory, but theory is applied primarily as a lens for other issues, rather than to expand theory development. Advocacy and philosophical views seem to overshadow theory development. Suggestions for improving feminist theory are offered.

  1. Adverse childhood experiences worsen cognitive distortion during adult bipolar depression.

    Science.gov (United States)

    Poletti, Sara; Colombo, Cristina; Benedetti, Francesco

    2014-11-01

    Cognitive distortion is a central feature of depression, encompassing negative thinking, dysfunctional personality styles and dysfunctional attitudes. It has been hypothesized that ACEs could increase the vulnerability to depression by contributing to the development of a stable negative cognitive style. Nevertheless, little research has been carried out on possible associations between adverse childhood experiences (ACEs) and cognitive distortion, and whether any gender differences exist. The aim of this study was to examine the association between ACEs and cognitive distortions and possible differences between genders in a sample of patients affected by bipolar disorder. 130 patients with bipolar disorder (BD) (46 men and 84 females), completed the Risky Family Questionnaire to assess ACEs and the Cognition Questionnaire (CQ) to assess cognitive distortions. A positive association was found between ACE and the CQ total score. Investigating the 5 dimensions assessed through the CQ, only the dimension "generalization across situations" was significantly associated to ACE. An interaction between ACE and gender was found for "generalization across situations", while no differential effect among females and males was found for CQ total score. This is the first study to report a relationship between negative past experiences and depressive cognitive distortions in subjects affected by BD. Growing in a family environment affected by harsh parenting seems to a cognitive vulnerability to depression; this effect is especially strong in females. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Correcting low-frequency phase distortion in electroglottograph waveforms.

    Science.gov (United States)

    Rothenberg, Martin

    2002-03-01

    Dynamic high-pass filtering with a -3 dB frequency that is a factor of ten or more below the voice fundamental frequency has a negligible effect on the amplitudes of the Fourier components of an EGG waveform. However, such a filter can significantly distort the waveform due to distortion in the phase or time alignment of these Fourier components. Such high-pass filtering can be introduced purposefully to stabilize the waveform by attenuating low-frequency noise, or may be an undesired effect of using an amplification or data acquisition system designed for acoustic signals. For a given voice fundamental frequency, the amount of distortion depends greatly on the order or attenuation characteristics of the filter and on the type of EGG waveform. Both a high-order filter and a breathy voice tend to increase the amount of distortion. If the characteristics of the high-pass filter are known, there are a number of digital filter techniques that can be used to reduce the phase distortion. However, it is shown that a relatively simple analogue network can also be used to obtain a correction that suffices for most applications. If the precise characteristics of the filter are not known, the response to a square wave can be used to adjust the compensator parameters for an optimal correction.

  3. Development, comparison, and evaluation of software for radial distortion elimination

    Science.gov (United States)

    Papadaki, A. I.; Georgopoulos, A.

    2015-05-01

    Lately the interest of Computer Vision and Photogrammetry community has been focused on the automation of the processes of identification and elimination of the radial distortion, with the aim to correct the image coordinates and finally to obtain digital images with reliable geometric information. This effort has reached the point of development of commercial or free image processing software, claiming that it can automatically identify and remove the radial distortion from an image. In this paper in depth research has been conducted about the radial distortion and the methods of its identification and elimination. Specifically, it has been attempted to evaluate software as the aforementioned, about its effectiveness, accuracy and applicability on the elimination of the radial distortion from images. For the attainment of the desired aim, four different methods of comparison and evaluation of the performance of the software, with respect to the correction of an image, have been employed. The applied methods are (i) the optical evaluation of the produced digital images, (ii) the subtraction of the images, (iii) the comparison of the curves of the remaining radial distortion in the images and (iv) the comparison of the results from the orientation of an image pair. However, it was really important to have a benchmark for the evaluation, in order to ensure the objectivity and accuracy of the comparison. Therefore, a new reliable algorithm has been developed, which was of known and controllable accuracy. The results of these comparisons are presented and evaluated for their reliability and usefulness.

  4. Distortion-Based Link Adaptation for Wireless Video Transmission

    Directory of Open Access Journals (Sweden)

    Andrew Nix

    2008-06-01

    Full Text Available Wireless local area networks (WLANs such as IEEE 802.11a/g utilise numerous transmission modes, each providing different throughputs and reliability levels. Most link adaptation algorithms proposed in the literature (i maximise the error-free data throughput, (ii do not take into account the content of the data stream, and (iii rely strongly on the use of ARQ. Low-latency applications, such as real-time video transmission, do not permit large numbers of retransmission. In this paper, a novel link adaptation scheme is presented that improves the quality of service (QoS for video transmission. Rather than maximising the error-free throughput, our scheme minimises the video distortion of the received sequence. With the use of simple and local rate distortion measures and end-to-end distortion models at the video encoder, the proposed scheme estimates the received video distortion at the current transmission rate, as well as on the adjacent lower and higher rates. This allows the system to select the link-speed which offers the lowest distortion and to adapt to the channel conditions. Simulation results are presented using the MPEG-4/AVC H.264 video compression standard over IEEE 802.11g. The results show that the proposed system closely follows the optimum theoretic solution.

  5. Accuracy evaluation of optical distortion calibration by digital image correlation

    Science.gov (United States)

    Gao, Zeren; Zhang, Qingchuan; Su, Yong; Wu, Shangquan

    2017-11-01

    Due to its convenience of operation, the camera calibration algorithm, which is based on the plane template, is widely used in image measurement, computer vision and other fields. How to select a suitable distortion model is always a problem to be solved. Therefore, there is an urgent need for an experimental evaluation of the accuracy of camera distortion calibrations. This paper presents an experimental method for evaluating camera distortion calibration accuracy, which is easy to implement, has high precision, and is suitable for a variety of commonly used lens. First, we use the digital image correlation method to calculate the in-plane rigid body displacement field of an image displayed on a liquid crystal display before and after translation, as captured with a camera. Next, we use a calibration board to calibrate the camera to obtain calibration parameters which are used to correct calculation points of the image before and after deformation. The displacement field before and after correction is compared to analyze the distortion calibration results. Experiments were carried out to evaluate the performance of two commonly used industrial camera lenses for four commonly used distortion models.

  6. Asteroseismic Theory of Rapidly Oscillating Ap Stars

    Indian Academy of Sciences (India)

    Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately.

  7. Modeling of radial asymmetry in lens distortion facilitated by modern optimization techniques

    CSIR Research Space (South Africa)

    De Villiers, Johan P

    2010-01-18

    Full Text Available Most current lens distortion models use only a few terms of Brown's model, which assumes that the radial distortion is dependant only on the distance from the distortion centre, and an additive tangential distortion can be used to correct lens de...

  8. The Interpersonal Cognitive Distortions Scale: development and psychometric characteristics.

    Science.gov (United States)

    Hamamci, Zeynep; Büyüköztürk, Sener

    2004-08-01

    In this study, an Interpersonal Cognitive Distortions Scale was developed to assess cognitive distortions in individuals' interpersonal relationships. The sample comprised 425 university students. A factor analysis yielded three factors: Interpersonal Rejection, Unrealistic Relationship Expectation and Interpersonal Misperception. To examine construct validity the correlations between the scores on the Interpersonal Cognitive Distortions Scale and the Automatic Thoughts Scale (.54), the Irrational Belief Scale (.54), and the Conflict Tendency Scale (.53) were estimated. The first factor, the second factor, and the total scale discriminated married individuals who had low and high conflict intensity and conflict frequency. The reliability of the scale was estimated by performing a test-retest correlation (.74). Cronbach internal consistency coefficient alpha was .67.

  9. Segregation distortion of mouse t haplotypes the molecular basis emerges.

    Science.gov (United States)

    Schimenti, J

    2000-06-01

    The t haplotype is an ancestral version of proximal mouse chromosome 17 that has evolved mechanisms to persist as an intact genomic variant in mouse populations. t haplotypes contain mutations that affect embryonic development, male fertility and male transmission ratio distortion (TRD). Collectively, these mutations drive the evolutionary success of t haplotypes, a phenomenon that remains one of the longstanding mysteries of mouse genetics. Molecular genetic analysis of TRD has been confounded by inversions that arose to lock together the various elements of this complex trait. Our first molecular glimpse of the TRD mechanism has finally been revealed with the cloning of the t complex responder (Tcr) locus, a chimeric kinase with a genetically cis active effect. Whereas + sperm in a +/t male have impaired flagellar function caused by the deleterious action of trans-active, t-haplotype-encoded 'distorters,' the mutant activity of Tcr counterbalances the distorter effects, maintaining the motility and fertilizing ability of t sperm.

  10. Pulsar Pair Cascades in a Distorted Magnetic Dipole Field

    Science.gov (United States)

    Harding, Alice K.; Muslimov, Alex G.

    2010-01-01

    We investigate the effect of a distorted neutron star dipole magnetic field on pulsar pair cascade multiplicity and pair death lines. Using a simple model for a distorted dipole field that produces an offset polar cap (PC), we derive the accelerating electric field above the PC in space-charge-limited flow. We find that even a modest azimuthally asymmetric distortion can significantly increase the accelerating electric field on one side of the PC and, combined with a smaller field line radius of curvature, leads to larger pair multiplicity. The death line for producing pairs by curvature radiation moves downward in the P-P-dot diagram, allowing high pair multiplicities in a larger percentage of the radio pulsar population. These results could have important implications for the radio pulsar population, high energy pulsed emission, and the pulsar contribution to cosmic ray positrons.

  11. Distorted Images of Islam: The Case of Former Yugoslavia

    Directory of Open Access Journals (Sweden)

    Fikret Karčić

    1995-12-01

    Full Text Available Since the 1980s, the former Yugoslavia has witnessed increasing distortion of images of Islam in academic publications, media, and public life. This process has been connected with the changes in power structure in Serbia, and with the new ideological orientation of the Serbian leadership which opted for national exclusivism (ethno fascism. The Muslims have been portrayed as a threat to the realization of the Serbian hegemonist project. In order to mobilize domestic public opinion against the Muslims and to justify future acts against them in the eyes of the West, the Serbian leadership needed an image of Islam as a totalitarian, inherently violent, and culturally alien system on European soil. Such a distorted image has been provided by some influential Serbian orientalists, the Orthodox Church, and some historians. Due to these distortions, these Serbian intellectual circles have become accomplices in the crimes committed against the Muslims in former Yugoslavia during 1992-1995.

  12. Control of nanoparticle self-assemblies using distorted liquid crystals

    Science.gov (United States)

    Lacaze, Emmanuelle; Coursault, Delphine

    This chapter concerns the structure and the optical properties of nanoparticle (NP)/liquid crystal (LC) composites in the presence of LC distortion. After a first description of the general behaviour of NPs at the proximity of distorted LC areas, the first section of the chapter discusses the stabilization of the LC phases, characterized by the presence of topological defects in presence of NPs. The assemblies of NPs induced by distorted LC films is addressed in the second section. The last section then extensively develops the structure and optical properties of NP assemblies created within topological defects. Specific localisation and orientations of the NPs will be discussed, but also possible control of the size and shape of the NP assemblies, together with control of the distances between NPs in the assemblies, leading to original optical properties of the composites as far as uorescent or gold NPs are concerned.

  13. Metering error quantification under voltage and current waveform distortion

    Science.gov (United States)

    Wang, Tao; Wang, Jia; Xie, Zhi; Zhang, Ran

    2017-09-01

    With integration of more and more renewable energies and distortion loads into power grid, the voltage and current waveform distortion results in metering error in the smart meters. Because of the negative effects on the metering accuracy and fairness, it is an important subject to study energy metering combined error. In this paper, after the comparing between metering theoretical value and real recorded value under different meter modes for linear and nonlinear loads, a quantification method of metering mode error is proposed under waveform distortion. Based on the metering and time-division multiplier principles, a quantification method of metering accuracy error is proposed also. Analyzing the mode error and accuracy error, a comprehensive error analysis method is presented which is suitable for new energy and nonlinear loads. The proposed method has been proved by simulation.

  14. Multiview Trajectory Mapping Using Homography with Lens Distortion Correction

    Directory of Open Access Journals (Sweden)

    Andrea Cavallaro

    2008-11-01

    Full Text Available We present a trajectory mapping algorithm for a distributed camera setting that is based on statistical homography estimation accounting for the distortion introduced by camera lenses. Unlike traditional approaches based on the direct linear transformation (DLT algorithm and singular value decomposition (SVD, the planar homography estimation is derived from renormalization. In addition to this, the algorithm explicitly introduces a correction parameter to account for the nonlinear radial lens distortion, thus improving the accuracy of the transformation. We demonstrate the proposed algorithm by generating mosaics of the observed scenes and by registering the spatial locations of moving objects (trajectories from multiple cameras on the mosaics. Moreover, we objectively compare the transformed trajectories with those obtained by SVD and least mean square (LMS methods on standard datasets and demonstrate the advantages of the renormalization and the lens distortion correction.

  15. Multiview Trajectory Mapping Using Homography with Lens Distortion Correction

    Directory of Open Access Journals (Sweden)

    Kayumbi Gabin

    2008-01-01

    Full Text Available Abstract We present a trajectory mapping algorithm for a distributed camera setting that is based on statistical homography estimation accounting for the distortion introduced by camera lenses. Unlike traditional approaches based on the direct linear transformation (DLT algorithm and singular value decomposition (SVD, the planar homography estimation is derived from renormalization. In addition to this, the algorithm explicitly introduces a correction parameter to account for the nonlinear radial lens distortion, thus improving the accuracy of the transformation. We demonstrate the proposed algorithm by generating mosaics of the observed scenes and by registering the spatial locations of moving objects (trajectories from multiple cameras on the mosaics. Moreover, we objectively compare the transformed trajectories with those obtained by SVD and least mean square (LMS methods on standard datasets and demonstrate the advantages of the renormalization and the lens distortion correction.

  16. Modeling Distortion Effects in Class-D Amplifier Filter Inductors

    DEFF Research Database (Denmark)

    Knott, Arnold; Stegenborg-Andersen, Tore; Thomsen, Ole Cornelius

    2010-01-01

    Distortion is generally accepted as a quantifier to judge the quality of audio power amplifiers. In switchmode power amplifiers various mechanisms influence this performance measure. After giving an overview of those, this paper focuses on the particular effect of the nonlinearity of the output...... filter components on the audio performance. While the physical reasons for both, the capacitor and the inductor induced distortion are given, the practical in depth demonstration is done for the inductor only. This includes measuring the inductors performance, modeling through fitting and resulting...... into simulation models. The fitted models achieve distortion values between 0.03 % and 0.2 % as a basis to enable the design of a 200 W amplifier....

  17. Predictive Rate-Distortion for Infinite-Order Markov Processes

    Science.gov (United States)

    Marzen, Sarah E.; Crutchfield, James P.

    2016-06-01

    Predictive rate-distortion analysis suffers from the curse of dimensionality: clustering arbitrarily long pasts to retain information about arbitrarily long futures requires resources that typically grow exponentially with length. The challenge is compounded for infinite-order Markov processes, since conditioning on finite sequences cannot capture all of their past dependencies. Spectral arguments confirm a popular intuition: algorithms that cluster finite-length sequences fail dramatically when the underlying process has long-range temporal correlations and can fail even for processes generated by finite-memory hidden Markov models. We circumvent the curse of dimensionality in rate-distortion analysis of finite- and infinite-order processes by casting predictive rate-distortion objective functions in terms of the forward- and reverse-time causal states of computational mechanics. Examples demonstrate that the resulting algorithms yield substantial improvements.

  18. Attitude May Be Everything, But Is Everything an Attitude? Cognitive Distortions May Not Be Evaluations of Rape.

    Science.gov (United States)

    Nunes, Kevin L; Hermann, Chantal A; White, Kristen; Pettersen, Cathrine; Bumby, Kurt

    2016-01-18

    Cognitive distortions are often referred to as attitudes toward rape in theory, research, and clinical practice pertaining to sexual aggression. In the social-psychological literature, however, attitudes are typically defined as evaluations; thus, in this context, attitudes toward rape are considered evaluations of rape (e.g., rape is negative vs. positive). The purpose of the current study was to explore whether a widely used measure of cognitive distortions (RAPE Scale; Bumby, 1996) assesses evaluation of rape, and, if not, whether evaluation of rape and the cognitions assessed by the RAPE Scale are independently associated with sexually aggressive behavior. Participants (660 male undergraduate students) completed the RAPE Scale as well as measures of evaluation of rape and sexually aggressive behavior. An exploratory factor analysis revealed that the RAPE Scale items formed a correlated but distinct factor from the Evaluation of Rape Scale items. Regression analyses indicated that the Evaluation of Rape Scale and the RAPE Scale had small to moderate independent associations with self-report measures of sexually aggressive behavior. Our results suggest that evaluation of rape may be distinct from cognitive distortions regarding rape, and both evaluation and cognitive distortions may be relevant for understanding sexual violence. © The Author(s) 2016.

  19. Digital image processing for the rectification of television camera distortions.

    Science.gov (United States)

    Rindfleisch, T. C.

    1971-01-01

    All television systems introduce distortions into the imagery they record which influence the results of quantitative photometric and geometric measurements. Digital computer techniques provide a powerful approach to the calibration and rectification of these systematic effects. Nonlinear as well as linear problems can be attacked with flexibility and precision. Methods which have been developed and applied for the removal of structured system noises and the correction of photometric, geometric, and resolution distortions in vidicon systems are briefly described. Examples are given of results derived primarily from the Mariner Mars 1969 television experiment.

  20. Distortion of Crabbed Bunch Due to the Electron Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L; Raubenheimer, T.; /SLAC

    2008-05-28

    In order to improve the luminosity, two crab cavities have been installed in KEKB HER and LER [1]. Since there is only one crab cavity in each ring, the crab cavity generates a horizontally titled bunch along the whole ring. The achieved specific luminosity with crabbed bunch is higher, but it is not as high as that from beam-beam simulation [2]. One of the suspicions is the electron cloud. The electron cloud in LER (positron beam) may distort the crabbed bunch and cause the luminosity drop. This note briefly estimates the bunch shape distortion due to the electron cloud in KEKB LER.

  1. Temperature and distortion transients in gas tungsten-arc weldments

    Energy Technology Data Exchange (ETDEWEB)

    Glickstein, S.S.; Friedman, E.

    1979-10-01

    An analysis and test program to develop a fundamental understanding of the gas tungsten-arc welding process has been undertaken at the Bettis Atomic Power Laboratory to develop techniques to determine and control the various welding parameters and weldment conditions so as to result in optimum weld response characteristics. These response characteristics include depth of penetration, weld bead configuration, weld bead sink and roll, distortion, and cracking sensitivity. The results are documented of that part of the program devoted to analytical and experimental investigations of temperatures, weld bead dimensions, and distortions for moving gas tungsten-arc welds applied to Alloy 600 plates.

  2. Analytical evaluation of nonlinear distortion effects on multicarrier signals

    CERN Document Server

    Araújo, Theresa

    2015-01-01

    Due to their ability to support reliable high quality of service as well as spectral and power efficiency, multicarrier modulation systems have found increasing use in modern communications services. However, one of the main drawbacks of these systems is their vulnerability to nonlinear distortion effects. Analytical Evaluation of Nonlinear Distortion Effects on Multicarrier Signals details a unified approach to well-known analytical results on memoryless nonlinearities that takes advantage of the Gaussian behavior of multicarrier signals.Sharing new insights into the behavior of nonlinearly d

  3. PANINI PROJECTION EFFECT AS MEANS OF REDUCING PERSPECTIVE DISTORTIONS

    Directory of Open Access Journals (Sweden)

    P. A. Kachanov

    2015-01-01

    Full Text Available The method based on Panini projection to reduce perspective distortions of images with wide viewing angle is considered. The analysis of the features of construction of Panini projection is provided. A realization of the effect on the graphic accelerators as a result of post-processing is proposed. The results of using the described effect in computer graphics were obtained. A comparison of images in the perspective projection and Panini projection was carried out. It is shown that perspective projection of a three-dimensional scene onto the surface of a parabolic cylinder reduces distortions.

  4. Identification and control of harmonic distortions report on Furnas experience

    Energy Technology Data Exchange (ETDEWEB)

    Mantuano Filho, Salvatore; Medeiros, Jose Roberto de; Bezerra, Luiz Roberto; Oliveira, Denise Borges de; Praca, Antonio Augusto Souza; Paiva Fontes, Marco Antonio de; Marques, Luiz Carlos Borges C. [FURNAS, Rio de Janeiro, RJ (Brazil)

    1994-12-31

    This paper describes FURNAS experience on identification and control of harmonic distortions obtained from conservation of system operation and research for solutions. Special attention is paid to the harmonic overload observed at Ibiuna substation, the receiving end of the FURNAS HVDC transmission of the Itaipu 50 Hz energy, and the solutions that have been adopted. Methods of measurement and digital simulation have been developed and successfully tested so far. The present stage of those methods will be described. Not less important is the need for a specific legislation on harmonic distortion as explained in this paper. (author) 6 refs., 2 figs.

  5. View Angle Tilting Echo Planar Imaging for Distortion Correction

    OpenAIRE

    Ahn, Sinyeob; Hu, Xiaoping

    2011-01-01

    Geometric distortion caused by field inhomogeneity along the phase-encode (PE) direction is one of the most prominent artifacts due to a relatively low effective bandwidth along that direction in magnetic resonance echo planar imaging (EPI). This work describes a method for correcting in-plane image distortion along the PE direction using a view angle tilting (VAT) imaging technique in spin-echo EPI (SE-EPI). SE-EPI with VAT (SE-EPI-VAT) utilizes the addition of gradient blips along the slice...

  6. The problem of applying information theory to efficient image transmission.

    Science.gov (United States)

    Sakrison, D. J.

    1973-01-01

    The main ideas of Shannon's (1948, 1960) theory of source encoding with a fidelity constraint, more commonly known as rate distortion theory, are summarized. The theory was specifically intended to provide a theoretical basis for efficient transmission of information such as images. What the theory has to contribute to the problem is demonstrated. Difficulties that impeded application of the theory to image transmission, and current efforts to solve these difficulties are discussed.

  7. Enhanced Modified Bark Spectral Distortion (EMBSD): An objective speech quality measure based on audible distortion and cognition model

    Science.gov (United States)

    Yang, Wonho

    The Speech Processing Lab at Temple University developed an objective speech quality measure called the Modified Bark Spectral Distortion (MBSD). The MBSD uses auditory perception models derived from psychoacoustic studies. The MBSD measure extends the Bark Spectral Distortion (BSD) method by incorporating noise making threshold to differentiate audible/inaudible distortions. The performance of the MBSD was comparable to that of the ITU-T Recommendation P.861 for various coding distortions. Based on the experiments with Time Division Multiple Access (TDMA) data that contains distortions encountered in real network applications, modifications have been made to the MBSD algorithm. These are: use of the first 15 loudness components, normalization of loudness vectors, deletion of the spreading function in the noise masking threshold calculation, and use of a new cognition model based on postmasking effects. The Enhanced MBSD (EMBSD) shows significant improvement over the MBSD for TDMA data. Also, the performance of the EMBSD is better than that of the ITU-T Recommendation P.861 and Measuring Normalizing Blocks (MNB) measures for TDMA data. The performance of the EMBSD was compared to various other objective speech quality measures with the speech data including a wide range of distortion conditions. The EMBSD showed clear improvement over the MBSD and had the correlation coefficient of 0.89 for the conditions of MNRUs, codecs, tandem cases, bit errors, and frame erasures. Mean Opinion Score (MOS) has been used to evaluate objective speech quality measures. Recognizing the procedural difference between the MOS test and current objective speech quality measures, it is proposed that current objective speech quality measures should be evaluated with Degradation Mean Opinion Score (DMOS). The Pearson product-moment correlation coefficient has been the main performance parameter for evaluation of objective speech quality measures. The Standard Error of the Estimates (SEE

  8. Hierarchical Clustering and the Concept of Space Distortion.

    Science.gov (United States)

    Hubert, Lawrence; Schultz, James

    An empirical assesssment of the space distortion properties of two prototypic hierarchical clustering procedures is given in terms of an occupancy model developed from combinatorics. Using one simple example, the single-link and complete-link clustering strategies now in common use in the behavioral sciences are empirically shown to be space…

  9. Turkish Version of the Cognitive Distortions Questionnaire: Psychometric Properties.

    Science.gov (United States)

    Batmaz, Sedat; Kocbiyik, Sibel; Yuncu, Ozgur Ahmet

    2015-01-01

    Cognitive distortions are interrelated with all layers of cognitions, and they may be part of the treatment once they are accessed, identified, labeled, and changed. From both a research and a clinical perspective, it is of utmost importance to disentangle cognitive distortions from similar constructs. Recently, the Cognitive Distortions Questionnaire (CD-Quest), a brief and comprehensive measure, was developed to assess both the frequency and the intensity of cognitive distortions. The aim of the present study was to assess the psychometric properties of the Turkish version of the CD-Quest in a psychiatric outpatient sample. Demographic and clinical data of the participants were analyzed by descriptive statistics. For group comparisons, Student's t-test was applied. An exploratory principal components factor analysis was performed, followed by an oblique rotation. To assess the internal consistency of the scale Cronbach's α was computed. The correlation coefficient was calculated for test-retest reliability over a 4-week period. For concurrent validity, bivariate Pearson correlation analyses were conducted with the measures of mood severity and negatively biased cognitions. The results revealed that the scale had excellent internal consistency, good test-retest reliability, unidimensional factor structure, and evidence of concurrent and discriminant validity.

  10. Turkish Version of the Cognitive Distortions Questionnaire: Psychometric Properties

    Directory of Open Access Journals (Sweden)

    Sedat Batmaz

    2015-01-01

    Full Text Available Cognitive distortions are interrelated with all layers of cognitions, and they may be part of the treatment once they are accessed, identified, labeled, and changed. From both a research and a clinical perspective, it is of utmost importance to disentangle cognitive distortions from similar constructs. Recently, the Cognitive Distortions Questionnaire (CD-Quest, a brief and comprehensive measure, was developed to assess both the frequency and the intensity of cognitive distortions. The aim of the present study was to assess the psychometric properties of the Turkish version of the CD-Quest in a psychiatric outpatient sample. Demographic and clinical data of the participants were analyzed by descriptive statistics. For group comparisons, Student’s t-test was applied. An exploratory principal components factor analysis was performed, followed by an oblique rotation. To assess the internal consistency of the scale Cronbach’s α was computed. The correlation coefficient was calculated for test-retest reliability over a 4-week period. For concurrent validity, bivariate Pearson correlation analyses were conducted with the measures of mood severity and negatively biased cognitions. The results revealed that the scale had excellent internal consistency, good test-retest reliability, unidimensional factor structure, and evidence of concurrent and discriminant validity.

  11. Determination of Total Harmonic Distortion (THD) on a 33kv ...

    African Journals Online (AJOL)

    This paper presents the estimation of Total Harmonic Distortion (THD) of the Distribution lines in the 33kV distribution network of Island Business District, Eko Electricity Distribution Plc, taken as a case study using a set of busbar voltage results, obtained from previous studies on power flow and harmonic analyses of each ...

  12. A new interpretation of distortion artifacts in sweep measurements

    DEFF Research Database (Denmark)

    Torras Rosell, Antoni; Jacobsen, Finn

    2011-01-01

    The characterization of acoustical spaces by means of impulse response measurements is often biased by the nonlinear behavior of the loudspeaker used to excite the system under test. In this context the distortion immunity provided by the sweep technique has been investigated. The results show...

  13. Information Distortion in the Evaluation of a Single Option

    Science.gov (United States)

    Bond, Samuel D.; Carlson, Kurt A.; Meloy, Margaret G.; Russo, J. Edward; Tanner, Robin J.

    2007-01-01

    Extending previous work on biased predecisional processing, we investigate the distortion of information during the evaluation of a single option. A coherence-based account of the evaluation task suggests that individuals will form an initial assessment of favorability toward the option and then bias their evaluation of subsequent information to…

  14. Measurement, analysis and correction of the closed orbit distortion ...

    Indian Academy of Sciences (India)

    2013-02-01

    Feb 1, 2013 ... Abstract. The paper presents the measurement, analysis and correction of closed orbit distortion. (COD) in Indus-2 at 550 MeV injection energy and 2 GeV synchrotron radiation user run energy. The measured COD was analysed and fitted to understand major sources of errors in terms of the effective ...

  15. An Accurate Projector Calibration Method Based on Polynomial Distortion Representation

    Directory of Open Access Journals (Sweden)

    Miao Liu

    2015-10-01

    Full Text Available In structure light measurement systems or 3D printing systems, the errors caused by optical distortion of a digital projector always affect the precision performance and cannot be ignored. Existing methods to calibrate the projection distortion rely on calibration plate and photogrammetry, so the calibration performance is largely affected by the quality of the plate and the imaging system. This paper proposes a new projector calibration approach that makes use of photodiodes to directly detect the light emitted from a digital projector. By analyzing the output sequence of the photoelectric module, the pixel coordinates can be accurately obtained by the curve fitting method. A polynomial distortion representation is employed to reduce the residuals of the traditional distortion representation model. Experimental results and performance evaluation show that the proposed calibration method is able to avoid most of the disadvantages in traditional methods and achieves a higher accuracy. This proposed method is also practically applicable to evaluate the geometric optical performance of other optical projection system.

  16. Effects of galvanic distortions on magnetotelluric data: Interpretation ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    distortion is the accumulation of space charge along boundaries of shallow inhomogeneities. The major contribution comes from the surficial bodies, which lie within the skin depth at the highest frequency. This affects the entire sounding curve at all fre- quencies giving rise to static shift. Studies by Park et al (1983); ...

  17. Phantom limb phenomenon as an example of body image distortion

    Directory of Open Access Journals (Sweden)

    Razmus Magdalena

    2017-06-01

    Full Text Available Introduction: The perception of one’s own body, its mental representation, and emotional attitude to it are the components of so-called “body image” [1]. The aim of the research was to analyse phantom pain and non-painful phantom sensations as results of limb loss and to explain them in terms of body image distortion.

  18. Distributed Remote Vector Gaussian Source Coding with Covariance Distortion Constraints

    DEFF Research Database (Denmark)

    Zahedi, Adel; Østergaard, Jan; Jensen, Søren Holdt

    2014-01-01

    of side information at the decoder. For this problem, we derive lower and upper bounds on the rate-distortion function (RDF) for the Gaussian case, which in general do not coincide. We then provide some cases, where the RDF can be derived exactly. We also show that previous results on specific instances...

  19. Source Coding in Networks with Covariance Distortion Constraints

    DEFF Research Database (Denmark)

    Zahedi, Adel; Østergaard, Jan; Jensen, Søren Holdt

    2016-01-01

    -distortion function (RDF). We then study the special cases and applications of this result. We show that two well-studied source coding problems, i.e. remote vector Gaussian Wyner-Ziv problems with mean-squared error and mutual information constraints are in fact special cases of our results. Finally, we apply our...

  20. Measurement, analysis and correction of the closed orbit distortion ...

    Indian Academy of Sciences (India)

    The paper presents the measurement, analysis and correction of closed orbit distortion (COD) in Indus-2 at 550 MeV injection energy and 2 GeV synchrotron radiation user run energy. The measured COD was analysed and fitted to understand major sources of errors in terms of the effective quadrupole misalignments.

  1. An Accurate Projector Calibration Method Based on Polynomial Distortion Representation

    Science.gov (United States)

    Liu, Miao; Sun, Changku; Huang, Shujun; Zhang, Zonghua

    2015-01-01

    In structure light measurement systems or 3D printing systems, the errors caused by optical distortion of a digital projector always affect the precision performance and cannot be ignored. Existing methods to calibrate the projection distortion rely on calibration plate and photogrammetry, so the calibration performance is largely affected by the quality of the plate and the imaging system. This paper proposes a new projector calibration approach that makes use of photodiodes to directly detect the light emitted from a digital projector. By analyzing the output sequence of the photoelectric module, the pixel coordinates can be accurately obtained by the curve fitting method. A polynomial distortion representation is employed to reduce the residuals of the traditional distortion representation model. Experimental results and performance evaluation show that the proposed calibration method is able to avoid most of the disadvantages in traditional methods and achieves a higher accuracy. This proposed method is also practically applicable to evaluate the geometric optical performance of other optical projection system. PMID:26492247

  2. Employment-Related Motivational Distortion: Its Nature, Measurement, and Reduction

    Science.gov (United States)

    Hakstian, A. Ralph; Ng, Ee-Ling

    2005-01-01

    The behavioral variable employment-related motivational distortion (EMD) was defined and measured. In Study 1, a sample of 250 undergraduates completed the California Psychological Inventory (CPI), Form 434, on two separate occasions in which they responded (a) honestly and (b) as if applying for a job they valued. Four different change measures…

  3. Curious Sex Ratios and Cytoplasmic Genes Microbes Can Distort ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 6. Curious Sex Ratios and Cytoplasmic Genes Microbes Can Distort the Sex Ratio of Populations. Stephen J Freeland Laurence D Hurst. General Article Volume 2 Issue 6 June 1997 pp 68-78 ...

  4. Distortion product otoacoustic emission fine structure of symphony orchestra musicians

    DEFF Research Database (Denmark)

    Reuter, Karen; Hammershøi, Dorte

    losses than puretone audiometry. The distortion product otoacoustic emission (DPOAE) fine structure is obtained when the ear is stimulated by dual tone stimuli using a high frequency resolution. It is characterized by quasi-periodic variations across frequency, as it can be observed in the hearing...

  5. Distortion product otoacoustic emission fine structure of symphony orchestra musicians

    DEFF Research Database (Denmark)

    Reuter, Karen; Hammershøi, Dorte

    2006-01-01

    losses than pure-tone audiometry. The distortion product otoacoustic emission (DPOAE) fine structure is obtained when the ear is stiumulated by dual tone stimuli using a high frequency resolution. It is characterized by quasi-periodic variations across frequency, as it can be observed in the hearing...

  6. Effects of galvanic distortions on magnetotelluric data: Interpretation ...

    Indian Academy of Sciences (India)

    Direct current sensitivity studies show that the behaviour of MT static shift can be estimated using DC resistivity measurements close to the MT sounding station to appreciable depths. The distorted data set is corrected using the MT response for DRS model and further subject to joint inversion with DRS data. Joint inversion ...

  7. Body Dysmorphic Disorder: Easing the Distress of Distortion.

    Science.gov (United States)

    Fore, Cynthia M.

    People who suffer from body dysmorphic disorder believe that their body is defected and that this defect makes them ugly. Their distorted body image can be precipitated by many internal and external factors and as a result of their imagined defect, these normal-appearing individuals exhibit self-defeating behaviors. The disorder can lead to the…

  8. Effects Of Field Distortions In Ih-apf Linac

    CERN Document Server

    Kapin, Valery; Yamada, S

    2004-01-01

    The project on developing compact medical accelera-tors for the tumor therapy using carbon ions has been started at the National Institute of Radiological Sciences (NIRS). Alternating-phase-focused (APF) linac using an interdigital H-mode (IH) cavity has been proposed for the injector linac. The IH-cavity is doubly ridged circular resonator loaded by the drift-tubes mounted on ridges with supporting stems. The effects of intrinsic and random field distortions in a practical design of the 4-MeV/u 200 MHz IH-APF linac are considered. The intrinsic field distortions in IH-cavity are caused by the asymmetry of the gap field due to presence of the drift-tube supporting stems and pair of ridges. The random field distortions are caused by drift-tube misalignments and non-regular deviations of the voltage distribution from programmed law. The RF fields in IH-cavity have been calculated using Microwave Studio (MWS) code. The effects of field distortions on beam dynamics have been simulated numerically.

  9. Communication Distortion: An Intercultural Lesson from the Visa Application Process.

    Science.gov (United States)

    Olaniran, Bolanle A.; Williams, David E.

    1995-01-01

    Investigates a visa interview process involving applicants from a West African country and interviewers from a Western culture to examine the effects of intercultural factors on communication distortion. Examines speech pattern, body posture, and eye contact, along with information disclosure and verbal aggression. Suggests that different cultures…

  10. Pathophysiological Distortions in Time Perception and Timed Performance

    Science.gov (United States)

    Allman, Melissa J.; Meck, Warren H.

    2012-01-01

    Distortions in time perception and timed performance are presented by a number of different neurological and psychiatric conditions (e.g. Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder and autism). As a consequence, the primary focus of this review is on factors that define or produce systematic changes in the…

  11. Modeling and Compensation of Nonlinear Distortion in Horn Loudspeakers

    NARCIS (Netherlands)

    Schurer, Hans; Berkhoff, Arthur P.; Slump, Cornelis H.; Herrmann, O.E.

    1994-01-01

    Horn loaded compression drivers are widely used in the area where high sound pressure levels together with good directivity characteristics are needed. Major disadvantage of this kind of drivers is the considerable amount of nonlinear distortion. Due to the quite high air pressures in the driver the

  12. Modeling and prediction of turbulence-induced wavefront distortions

    NARCIS (Netherlands)

    Fraanje, P.R.; Doelman, N.J.

    2010-01-01

    In recent years various researchers have proposed an optimal control approach for the rejection of turbulence-induced wavefront distortions in an AO system. The essential element in the design of an optimal controller is the choice for the turbulence model, which predicts the turbulence to

  13. Epipolar Rectification with Minimum Perspective Distortion for Oblique Images.

    Science.gov (United States)

    Liu, Jianchen; Guo, Bingxuan; Jiang, Wanshou; Gong, Weishu; Xiao, Xiongwu

    2016-11-07

    Epipolar rectification is of great importance for 3D modeling by using UAV (Unmanned Aerial Vehicle) images; however, the existing methods seldom consider the perspective distortion relative to surface planes. Therefore, an algorithm for the rectification of oblique images is proposed and implemented in detail. The basic principle is to minimize the rectified images' perspective distortion relative to the reference planes. First, this minimization problem is formulated as a cost function that is constructed by the tangent value of angle deformation; second, it provides a great deal of flexibility on using different reference planes, such as roofs and the façades of buildings, to generate rectified images. Furthermore, a reasonable scale is acquired according to the dihedral angle between the rectified image plane and the original image plane. The low-quality regions of oblique images are cropped out according to the distortion size. Experimental results revealed that the proposed rectification method can result in improved matching precision (Semi-global dense matching). The matching precision is increased by about 30% for roofs and increased by just 1% for façades, while the façades are not parallel to the baseline. In another designed experiment, the selected façades are parallel to the baseline, the matching precision has a great improvement for façades, by an average of 22%. This fully proves our proposed algorithm that elimination of perspective distortion on rectified images can significantly improve the accuracy of dense matching.

  14. Page 1 Centrifugal distortion constants - - 115 triangular form ...

    Indian Academy of Sciences (India)

    Centrifugal distortion constants - - 115 triangular form (Ananthakrishnan et al 1972, 1973, 1976). In this context, setting. C equal to unit matrix is identical with the L matrix approximation technique developed by Muller (Alix et al 1975) and should hold good for nonhydride mole- cules as is implied in the observations of Strey ...

  15. View Angle Tilting Echo Planar Imaging for Distortion Correction

    Science.gov (United States)

    Ahn, Sinyeob; Hu, Xiaoping

    2011-01-01

    Geometric distortion caused by field inhomogeneity along the phase-encode (PE) direction is one of the most prominent artifacts due to a relatively low effective bandwidth along that direction in magnetic resonance echo planar imaging (EPI). This work describes a method for correcting in-plane image distortion along the PE direction using a view angle tilting (VAT) imaging technique in spin-echo EPI (SE-EPI). SE-EPI with VAT (SE-EPI-VAT) utilizes the addition of gradient blips along the slice-select (SS) direction, concurrently applied with the PE gradient blips, producing an additional phase. This phase effectively offsets an unwanted phase accumulation caused by field inhomogeneity, resulting in the removal of image distortion along the PE direction. The proposed method is simple and straightforward both in implementation and application with no scan time penalty. Therefore, it is readily applicable on commercial scanners without having any customized post-processing. The efficacy of the SE-EPI-VAT technique in the correction of image distortion is demonstrated in phantom and in vivo brain imaging. PMID:22213567

  16. Depression and Distortion in the Attribution of Causality

    Science.gov (United States)

    Rizley, Ross

    1978-01-01

    Two cognitive models of depression have attracted considerable attention recently: Seligman's (1975) learned helplessness model and Beck's (1967) cognitive schema approach. Describes each model and, in two studies, evaluates the assumption that depression is associated with systematic distortion in cognition regarding causal and controlling…

  17. Factors associated with body image distortion in Korean adolescents

    Directory of Open Access Journals (Sweden)

    Hyun MY

    2014-05-01

    Full Text Available Mi-Yeul Hyun,1 Young-Eun Jung,2 Moon-Doo Kim,2 Young-Sook Kwak,2 Sung-Chul Hong,3 Won-Myong Bahk,4 Bo-Hyun Yoon,5 Hye Won Yoon,6 Bora Yoo61College of Nursing, Jeju National University, Jeju, Korea; 2Department of Psychiatry, School of Medicine, Jeju National University, Jeju, Korea; 3Department of Preventive Medicine, School of Medicine, Jeju National University, Jeju, Korea; 4Department of Psychiatry, Yeouido St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea; 5Department of Psychiatry, Naju National Hospital, Naju, Korea; 6School of Medicine, Jeju National University, Jeju, KoreaPurpose: Body image incorporates cognitive and affective components as well as behaviors related to own body perception. This study evaluated the occurrence of body image distortion and its correlates in Korean adolescents.Methods: In a school-based cross-sectional survey, a total of 2,117 adolescents were recruited. They filled out self-completing questionnaires on body image distortion, eating attitudes, and behaviors (Eating Attitude Test-26 and related factors.Results: Body image distortions were found in 51.8 percent of adolescents. Univariate analyses showed that boys and older adolescents had higher rates of body image distortion. In the multivariate analyses, body image distortion was associated with high risk for eating disorders (odds ratio [OR] =1.69; 95% confidence interval [CI] 1.11–2.58; P=0.015 and being over weight (OR =33.27; 95% CI 15.51–71.35; P<0.001 or obese (OR =9.37; 95% CI 5.06–17.34; P<0.001.Conclusion: These results suggest that body image distortion is relatively common in Korean adolescents, which has implications for adolescents at risk of developing eating disorders.Keywords: body image distortion, high risk for eating disorders, Korean adolescent

  18. Rapid Prototyping

    Science.gov (United States)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  19. Distortions of subjective time perception within and across senses.

    Directory of Open Access Journals (Sweden)

    Virginie van Wassenhove

    Full Text Available BACKGROUND: The ability to estimate the passage of time is of fundamental importance for perceptual and cognitive processes. One experience of time is the perception of duration, which is not isomorphic to physical duration and can be distorted by a number of factors. Yet, the critical features generating these perceptual shifts in subjective duration are not understood. METHODOLOGY/FINDINGS: We used prospective duration judgments within and across sensory modalities to examine the effect of stimulus predictability and feature change on the perception of duration. First, we found robust distortions of perceived duration in auditory, visual and auditory-visual presentations despite the predictability of the feature changes in the stimuli. For example, a looming disc embedded in a series of steady discs led to time dilation, whereas a steady disc embedded in a series of looming discs led to time compression. Second, we addressed whether visual (auditory inputs could alter the perception of duration of auditory (visual inputs. When participants were presented with incongruent audio-visual stimuli, the perceived duration of auditory events could be shortened or lengthened by the presence of conflicting visual information; however, the perceived duration of visual events was seldom distorted by the presence of auditory information and was never perceived shorter than their actual durations. CONCLUSIONS/SIGNIFICANCE: These results support the existence of multisensory interactions in the perception of duration and, importantly, suggest that vision can modify auditory temporal perception in a pure timing task. Insofar as distortions in subjective duration can neither be accounted for by the unpredictability of an auditory, visual or auditory-visual event, we propose that it is the intrinsic features of the stimulus that critically affect subjective time distortions.

  20. Distortions of subjective time perception within and across senses.

    Science.gov (United States)

    van Wassenhove, Virginie; Buonomano, Dean V; Shimojo, Shinsuke; Shams, Ladan

    2008-01-16

    The ability to estimate the passage of time is of fundamental importance for perceptual and cognitive processes. One experience of time is the perception of duration, which is not isomorphic to physical duration and can be distorted by a number of factors. Yet, the critical features generating these perceptual shifts in subjective duration are not understood. We used prospective duration judgments within and across sensory modalities to examine the effect of stimulus predictability and feature change on the perception of duration. First, we found robust distortions of perceived duration in auditory, visual and auditory-visual presentations despite the predictability of the feature changes in the stimuli. For example, a looming disc embedded in a series of steady discs led to time dilation, whereas a steady disc embedded in a series of looming discs led to time compression. Second, we addressed whether visual (auditory) inputs could alter the perception of duration of auditory (visual) inputs. When participants were presented with incongruent audio-visual stimuli, the perceived duration of auditory events could be shortened or lengthened by the presence of conflicting visual information; however, the perceived duration of visual events was seldom distorted by the presence of auditory information and was never perceived shorter than their actual durations. These results support the existence of multisensory interactions in the perception of duration and, importantly, suggest that vision can modify auditory temporal perception in a pure timing task. Insofar as distortions in subjective duration can neither be accounted for by the unpredictability of an auditory, visual or auditory-visual event, we propose that it is the intrinsic features of the stimulus that critically affect subjective time distortions.

  1. Measuring signal generators theory & design

    CERN Document Server

    Rybin, Yuriy K

    2014-01-01

    The book brings together the following issues: Theory of deterministic, random and discrete signals reproducible in oscillatory systems of generators; Generation of periodic signals with a specified spectrum, harmonic distortion factor and random signals with specified probability density function and spectral density; Synthesis of oscillatory system structures; Analysis of oscillatory systems with non-linear elements and oscillation amplitude stabilization systems; It considers the conditions and criteria of steady-state modes in signal generators on active four-pole elements with unidirectional and bidirectional transmission of signals and on two-pole elements; analogues of Barkhausen criteria; Optimization of oscillatory system structures by harmonic distortion level, minimization of a frequency error and set-up time of the steady state mode; Theory of construction of random signal generators; Construction of discrete and digital signal generators; Practical design of main units of generators; Practical bl...

  2. Gene Genealogies Strongly Distorted by Weakly Interfering Mutations in Constant Environments

    Science.gov (United States)

    Seger, Jon; Smith, Wendy A.; Perry, Jarom J.; Hunn, Jessalynn; Kaliszewska, Zofia A.; Sala, Luciano La; Pozzi, Luciana; Rowntree, Victoria J.; Adler, Frederick R.

    2010-01-01

    Neutral nucleotide diversity does not scale with population size as expected, and this “paradox of variation” is especially severe for animal mitochondria. Adaptive selective sweeps are often proposed as a major cause, but a plausible alternative is selection against large numbers of weakly deleterious mutations subject to Hill–Robertson interference. The mitochondrial genealogies of several species of whale lice (Amphipoda: Cyamus) are consistently too short relative to neutral-theory expectations, and they are also distorted in shape (branch-length proportions) and topology (relative sister-clade sizes). This pattern is not easily explained by adaptive sweeps or demographic history, but it can be reproduced in models of interference among forward and back mutations at large numbers of sites on a nonrecombining chromosome. A coalescent simulation algorithm was used to study this model over a wide range of parameter values. The genealogical distortions are all maximized when the selection coefficients are of critical intermediate sizes, such that Muller's ratchet begins to turn. In this regime, linked neutral nucleotide diversity becomes nearly insensitive to N. Mutations of this size dominate the dynamics even if there are also large numbers of more strongly and more weakly selected sites in the genome. A genealogical perspective on Hill–Robertson interference leads directly to a generalized background-selection model in which the effective population size is progressively reduced going back in time from the present. PMID:19966069

  3. Large-scale selective sweep among Segregation Distorter chromosomes in African populations of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Daven C Presgraves

    2009-05-01

    Full Text Available Segregation Distorter (SD is a selfish, coadapted gene complex on chromosome 2 of Drosophila melanogaster that strongly distorts Mendelian transmission; heterozygous SD/SD(+ males sire almost exclusively SD-bearing progeny. Fifty years of genetic, molecular, and theory work have made SD one of the best-characterized meiotic drive systems, but surprisingly the details of its evolutionary origins and population dynamics remain unclear. Earlier analyses suggested that the SD system arose recently in the Mediterranean basin and then spread to a low, stable equilibrium frequency (1-5% in most natural populations worldwide. In this report, we show, first, that SD chromosomes occur in populations in sub-Saharan Africa, the ancestral range of D. melanogaster, at a similarly low frequency (approximately 2%, providing evidence for the robustness of its equilibrium frequency but raising doubts about the Mediterranean-origins hypothesis. Second, our genetic analyses reveal two kinds of SD chromosomes in Africa: inversion-free SD chromosomes with little or no transmission advantage; and an African-endemic inversion-bearing SD chromosome, SD-Mal, with a perfect transmission advantage. Third, our population genetic analyses show that SD-Mal chromosomes swept across the African continent very recently, causing linkage disequilibrium and an absence of variability over 39% of the length of the second chromosome. Thus, despite a seemingly stable equilibrium frequency, SD chromosomes continue to evolve, to compete with one another, or evade suppressors in the genome.

  4. Large-scale selective sweep among Segregation Distorter chromosomes in African populations of Drosophila melanogaster.

    Science.gov (United States)

    Presgraves, Daven C; Gérard, Pierre R; Cherukuri, Anjuli; Lyttle, Terrence W

    2009-05-01

    Segregation Distorter (SD) is a selfish, coadapted gene complex on chromosome 2 of Drosophila melanogaster that strongly distorts Mendelian transmission; heterozygous SD/SD(+) males sire almost exclusively SD-bearing progeny. Fifty years of genetic, molecular, and theory work have made SD one of the best-characterized meiotic drive systems, but surprisingly the details of its evolutionary origins and population dynamics remain unclear. Earlier analyses suggested that the SD system arose recently in the Mediterranean basin and then spread to a low, stable equilibrium frequency (1-5%) in most natural populations worldwide. In this report, we show, first, that SD chromosomes occur in populations in sub-Saharan Africa, the ancestral range of D. melanogaster, at a similarly low frequency (approximately 2%), providing evidence for the robustness of its equilibrium frequency but raising doubts about the Mediterranean-origins hypothesis. Second, our genetic analyses reveal two kinds of SD chromosomes in Africa: inversion-free SD chromosomes with little or no transmission advantage; and an African-endemic inversion-bearing SD chromosome, SD-Mal, with a perfect transmission advantage. Third, our population genetic analyses show that SD-Mal chromosomes swept across the African continent very recently, causing linkage disequilibrium and an absence of variability over 39% of the length of the second chromosome. Thus, despite a seemingly stable equilibrium frequency, SD chromosomes continue to evolve, to compete with one another, or evade suppressors in the genome.

  5. Heme Distortions in Sperm-Whale Carbonmonoxy Myoglobin: Correlations between Rotational Strengths and Heme Distortions in MD-Generated Structures

    Energy Technology Data Exchange (ETDEWEB)

    KIEFL,CHRISTOPH; SCREERAMA,NARASIMHA; LU,YI; QIU,YAN; SHELNUTT,JOHN A.; WOODY,ROBERT W.

    2000-07-13

    The authors have investigated the effects of heme rotational isomerism in sperm-whale carbonmonoxy myoglobin using computational techniques. Several molecular dynamics simulations have been performed for the two rotational isomers A and B, which are related by a 180{degree} rotation around the {alpha}-{gamma} axis of the heme, of sperm-whale carbonmonoxy myoglobin in water. Both neutron diffraction and NMR structures were used as starting structures. In the absence of an experimental structure, the structure of isomer B was generated by rotating the heme in the structure of isomer A. Distortions of the heme from planarity were characterized by normal coordinate structural decomposition and by the angle of twist of the pyrrole rings from the heme plane. The heme distortions of the neutron diffraction structure were conserved in the MD trajectories, but in the NMR-based trajectories, where the heme distortions are less well defined, they differ from the original heme deformations. The protein matrix induced similar distortions on the heroes in orientations A and B. The results suggest that the binding site prefers a particular macrocycle conformation, and a 180{degree} rotation of the heme does not significantly alter the protein's preference for this conformation. The intrinsic rotational strengths of the two Soret transitions, separated according to their polarization in the heme plane, show strong correlations with the ruf-deformation and the average twist angle of the pyrrole rings. The total rotational strength, which includes contributions from the chromophores in the protein, shows a weaker correlation with heme distortions.

  6. Distorted Tonotopic Coding of Temporal Envelope and Fine Structure with Noise-Induced Hearing Loss.

    Science.gov (United States)

    Henry, Kenneth S; Kale, Sushrut; Heinz, Michael G

    2016-02-17

    unclear. Here, we used innovative system-identification analyses of auditory nerve fiber responses to Gaussian noise to uncover pronounced distortions in coding of rapidly varying acoustic temporal fine structure and slower envelope cues following noise trauma. Because these distortions degrade and diminish the tonotopic representation of temporal acoustic features, a fundamental principle of auditory processing, the results represent a critical advancement in our understanding of the physiological bases of communication disorders. The detailed knowledge provided by this work will help guide the design of signal-processing strategies aimed at alleviating everyday communication problems for people with hearing loss. Copyright © 2016 the authors 0270-6474/16/362227-11$15.00/0.

  7. Experience of maltreatment as a child and acceptance of violence in adult intimate relationships: mediating effects of distortions in cognitive schemas.

    Science.gov (United States)

    Ponce, Allison N; Williams, Michelle K; Allen, George J

    2004-02-01

    Links exist between being subjected to maltreatment as a child and tendencies to accept violence as normative in adult relationships. Constructivist Self Development Theory suggests that such relationships may be affected by "cognitive disruptions" in "self" and "other" schemas. Mediating effects of distorted cognitive schemas on the association between history of child maltreatment and the acceptance of violence in intimate interpersonal relationships were investigated among 433 men and women. Outcomes indicated that individuals who reported childhood maltreatment were more likely to display distortions in their cognitive schemas and those individuals with disrupted schemas were more likely to accept relationship violence. Least-square multiple regression analyses revealed that distorted beliefs fully mediated the relationship between reporting childhood maltreatment and acceptance of violence, for both men and women. Subsidiary analyses suggested that this full mediation was replicated for schemas involving the self but not for schemas about others.

  8. Born distorted-wave approximation applied to the H+ + He collisions at intermediate and high energies

    Science.gov (United States)

    Rahmanian, M.; Fathi, R.; Shojaei, F.

    2017-11-01

    The single-charge transfer process in collision of protons with helium atoms in their ground states is investigated. The model utilizes the second-order three-body Born distorted-wave approximation (BDW-3B) with correct Coulomb boundary conditions to calculate the differential and total cross sections at intermediate and high energies. The role of the passive electrons and electron-electron correlations are studied by comparing our results and the BDW-4B calculations with the complete perturbation potential. The present results are also compared with other theories, and the Thomas scattering mechanism is investigated. The obtained results are also compared with the recent experimental measurements. For the prior differential cross sections, the comparisons show better agreement with the experiments at smaller scattering angles. The agreement between the total cross sections and the BDW-4B results as well as the experimental data is good at higher impact energies.

  9. Improved model of redshift-space distortions around voids: Application to quintessence dark energy

    Science.gov (United States)

    Achitouv, Ixandra

    2017-10-01

    Using cosmic voids to probe the growth rate of cosmic structure, and hence the nature of dark energy, is particularly interesting in the context of modified gravity theories that rely on the "screening mechanism." In this work we improve the modelling of redshift-space distortions around voids in the dark matter density field, and thus reduce systematic errors in the derivation of cosmological parameters. We also show how specific types of voids can be used to better probe the growth rate, using a flexible void finder. We apply our results to test for a "quintessence" type of dark energy vs. a Λ CDM model, and find a good agreement with the fiducial cosmology after implementing an analytical correction to the radial velocity profiles around voids. We additionally outline characteristic imprints of dark energy in the dark matter velocity distributions around voids.

  10. A New Method of Designing Circularly Symmetric Shaped Dual Reflector Antennas Using Distorted Conics

    Directory of Open Access Journals (Sweden)

    Mohammad Asif Zaman

    2014-01-01

    Full Text Available A new method of designing circularly symmetric shaped dual reflector antennas using distorted conics is presented. The surface of the shaped subreflector is expressed using a new set of equations employing differential geometry. The proposed equations require only a small number of parameters to accurately describe practical shaped subreflector surfaces. A geometrical optics (GO based method is used to synthesize the shaped main reflector surface corresponding to the shaped subreflector. Using the proposed method, a shaped Cassegrain dual reflector system is designed. The field scattered from the subreflector is calculated using uniform geometrical theory of diffraction (UTD. Finally, a numerical example is provided showing how a shaped subreflector produces more uniform illumination over the main reflector aperture compared to an unshaped subreflector.

  11. Distortions and gender-related differences in the perception of mechanical engineering in high school students.

    Science.gov (United States)

    Ferrando Piera, Pere Joan; Gutiérrez-Colón Plana, Mar; Paleo Cageao, Paloma; de la Flor López, Silvia; Ferrando Piera, Francesc

    2013-01-01

    The reason for this study was the low interest that high school students, particularly females, show for the subject of mechanical engineering (ME). We assumed that this problem was partly due to: (a) lack of understanding of the tasks involved in ME, and (b) a distorted and negative perception of the professional environment and working conditions. To assess these two assumptions, two measurement instruments (tasks and perceptions) were developed and administered in a sample of 496 high school students. A multiple-group design was used and data was analyzed by using an extended item response theory model. In general terms, the results agreed with our expectations. However, no significant gender differences were found. The implications of the results for future improvements are discussed.

  12. Distortional buckling modes of semi-discretized thin-walled columns

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Jönsson, Jeppe

    2012-01-01

    stress equations for simply supported columns with constrained transverse displacements at the end sections and a constant axial initial stress. Based on the known boundary conditions the reduced order differential equations are solved by using the trigonometric solution functions and solving the related......This paper presents distorting buckling solutions for semi-discretized thin-walled columns using the coupled differential equations of a generalized beam theory (GBT). In two related papers recently published by the authors a novel semi-discretization approach to GBT has been presented. The cross...... section is discretized and analytical solutions are sought for the variation along the beam. With this new approach the general GBT equations for identification of a full set of deformation modes corresponding to both homogeneous and non-homogenous equations are formulated and solved. Thereby giving...

  13. CMB spectral distortions in generic two-field models

    Science.gov (United States)

    Kainulainen, Kimmo; Leskinen, Juuso; Nurmi, Sami; Takahashi, Tomo

    2017-11-01

    We investigate the CMB μ distortion in models where two uncorrelated sources contribute to primordial perturbations. We parameterise each source by an amplitude, tilt, running and running of the running. We perform a detailed analysis of the distribution signal as function of the model parameters, highlighting the differences compared to single-source models. As a specific example, we also investigate the mixed inflaton-curvaton scenario. We find that the μ distortion could efficiently break degeneracies of curvaton parameters especially when combined with future sensitivity of probing the tensor-to-scalar ratio r. For example, assuming bounds μ < 0.5 × 10‑8 and r<0.01, the curvaton contribution should either vanish or the curvaton should dominate primordial perturbations and its slow-roll parameter ηχ is constrained to the interval ‑0.007 < ηχ< 0.045.

  14. Mapping flow distortion on oceanographic platforms using computational fluid dynamics

    Directory of Open Access Journals (Sweden)

    N. O'Sullivan

    2013-10-01

    Full Text Available Wind speed measurements over the ocean on ships or buoys are affected by flow distortion from the platform and by the anemometer itself. This can lead to errors in direct measurements and the derived parametrisations. Here we computational fluid dynamics (CFD to simulate the errors in wind speed measurements caused by flow distortion on the RV Celtic Explorer. Numerical measurements were obtained from the finite-volume CFD code OpenFOAM, which was used to simulate the velocity fields. This was done over a range of orientations in the test domain from −60 to +60° in increments of 10°. The simulation was also set up for a range of velocities, ranging from 5 to 25 m s−1 in increments of 0.5 m s−1. The numerical analysis showed close agreement to experimental measurements.

  15. Predicting Harmonic Distortion of Multiple Converters in a Power System

    Directory of Open Access Journals (Sweden)

    P. M. Ivry

    2017-01-01

    Full Text Available Various uncertainties arise in the operation and management of power systems containing Renewable Energy Sources (RES that affect the systems power quality. These uncertainties may arise due to system parameter changes or design parameter choice. In this work, the impact of uncertainties on the prediction of harmonics in a power system containing multiple Voltage Source Converters (VSCs is investigated. The study focuses on the prediction of harmonic distortion level in multiple VSCs when some system or design parameters are only known within certain constraints. The Univariate Dimension Reduction (UDR method was utilized in this study as an efficient predictive tool for the level of harmonic distortion of the VSCs measured at the Point of Common Coupling (PCC to the grid. Two case studies were considered and the UDR technique was also experimentally validated. The obtained results were compared with that of the Monte Carlo Simulation (MCS results.

  16. Sleep Wrinkles: Facial Aging and Facial Distortion During Sleep.

    Science.gov (United States)

    Anson, Goesel; Kane, Michael A C; Lambros, Val

    2016-09-01

    Wrinkles are just one indicator of facial aging, but an indicator that is of prime importance in our world of facial aesthetics. Wrinkles occur where fault lines develop in aging skin. Those fault lines may be due to skin distortion resulting from facial expression or may be due to skin distortion from mechanical compression during sleep. Expression wrinkles and sleep wrinkles differ in etiology, location, and anatomical pattern. Compression, shear, and stress forces act on the face in lateral or prone sleep positions. We review the literature relating to the development of wrinkles and the biomechanical changes that occur in response to intrinsic and extrinsic influences. We explore the possibility that compression during sleep not only results in wrinkles but may also contribute to facial skin expansion. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  17. Local distortion around the guest ion in perovskite oxides

    Science.gov (United States)

    Akama, Shota; Kobayashi, Wataru; Niwa, Hideharu; Uchiyama, Tomoki; Moritomo, Yutaka

    2017-05-01

    In transition metal (M) oxides, partial substitution of guest (M g) for host (M h) elements causes local distortion via the difference in the ionic radius (r). Here, we systematically investigated the local structures in the pure (x = 0.0) and mixed (x = 0.1) perovskite oxides, \\text{La}M1 - x\\text{h}Mx\\text{g}\\text{O}3, by means of extended X-ray absorption fine structure (EXAFS) analysis. We found that the local distortion [ɛ \\equiv \\sqrt{\\smash{(1/3)Σ x,y,z(Δ d\\text{adj}\\text{h})2}\\mathstrut} , where Δ d\\text{adj}\\text{h} is the variation in the adjacent M h-O bond length] in a mixed compound, was smaller than that in the virtual compound, in which the M g-O bond length had an ideal value. This empirical relation is useful for designing a functional material by partial substitution.

  18. In situ visualization of thermal distortions of synchrotron radiation optics

    Science.gov (United States)

    Revesz, P.; Kazimirov, A.; Bazarov, I.

    2007-06-01

    We have developed a new in situ method to measure heating-induced distortions of the surface of the first monochromator crystal exposed to high-power white synchrotron radiation beam. The method is based on recording the image of a stationary grid of dots captured by a CCD camera as reflected from the surface of a crystal with and without a heat load. The three-dimensional surface profile (heat bump) is then reconstructed from the distortions of the original pattern. In experiments performed at the CHESS A2 wiggler beam line we measured the heat bumps with the heights of up to 600 nm produced by a wiggler beam with total power in the range of 15-60 W incident on the (1 1 1) Si crystal at various angles between 3° and 15°.

  19. Modelling Thermoelastic Distortion of Optics Using Elastodynamic Reciprocity

    CERN Document Server

    King, Eleanor; Veitch, Peter; Levin, Yuri

    2015-01-01

    Thermoelastic distortion resulting from optical absorption by transmissive and reflective optics can cause unacceptable changes in optical systems that employ high power beams. In advanced-generation laser-interferometric gravitational wave detectors for example, optical absorption is expected to result in wavefront distortions that would compromise the sensitivity of the detector; thus necessitating the use of adaptive thermal compensation. Unfortunately, these systems have long thermal time constants and so predictive feed-forward control systems could be required - but the finite-element analysis is computationally expensive. We describe here the use of the Betti-Maxwell elastodynamic reciprocity theorem to calculate the response of linear elastic bodies (optics) to heating that has arbitrary spatial distribution. We demonstrate using a simple example, that it can yield accurate results in computational times that are significantly less than those required for finite-element analyses.

  20. Distortional Mechanics of Thin-Walled Structural Elements

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim

    In several industries such as civil, mechanical, and aerospace, thin-walled structures are often used due to the high strength and effective use of the materials. Because of the increased consumption there has been increasing focus on optimizing and more detailed calculations. However, finely...... eigenmodes and may be used in the automatic meshing of approximate distortional beam elements. The magnitude of the eigenvalues thus also gives the natural ordering of the modes. The results are compared to results found using other computational methods taking distortion of the cross section into account...... provides reasonable results with a very small computational cost making it a good alternative to the classical FE calculations and other available methods....

  1. Distorting the metric fabric of the cognitive map.

    Science.gov (United States)

    Jeffery, Kate J

    2015-06-01

    Grid cells are neurons whose regularly spaced firing fields form apparently symmetric arrays, or grids, that are thought to collectively provide an environment-independent metric framework for the brain's cognitive map of space. However, two recent studies show that grids are naturally distorted, revealing greater local environment-specific effects than previously recognized. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

  2. Cognitive Distortions Among Sexual Offenders Against Women in Japan.

    Science.gov (United States)

    Hazama, Kyoko; Katsuta, Satoshi

    2016-09-15

    Research in Western countries has indicated that the cognitive distortions of sexual offenders play an etiological and maintenance role in offending. The present study examines whether the cognitive distortions hypothesized by previous Western studies can be found in Japanese sexual offenders against women. This study used the questionnaire administered by probation officers in the special cognitive-behavioral treatment programs for sexual offenders, which have been implemented since 2006 in Japan. Participants in the offender group were 80 Japanese male probationers and parolees (more than 19 years old, M age = 34.6, SD = 8.8) convicted of rape (n = 39) or indecent assault (n = 41). All of them attended special treatment programs at probation offices. The non-offender comparison group consisted of 95 Japanese male probation officers and police officers (M age = 35.5, SD = 11.4). A factor analysis of the questionnaire responses extracted three factors: Blaming the Victim, Minimization, and Avoidance of Responsibility. The data analyses showed that sexual offenders scored significantly higher than non-offender participants on the three subscales. No significant differences were found among four sexual offender groups classified as rapists or indecent assaulters and with or without previous convictions for sexual offenses. In conclusion, the results of this study indicate that rapists and indecent assaulters placed on probation or parole in Japan hold cognitive distortions concerning sexual assaults against women than the control group of probation and police officers. The findings of this study also suggest that cognitive distortions exhibited by sexual offenders against women transcend cultural divides. © The Author(s) 2016.

  3. Geometric and dynamic distortions in anisotropic galaxy clustering

    Science.gov (United States)

    Blazek, Jonathan; Seljak, Uroš; Vlah, Zvonimir; Okumura, Teppei

    2014-04-01

    We examine the signature of dynamic (redshift-space) distortions and geometric distortions (including the Alcock-Paczynski effect) in the context of the galaxy power spectrum measured in upcoming galaxy redshift surveys. Information comes from both the baryon acoustic oscillation (BAO) feature and the broadband power spectrum shape. Accurate modeling is required to extract this information without systematically biasing the result. We consider an analytic model for the power spectrum of dark matter halos in redshift space, based on the distribution function expansion, and compare with halo clustering measured in N-body simulations. We forecast that the distribution function model is sufficiently accurate to allow the inclusion of broadband information on scales down to k ~ 0.2h Mpc-1, with somewhat better accuracy for higher bias halos. Compared with a BAO-only analysis with reconstruction, including broadband shape information can improve unbiased constraints on distance measures H(z) and DA(z) by ~ 30% and 20%, respectively, for a galaxy sample similar to the DESI luminous red galaxies. The gains in precision are larger in the absence of BAO reconstruction. Furthermore, including broadband shape information allows the measurement of structure growth, through redshift-space distortions. For the same galaxy sample, the distribution function model is able to constrain fσ8 to ~ 2%, when simultaneously fitting for H(z) and DA(z). We discuss techniques to optimize the analysis of the power spectrum, including removing modes near the line-of-sight that are particularly challenging to model, and whether these approaches can improve parameter constraints. We find that such techniques are unlikely to significantly improve constraints on geometry, although they may allow higher precision measurements of redshift-space distortions.

  4. Regulation of Entry and the Distortion of Industrial Organization

    OpenAIRE

    Raymond Fisman; Virginia Sarria-Allende

    2004-01-01

    We study the distortions to industrial organization caused by entry regulation. We take advantage of heterogeneity across industries in their natural barriers and growth opportunities to examine whether some industries are differentially affected by country-level entry regulation. In industries with high natural entry barriers, entry regulation has little impact on the quantity and average size of firms in an industry. By contrast, in industries with low natural entry barriers, countries with...

  5. India?s Distorted Sex Ratio: Dire Consequences for Girls

    OpenAIRE

    Roberts, Lisa R.; Montgomery, Susanne B.

    2016-01-01

    Female gender discrimination related to cultural preference for males is a common global problem, especially in Asian countries. Numerous laws intended to prevent discrimination on the basis of gender have been passed in India, yet the distorted female-to-male sex ratio seems to show worsening tendencies. Using detailed, two-year longitudinal chart abstraction data about delivery records of a private mission hospital in rural India, we explored if hospital birth ratio data differed in compari...

  6. QRS distortion increased risk re-occurrence acute coronary events

    Directory of Open Access Journals (Sweden)

    Manoefris Kasim

    2007-12-01

    Full Text Available Nearly 50% of patients suffering inferior myocardial infarction will have complications or distinguishing features associated with an increased mortality. This study aimed to identify dominant risk factors related to re-occurrence of acute coronary events in patients with inferior myocardial infarction. This historical cohort included patients with inferior myocardial infarction who received fibrinolytic therapy at emergency department of National Cardiovascular Center Harapan Kita, Jakarta during 2001 to 2004 and was followed-up for two years. Patients with previous myocardial infarction, left bundle branch block, ventricular rhythm, and ventricular pacing were excluded. QRS distortion is ratio between J-point and R wave more than 50% at 2 or more inferior leads. Re-occurrence of acute coronary events is incident of myocardial infarction and unstable angina pectoris. Of 181 subjects with inferior AMI, there were 21 (11.6% incidents of acute coronary event. Those who had positive than negative QRS distortion had almost three-fold increased risk for re-occurrence of acute coronary events [adjusted relative risk (RRa 2.88; 95% confidence interval (CI = 1.05 – 7.90]. In term of TIMI risk score, those with higher than lower risk score had 6.7 times higher risk to be re-occurrence of acute coronary events (RRa = 6.66; 95% CI = 1.94 – 22.92. However, those who had than did not have successful fibrinolysis had 57% lower risk to be re-occurrence of acute coronary event (RRa = 0.43; 95% CI = 0.18 – 1.05; P = 0.065. Re-occurrence acute coronary events were related to QRS distortion, TIMI risk score, and successful fibrinolysis. (Med J Indones 2007; 16:240-4 Keywords: QRS distortion, fibrinolysis, inferior myocardial infarction

  7. Measuring Loudspeaker Distortion and Room Reverberation Time Using a Speakerphone

    OpenAIRE

    Wilhelmsson, Viktor

    2016-01-01

    This master thesis project was carried out during the spring semester of 2016 at the company Limes Audio. The company specializes in making software, electronics, industrial design and mechanics with the aim to improve audio quality in loudspeaking communication systems. The performance of audio conferencing systems may degrade if there are distortions, or if the acoustical properties of the room are unfavorable. To ensure that the system works optimally, any unwanted effects must first be id...

  8. Distortion risk measures for sums of dependent losses | Brahimi ...

    African Journals Online (AJOL)

    ... of losses and possible correlations between risk components. Resume. Nous discutons deux approches distinctes, de distortion des mesures de risque de la somme de variables al´eatoires d´ependantes, qui conservent la propri´et´e de coh´erence. La premi`ere, bas´ee sur les esp´erances distordues, agit sur la fonction ...

  9. An EM algorithm for mapping segregation distortion loci

    Directory of Open Access Journals (Sweden)

    Zhang Yuan-Ming

    2007-11-01

    Full Text Available Abstract Background Chromosomal region that causes distorted segregation ratios is referred to as segregation distortion locus (SDL. The distortion is caused either by differential representation of SDL genotypes in gametes before fertilization or by viability differences of SDL genotypes after fertilization but before genotype scoring. In both cases, observable phenotypes are distorted for marker loci in the chromosomal region close to the SDL. Under the quantitative genetics model for viability selection by proposing a continuous liability controlling the viability of individual, a simplex algorithm has been used to search for the solution in SDL mapping. However, they did not consider the effects of SDL on the construction of linkage maps. Results We proposed a multipoint maximum-likelihood method to estimate the position and the effects of SDL under the liability model together with both selection coefficients of marker genotypes and recombination fractions. The method was implemented via an expectation and maximization (EM algorithm. The superiority of the method proposed under the liability model over the previous methods was verified by a series of Monte Carlo simulation experiments, together with a working example derived from the MAPMAKER/QTL software. Conclusion Our results suggested that the new method can serve as a powerful alternative to existing methods for SDL mapping. Under the liability model, the new method can simultaneously estimate the position and the effects of SDL as well as the recombinant fractions between adjacent markers, and also be used to probe into the genetic mechanism for the bias of uncorrected map distance and to elucidate the relationship between the viability selection and genetic linkage.

  10. An EM algorithm for mapping segregation distortion loci.

    Science.gov (United States)

    Zhu, Chengsong; Zhang, Yuan-Ming

    2007-11-29

    Chromosomal region that causes distorted segregation ratios is referred to as segregation distortion locus (SDL). The distortion is caused either by differential representation of SDL genotypes in gametes before fertilization or by viability differences of SDL genotypes after fertilization but before genotype scoring. In both cases, observable phenotypes are distorted for marker loci in the chromosomal region close to the SDL. Under the quantitative genetics model for viability selection by proposing a continuous liability controlling the viability of individual, a simplex algorithm has been used to search for the solution in SDL mapping. However, they did not consider the effects of SDL on the construction of linkage maps. We proposed a multipoint maximum-likelihood method to estimate the position and the effects of SDL under the liability model together with both selection coefficients of marker genotypes and recombination fractions. The method was implemented via an expectation and maximization (EM) algorithm. The superiority of the method proposed under the liability model over the previous methods was verified by a series of Monte Carlo simulation experiments, together with a working example derived from the MAPMAKER/QTL software. Our results suggested that the new method can serve as a powerful alternative to existing methods for SDL mapping. Under the liability model, the new method can simultaneously estimate the position and the effects of SDL as well as the recombinant fractions between adjacent markers, and also be used to probe into the genetic mechanism for the bias of uncorrected map distance and to elucidate the relationship between the viability selection and genetic linkage.

  11. Psychoanalytic reflections on a particular form of language distortion.

    Science.gov (United States)

    Spero, M H

    1990-01-01

    A female obsessive patient communicated with her sister via a distortion of the Hebrew language, in which she masculinized the feminine gender second person pronoun and certain nouns. This treatment of words is analyzed in terms ranging from the concrete to the metaphoric uses of language. Lacan's emphasis on the meaning of the word is explored and is seen as an amplification rather than a replacement of the object relations approach to language and metaphor.

  12. Development strategy, viability, and economic distortions in developing countries

    OpenAIRE

    Lin, Justin Yifu; Li, Feiyue

    2009-01-01

    This paper presents a three-sector static model to explore the rationale for a series of institutional distortions in developing countries. The authors argue that, after World War II, motivated by a belief in the development of state-of-the-art industries as a means for nation building, the majority of developing country governments attempted to accelerate the growth of advanced capital-in...

  13. Damage to insula abolishes cognitive distortions during simulated gambling.

    Science.gov (United States)

    Clark, Luke; Studer, Bettina; Bruss, Joel; Tranel, Daniel; Bechara, Antoine

    2014-04-22

    Gambling is a naturalistic example of risky decision-making. During gambling, players typically display an array of cognitive biases that create a distorted expectancy of winning. This study investigated brain regions underpinning gambling-related cognitive distortions, contrasting patients with focal brain lesions to the ventromedial prefrontal cortex (vmPFC), insula, or amygdala ("target patients") against healthy comparison participants and lesion comparison patients (i.e., with lesions that spare the target regions). A slot machine task was used to deliver near-miss outcomes (i.e., nonwins that fall spatially close to a jackpot), and a roulette game was used to examine the gambler's fallacy (color decisions following outcome runs). Comparison groups displayed a heightened motivation to play following near misses (compared with full misses), and manifested a classic gambler's fallacy effect. Both effects were also observed in patients with vmPFC and amygdala damage, but were absent in patients with insula damage. Our findings indicate that the distorted cognitive processing of near-miss outcomes and event sequences may be ordinarily supported by the recruitment of the insula. Interventions to reduce insula reactivity could show promise in the treatment of disordered gambling.

  14. Neutrino Spectrum Distortion Due to Oscillations and its BBN Effect

    CERN Document Server

    Kirilova, Daniela P

    2004-01-01

    We study the distortion of electron neutrino energy spectrum due to oscillations with the sterile neutrino nu_e nu_s, and its influence on BBN for different initial populations of the sterile state delta N_s at the onset of oscillations. Only the case of an initially empty sterile state was studied in previous publications. We obtain the primordial abundance of He-4 in models with electron-sterile neutrino oscillations for all possible delta N_s: 0 <= delta N_s <= 1 and for the model of oscillations, effective after electron neutrino decoupling, for which the spectrum distortion effects on the neutron-proton transitions are the strongest. It is found that the spectrum distortion effect may be the dominant one not only for small delta N_s, but also for big initial population of the sterile state. It was found that in the resonant case it plays a considerable role even for very big delta N_s ~ 0.8. We discuss cosmological constraints on neutrino mixing for small delta N_s.

  15. Gear distortion analysis due to heat treatment process

    Science.gov (United States)

    Guterres, Natalino F. D. S.; Rusnaldy, Widodo, Achmad

    2017-01-01

    One way to extend the life time of the gear is minimizing the distortion during the manufacturing process. One of the most important processes in manufacturing to produce gears is heat treatment process. The purpose of this study is to analyze the distortion of the gear after heat treatment process. The material of gear is AISI 1045, and it was designed with the module (m) 1.75, and a number of teeth (z) 29. Gear was heat-treated in the furnace at a temperature of 800°C, holding time of 30 minutes, and then quenched in water. Furthermore, surface hardening process was also performed on gear teeth at a temperature of 820°C and holding time of 35 seconds and the similar procedure of analysis was conducted. The hardness of gear after heat treatment average 63.2 HRC and the teeth surface hardness after gear to induction hardening was 64.9 HRC at the case depth 1 mm. The microstructure of tested gear are martensitic and pearlite. The highest distortion on tooth thickness to upper than 0.063 can cause high precision at the tooth contact is not appropriate. Besides the shrinkage of tooth thickness will also affect to contact angle because the size of gear tolerance was not standardized.

  16. Applying image quality in cell phone cameras: lens distortion

    Science.gov (United States)

    Baxter, Donald; Goma, Sergio R.; Aleksic, Milivoje

    2009-01-01

    This paper describes the framework used in one of the pilot studies run under the I3A CPIQ initiative to quantify overall image quality in cell-phone cameras. The framework is based on a multivariate formalism which tries to predict overall image quality from individual image quality attributes and was validated in a CPIQ pilot program. The pilot study focuses on image quality distortions introduced in the optical path of a cell-phone camera, which may or may not be corrected in the image processing path. The assumption is that the captured image used is JPEG compressed and the cellphone camera is set to 'auto' mode. As the used framework requires that the individual attributes to be relatively perceptually orthogonal, in the pilot study, the attributes used are lens geometric distortion (LGD) and lateral chromatic aberrations (LCA). The goal of this paper is to present the framework of this pilot project starting with the definition of the individual attributes, up to their quantification in JNDs of quality, a requirement of the multivariate formalism, therefore both objective and subjective evaluations were used. A major distinction in the objective part from the 'DSC imaging world' is that the LCA/LGD distortions found in cell-phone cameras, rarely exhibit radial behavior, therefore a radial mapping/modeling cannot be used in this case.

  17. Probing correlations of early magnetic fields using mu-distortion

    DEFF Research Database (Denmark)

    Ganc, Jonathan; Sloth, Martin Snoager

    2014-01-01

    The damping of a non-uniform magnetic field between the redshifts of about $10^4$ and $10^6$ injects energy into the photon-baryon plasma and causes the CMB to deviate from a perfect blackbody spectrum, producing a so-called $\\mu$-distortion. We can calculate the correlation $\\langle\\mu T......\\rangle$ of this distortion with the temperature anisotropy $T$ of the CMB to search for a correlation $\\langle B^2\\zeta\\rangle$ between the magnetic field $B$ and the curvature perturbation $\\zeta$; knowing the $\\langle B^2\\zeta\\rangle$ correlation would help us distinguish between different models of magnetogenesis. Since......_{\\text{NL}}$). We find that a PIXIE-like CMB experiments has a signal to noise $S/N\\approx 1.0 \\times b_{\\text{NL}} (\\tilde B_\\mu/10\\text{ nG})^2$, where $\\tilde B_\\mu$ is the magnetic field's strength on $\\mu$-distortion scales normalized to today's redshift; thus, a 10 nG field would be detectable with $b...

  18. Wave theory of information

    CERN Document Server

    Franceschetti, Massimo

    2017-01-01

    Understand the relationship between information theory and the physics of wave propagation with this expert guide. Balancing fundamental theory with engineering applications, it describes the mechanism and limits for the representation and communication of information using electromagnetic waves. Information-theoretic laws relating functional approximation and quantum uncertainty principles to entropy, capacity, mutual information, rate distortion, and degrees of freedom of band-limited radiation are derived and explained. Both stochastic and deterministic approaches are explored, and applications for sensing and signal reconstruction, wireless communication, and networks of multiple transmitters and receivers are reviewed. With end-of-chapter exercises and suggestions for further reading enabling in-depth understanding of key concepts, it is the ideal resource for researchers and graduate students in electrical engineering, physics and applied mathematics looking for a fresh perspective on classical informat...

  19. Automatic estimation and correction of anisotropic magnification distortion in electron microscopes.

    Science.gov (United States)

    Grant, Timothy; Grigorieff, Nikolaus

    2015-11-01

    We demonstrate a significant anisotropic magnification distortion, found on an FEI Titan Krios microscope and affecting magnifications commonly used for data acquisition on a Gatan K2 Summit detector. We describe a program (mag_distortion_estimate) to automatically estimate anisotropic magnification distortion from a set of images of a standard gold shadowed diffraction grating. We also describe a program (mag_distortion_correct) to correct for the estimated distortion in collected images. We demonstrate that the distortion present on the Titan Krios microscope limits the resolution of a set of rotavirus VP6 images to ∼7 Å, which increases to ∼3 Å following estimation and correction of the distortion. We also use a 70S ribosome sample to demonstrate that in addition to affecting resolution, magnification distortion can also interfere with the classification of heterogeneous data. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Distortion analysis on binary representation of minutiae based fingerprint matching for match-on-card

    CSIR Research Space (South Africa)

    Mlambo, CS

    2016-12-01

    Full Text Available , distortion is a major challenge in binary representation of minutiae points that affect the accuracy in fingerprint matching. Therefore this paper includes the methods used to deal with fingerprint distortion while representing minutiae points as binary...

  1. Worst case estimate of mismatch induced distortion in complementary CMOS current mirrors

    DEFF Research Database (Denmark)

    Bruun, Erik

    1998-01-01

    Mismatching between the MOS transistors in a current mirror causes harmonic distortion. In a complementary class AB current mirror, mismatching of threshold voltages, geometries and transconductance parameters causes a distortion which cannot be eliminated by circuit techniques but which can...

  2. Document forgery detection using distortion mutation of geometric parameters in characters

    Science.gov (United States)

    Shang, Shize; Kong, Xiangwei; You, Xingang

    2015-03-01

    Tampering related to document forgeries is often accomplished by copy-pasting or add-printing. These tampering methods introduce character distortion mutation in documents. We present a method of exposing document forgeries using distortion mutation of geometric parameters. We estimate distortion parameters, which consist of translation and rotation distortions, through image matching for each character. Detection of tampered characters with distortion mutation occurs based on a distortion probability, which is calculated from character distortion parameters. The introduction of a visualized probability map describes the degree of distortion mutation for a full page. The proposed method exposes the forgeries based on individual characters and applies to English and Chinese document examinations. Experimental results demonstrate the effectiveness of our method on low JPEG compression quality and low resolution.

  3. A meta-analysis on cognitive distortions and externalizing problem behavior : associations, moderators, and treatment effectiveness

    NARCIS (Netherlands)

    Helmond, P.; Overbeek, G.; Brugman, D.; Gibbs, J.C.

    2015-01-01

    Cognitive distortions are an important focus in many investigations and treatments of externalizing problem behavior, such as antisocial, delinquent, and aggressive behavior. Yet the overall strength of the association between cognitive distortions and externalizing behavior is unknown. Furthermore,

  4. H∞ Robust Current Control for DFIG Based Wind Turbine subject to Grid Voltage Distortions

    OpenAIRE

    Wang, Yun; Wu, Qiuwei; Gong, Wenming; Gryning, Mikkel Peter Sidoroff

    2016-01-01

    This paper proposes an H∞ robust current controller for doubly fed induction generator (DFIG) based wind turbines (WTs) subject to grid voltage distortions. The controller is to mitigate the impact of the grid voltage distortions on rotor currents with DFIG parameter perturbation. The grid voltage distortions considered include asymmetric voltage dips and grid background harmonics. An uncertain DFIG model is developed with uncertain factors originating from distorted stator voltage, and chang...

  5. Cognitive Distortions as Mediators between Life Stress and Depression in Adolescents.

    Science.gov (United States)

    Deal, Saundra L.; Williams, John E.

    1988-01-01

    Administered measures of cognitive distortion, life stress, and depressive tendencies to 103 high school students. Findings were consistent with predictions that measures of cognitive distortion would be better predictors of depressive tendencies than were measures of life stress; cognitive distortions would affect perceived stressfulness of life…

  6. Body Image Dissatisfaction and Distortion, Steroid Use, and Sex Differences in College Age Bodybuilders.

    Science.gov (United States)

    Peters, Mark Anthony; Phelps, LeAddelle

    2001-01-01

    Compares college age bodybuilders by sex and steroid intake on two variables: body image dissatisfaction and body image distortion. Results reveal only a significant effect for gender on body distortion. No steroid-use differences were apparent for either body image dissatisfaction or body image distortion. Analyses indicate that female…

  7. Dewey's Theory of Moral (and Political) Deliberation Unfiltered

    Science.gov (United States)

    Ralston, Shane J.

    2010-01-01

    In this paper, I argue that many recent interpretations of John Dewey's vision of democracy distort that vision by filtering it through the prism of contemporary deliberative democratic theories. An earlier attempt to defend Dewey's theory of moral deliberation is instructive for understanding the nature and function of this filter. In James…

  8. Waltz's Theory of Theory

    DEFF Research Database (Denmark)

    Wæver, Ole

    2009-01-01

    Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism and refle......Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism...... and reflectivism. Yet, ironically, there has been little attention to Waltz's very explicit and original arguments about the nature of theory. This article explores and explicates Waltz's theory of theory. Central attention is paid to his definition of theory as ‘a picture, mentally formed' and to the radical anti......-empiricism and anti-positivism of his position. Followers and critics alike have treated Waltzian neorealism as if it was at bottom a formal proposition about cause-effect relations. The extreme case of Waltz being so victorious in the discipline, and yet being consistently mis-interpreted on the question of theory...

  9. Control theory

    CERN Document Server

    Simrock, S

    2008-01-01

    In engineering and mathematics, control theory deals with the behaviour of dynamical systems. The desired output of a system is called the reference. When one or more output variables of a system need to follow a certain reference over time, a controller manipulates the inputs to a system to obtain the desired effect on the output of the system. Rapid advances in digital system technology have radically altered the control design options. It has become routinely practicable to design very complicated digital controllers and to carry out the extensive calculations required for their design. These advances in implementation and design capability can be obtained at low cost because of the widespread availability of inexpensive and powerful digital processing platforms and high-speed analog IO devices.

  10. Archetypes of Destruction: Notes on the Impact of Distorted Management Theory on Education Communities

    Science.gov (United States)

    Chater, Mark

    2005-01-01

    Management's current self-consciousness as a young but privileged discipline situated among other fields of knowledge is critically interpreted. The praxis of management is found to lack characteristics of stability and self-reflection belonging to other, older academic disciplines. The use of the concept of "gods of mismanagement" is an…

  11. Human Capital Theory and Internal Migration: Do Average Outcomes Distort Our View of Migrant Motives?

    Science.gov (United States)

    Korpi, Martin; Clark, William A W

    2017-05-01

    By modelling the distribution of percentage income gains for movers in Sweden, using multinomial logistic regression, this paper shows that those receiving large pecuniary returns from migration are primarily those moving to the larger metropolitan areas and those with higher education, and that there is much more variability in income gains than what is often assumed in models of average gains to migration. This suggests that human capital models of internal migration often overemphasize the job and income motive for moving, and fail to explore where and when human capital motivated migration occurs.

  12. The relationship between religious orientation, and gender with a cognitive distortion.

    Science.gov (United States)

    Amirsardari, Leili; Azari, Shafie; Esmali Kooraneh, Ahmad

    2014-01-01

    The objective of this study was to determine the relationship between religious orientation (intrinsic-external) and cognitive distortions. General design of this study considered as a descriptive and correlational method. Universal population in this research consist all students of the Urmia Azad University, which were studying during 2012 and 2013 (n = 250). All respondents filled the Alports religious and cognitive distortions questionnaires. The answers were analyzed with step by step regression and correlation method. The research showed a significant relationship between the religious orientation and cognitive distortions (p cognitive distortions and individuals with intrinsic religious orientation have less cognitive distortion.

  13. On the relationship between perceptual impact of source and channel distortions in video sequences

    DEFF Research Database (Denmark)

    Korhonen, Jari; Reiter, Ulrich; You, Junyong

    2010-01-01

    It is known that peak signal-to-noise ratio (PSNR) can be used for assessing the relative qualities of distorted video sequences meaningfully only if the compared sequences contain similar types of distortions. In this paper, we propose a model for rough assessment of the bias in PSNR results, when...... video sequences with both channel and source distortion are compared against video sequences with source distortion only. The proposed method can be used to compare the relative perceptual quality levels of video sequences with different distortion types more reliably than using plain PSNR....

  14. Harmonic Distortion of Rectifier Topologies for Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Hansen, Steffan

    and to find reasonable (economical) solutions if the harmonic distortion is exceeding acceptable levels. To define some acceptable harmonic levels, the international standards IEC 61000-2-2, IEC 61000-2-4, the harmonic limiting standards EN 61000-3-2, EN 61000-3-12 (draft) and IEEE 519-1992 are reviewed...... are stored in tables. The third level is found by analytical calculations and very precise results are obtained. The fourth level is the use of circuit-based simulators, which guarantees high precision even under non-ideal conditions. By use of the numerical circuit-based simulator SABER the phase...

  15. A mapping approach for distortion correction in sinusoidally scanned images

    Science.gov (United States)

    Khoury, J.; Woods, C. L.; Haji-saeed, Bahareh; Pyburn, Dana; Sengupta, Sandip K.; Kierstead, J.

    2006-04-01

    We have developed a mapping algorithm for correcting sinusoidally scanned images from their distortions. Our algorithm is based on an approximate relationship between linear and sinusoidal scanning. Straightforward implementation of this algorithm showed that the mapped image has either missing lines or redundant lines. The missing lines were filled by fusing the mapped image with its median filtered version. The implementation of this algorithm shows that it is possible to retrieve up to 96.43% of the original image, as measured by the recovered energy.

  16. Latency and distortion of electromagnetic trackers for augmented reality systems

    CERN Document Server

    Himberg, Henry

    2014-01-01

    Augmented reality (AR) systems are often used to superimpose virtual objects or information on a scene to improve situational awareness. Delays in the display system or inaccurate registration of objects destroy the sense of immersion a user experiences when using AR systems. AC electromagnetic trackers are ideal for these applications when combined with head orientation prediction to compensate for display system delays. Unfortunately, these trackers do not perform well in environments that contain conductive or ferrous materials due to magnetic field distortion without expensive calibration

  17. Beam-beam diagnostics from closed-orbit distortion

    Energy Technology Data Exchange (ETDEWEB)

    Furman, M.; Chin, Y.H.; Eden, J. [Lawrence Berkeley Lab., CA (United States); Kozanecki, W. [DAPNIA/SPP, CEN Saclay Gif-sur-Yvette, (FR)]|[Stanford Linear Accelerator Center, Menlo Park, CA (United States); Tennyson, J.; Ziemann, V. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1992-07-01

    We study the applicability of beam-beam deflection techniques as a tuning tool for asymmetric B factories, focusing on PEP-II as an example. Assuming that the closed orbits of the two beams are separated vertically at the interaction point by a local orbit bump that is nominally closed, we calculate the residual beam orbit distortions due to the beam-beam interaction. Difference orbit measurements, performed at points conveniently distant from the interaction point (IP), provide distinct signatures that can be used to maintain the beams in collision and perform detailed optical diagnostics at the IP. A proposal to test this method experimentally at the TRISTAN ring is briefly discussed.

  18. Children's memory distortions following social contact with a co-witness: disentangling social and cognitive mechanisms.

    Science.gov (United States)

    Bright-Paul, Alexandra; Jarrold, Christopher; Wright, Daniel B; Guillaume, Stephanie

    2012-01-01

    This study examined whether recalling an event with a co-witness influences children's recall. Individual 3-5-year-olds (n = 48) watched a film with a co-witness. Unbeknown to participants, the co-witness was watching an alternative version of the film. Afterwards both the co-witness and the participant answered questions about the film together (public recall), and the degree to which children conformed to the co-witness's alternative version of events was measured. Subsequently participants were questioned again individually (private recall). Children also completed false belief and inhibitory control tasks. By separating errors made in public and private, the results indicated that both social conformity (32% of errors) and memory distortion (68% of errors) played a role in co-witness influence. Inhibitory control predicted the likelihood of retracting errors in private, but only for children who failed (r = .66) rather than passed false belief tasks (r = -.10). The results suggest that children with a theory of mind conform in the company of the co-witness to avoid social embarrassment, while those a poor theory of mind conform on the basis of an inability to inhibit the co-witness's response. The findings contribute to our understanding of the motivations responsible for co-witness conformity across early childhood.

  19. Beyond consistency test of gravity with redshift-space distortions at quasilinear scales

    Science.gov (United States)

    Taruya, Atsushi; Koyama, Kazuya; Hiramatsu, Takashi; Oka, Akira

    2014-02-01

    Redshift-space distortions (RSDs) offer an attractive method to measure the growth of cosmic structure on large scales, and combining with the measurement of the cosmic expansion history, they can be used as cosmological tests of gravity. With the advent of future galaxy redshift surveys aiming at precisely measuring the RSD, an accurate modeling of RSD going beyond linear theory is a critical issue in order to detect or disprove small deviations from general relativity (GR). While several improved models of RSD have been recently proposed based on the perturbation theory (PT), the framework of these models heavily relies on GR. Here, we put forward a new PT prescription for RSD in general modified gravity models. As a specific application, we present theoretical predictions of the redshift-space power spectra in the f(R) gravity model, and compare them with N-body simulations. Using the PT template that takes into account the effects of both modifications of gravity and RSD properly, we successfully recover the fiducial model parameter in N-body simulations in an unbiased way. On the other hand, we found it difficult to detect the scale dependence of the growth rate in a model-independent way based on GR templates.

  20. The UV Plasmonic Behavior of Distorted Rhodium Nanocubes

    Directory of Open Access Journals (Sweden)

    Yael Gutiérrez

    2017-12-01

    Full Text Available For applications of surface-enhanced spectroscopy and photocatalysis, the ultraviolet (UV plasmonic behavior and charge distribution within rhodium nanocubes is explored by a detailed numerical analysis. The strongest plasmonic hot-spots and charge concentrations are located at the corners and edges of the nanocubes, exactly where they are the most spectroscopically and catalytically active. Because intense catalytic activity at corners and edges will reshape these nanoparticles, distortions of the cubical shape, including surface concavity, surface convexity, and rounded corners and edges, are also explored to quantify how significantly these distortions deteriorate their plasmonic and photocatalytic properties. The fact that the highest fields and highest carrier concentrations occur in the corners and edges of Rh nanocubes (NCs confirms their tremendous potential for plasmon-enhanced spectroscopy and catalysis. It is shown that this opportunity is fortuitously enhanced by the fact that even higher field and charge concentrations reside at the interface between the metal nanoparticle and a dielectric or semiconductor support, precisely where the most chemically active sites are located.

  1. Distortion outage minimization in Nakagami fading using limited feedback

    Directory of Open Access Journals (Sweden)

    Wang Chih-Hong

    2011-01-01

    Full Text Available Abstract We focus on a decentralized estimation problem via a clustered wireless sensor network measuring a random Gaussian source where the clusterheads amplify and forward their received signals (from the intra-cluster sensors over orthogonal independent stationary Nakagami fading channels to a remote fusion center that reconstructs an estimate of the original source. The objective of this paper is to design clusterhead transmit power allocation policies to minimize the distortion outage probability at the fusion center, subject to an expected sum transmit power constraint. In the case when full channel state information (CSI is available at the clusterhead transmitters, the optimization problem can be shown to be convex and is solved exactly. When only rate-limited channel feedback is available, we design a number of computationally efficient sub-optimal power allocation algorithms to solve the associated non-convex optimization problem. We also derive an approximation for the diversity order of the distortion outage probability in the limit when the average transmission power goes to infinity. Numerical results illustrate that the sub-optimal power allocation algorithms perform very well and can close the outage probability gap between the constant power allocation (no CSI and full CSI-based optimal power allocation with only 3-4 bits of channel feedback.

  2. An improved solution to geometric distortion using an orthogonal method

    Science.gov (United States)

    Peng, Huan-Wen; Peng, Qing-Yu; Wang, Na

    2017-02-01

    The geometric distortion of a CCD field of view has a direct influence on the positional measurements of CCD observations. In order to obtain high precision astrometric results, the geometric distortion should be derived and corrected precisely. As presented in our previous work, a convenient solution has been carried out and has also been applied to observations of Phoebe. In order to further improve the solution, an orthogonal method based on Zernike polynomials is used in this work. Four nights of CCD observations including Himalia, the sixth satellite of Jupiter, and open clusters (NGC 1664 or NGC 2324) on each night have been processed as an application. The observations were obtained from the 2.4 m telescope administered by Yunnan Observatories. The catalog UCAC4 was used to match reference stars in all of the CCD frames. The ephemeris of Himalia is retrieved from the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE). Our results show that the means of observed minus calculated (O-C) positional residuals are -0.034 and -0.026 arcsec in right ascension and declination, respectively. The corresponding standard deviations are {0.031}^{\\prime\\prime } and {0.028}^{\\prime\\prime }. The measurement dispersion is significantly improved compared to that by using our previous solution.

  3. Signal distortion from microelectrodes in clinical EEG acquisition systems

    Science.gov (United States)

    Stacey, William C.; Kellis, Spencer; Patel, Paras R.; Greger, Bradley; Butson, Christopher R.

    2012-10-01

    Many centers are now using high-density microelectrodes during traditional intracranial electroencephalography (iEEG) both for research and clinical purposes. These microelectrodes are FDA-approved and integrate into clinical EEG acquisition systems. However, the electrical characteristics of these electrodes are poorly described and clinical systems were not designed to use them; thus, it is possible that this shift into clinical practice could have unintended consequences. In this study, we characterized the impedance of over 100 commercial macro- and microelectrodes using electrochemical impedance spectroscopy (EIS) to determine how electrode properties could affect signal acquisition and interpretation. The EIS data were combined with the published specifications of several commercial EEG systems to design digital filters that mimic the behavior of the electrodes and amplifiers. These filters were used to analyze simulated brain signals that contain a mixture of characteristic features commonly observed in iEEG. Each output was then processed with several common quantitative EEG measurements. Our results show that traditional macroelectrodes had low impedances and produced negligible distortion of the original signal. Brain tissue and electrical wiring also had negligible filtering effects. However, microelectrode impedances were much higher and more variable than the macroelectrodes. When connected to clinical amplifiers, higher impedance electrodes produced considerable distortion of the signal at low frequencies (clinical systems. These results show that it is critical to account for variations in impedance when analyzing EEG from different-sized electrodes. Data from microelectrodes may yield misleading results unless recorded with high-impedance amplifiers.

  4. Scalable Fast Rate-Distortion Optimization for H.264/AVC

    Directory of Open Access Journals (Sweden)

    Yu Hongtao

    2006-01-01

    Full Text Available The latest H.264/AVC video coding standard aims at significantly improving compression performance compared to all existing video coding standards. In order to achieve this, variable block-size inter- and intra-coding, with block sizes as large as and as small as , is used to enable very precise depiction of motion and texture details. The Lagrangian rate-distortion optimization (RDO can be employed to select the best coding mode. However, exhaustively searching through all coding modes is computationally expensive. This paper proposes a scalable fast RDO algorithm to effectively choose the best coding mode without exhaustively searching through all the coding modes. The statistical properties of MBs are analyzed to determine the order of coding modes in the mode decision priority queue such that the most probable mode will be checked first, followed by the second most probable mode, and so forth. The process will be terminated as soon as the computed rate-distortion (RD cost is below a threshold which is content adaptive and is also dependent on the RD cost of the previous MBs. By adjusting the threshold we can choose a good tradeoff between timesaving and peak signal-to-noise (PSNR ratio. Experimental results show that the proposed fast RDO algorithm can drastically reduce the encoding time up to 50% with negligible loss of coding efficiency.

  5. Laboratory simulation of atmospheric turbulence induced optical wavefront distortion

    Science.gov (United States)

    Taylor, Travis Shane

    1999-11-01

    Many creative approaches have been taken in the past for simulating the effect that atmospheric turbulence has on optical beams. Most of the experimental architectures have been complicated and consisted of many optical elements as well as moving components. These techniques have shown a modicum of success; however, they are not completely controllable or predictable. A benchtop technique for experimentally producing one important effect that atmospheric turbulence has on optical beams (phase distortion) is presented here. The system is completely controllable and predictable while accurately representing the statistical nature of the problem. Previous experimentation in optical processing through turbulent media has demonstrated that optical wavefront distortions can be produced via spatial light modulating (SLM) devices, and most turbulence models and experimental results indicate that turbulence can be represented as a phase fluctuation. The amplitude distributions in the resulting far field are primarily due to propagation of the phase. Operating a liquid crystal television (LCTV) in the ``phase- mostly'' mode, a phase fluctuation type model for turbulence is utilized in the present investigation, and a real-time experiment for demonstrating the effects was constructed. For an optical system to simulate optical wavefront distortions due to atmospheric turbulence, the following are required: (1)An optical element that modulates the phasefront of an optical beam (2)A model and a technique for generating spatially correlated turbulence simulating distributions (3)Hardware and software for displaying and manipulating the information addressing the optical phase modulation device The LCTV is ideal for this application. When operated in the ``phase-mostly'' mode some LCTVs can modulate the phasefront of an optical beam by as much as 2π and an algorithm for generating spatially correlated phase screens can be constructed via mathematical modeling software such as

  6. A Feminist Critique of Rational-Choice Theories: Implications for Sociology.

    Science.gov (United States)

    England, Paula

    1989-01-01

    Provides a feminist critique of rational-choice theory and the interdisciplinary feminist theories of sociology. Applies the separative model of self to four assumptions of the neoclassical economics version of rational-choice theory. Uses research on marital power to illustrate how removing distorting assumptions can help illuminate sociological…

  7. Quantum electronics basic theory

    CERN Document Server

    Fain, V M; Sanders, J H

    1969-01-01

    Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai

  8. Evaluation of spatial-encoding-related geometric distortion in magnetic resonance imaging

    Science.gov (United States)

    Hong, Cheol Pyo; Lee, Dong Hoon; Lee, Man Woo; Woo, Youngkeun

    2012-12-01

    This study demonstrated the characteristics of spatial encoding-related geometric distortion in magnetic resonance imaging (MRI) by using a phantom with known physical dimensions to detect geometric distortion in MR scans. The amount of distortion was calculated as the difference between the physical coordinates of control points in the phantom and those of the corresponding points in the distorted MR image of the phantom. The phase and the frequency encoding directions were swapped to acquire a phantom image for movement of a patient table 120 mm to the right and left, allowing comprehensive distortion mapping over the isocentric plane and the entire field of view (FOV) along the spatial encoding. The geometric distortion of phase encoding directions over the entire FOV was small compared to the distortion of frequency encoding directions. The maximum absolute deviations were 28.00 mm and 20.00 mm along the frequency and the phase encoding directions over the entire FOV, respectively. The mean absolute deviations along the frequency and the phase encoding directions were 2.85 mm and 1.97 mm, respectively. Although geometric distortion along the phase encoding axis near the isocenter was small, the distortion increased slightly toward the peripheral regions. The distortion of the phase encoding direction in the peripheral region can be severely affected by the imaging gradient's nonlinearity.

  9. Dislocation Field Theory in 2D: Application to Graphene

    OpenAIRE

    Lazar, Markus

    2015-01-01

    A two-dimensional (2D) dislocation continuum theory is being introduced. The present theory adds elastic rotation, dislocation density, and background stress to the classical energy density of elasticity. This theory contains four material moduli. Two characteristic length scales are defined in terms of the four material moduli. Non-singular solutions of the stresses and elastic distortions of an edge dislocation are calculated. It has been pointed out that the elastic strain agrees well with...

  10. A method for the dynamic correction of B0-related distortions in single-echo EPI at 7T.

    Science.gov (United States)

    Dymerska, Barbara; Poser, Benedikt A; Barth, Markus; Trattnig, Siegfried; Robinson, Simon D

    2016-07-07

    We propose a method to calculate field maps from the phase of each EPI in an fMRI time series. These field maps can be used to correct the corresponding magnitude images for distortion caused by inhomogeneity in the static magnetic field. In contrast to conventional static distortion correction, in which one 'snapshot' field map is applied to all subsequent fMRI time points, our method also captures dynamic changes to B0 which arise due to motion and respiration. The approach is based on the assumption that the non-B0-related contribution to the phase measured by each radio-frequency coil, which is dominated by the coil sensitivity, is stable over time and can therefore be removed to yield a field map from EPI. Our solution addresses imaging with multi-channel coils at ultra-high field (7T), where phase offsets vary rapidly in space, phase processing is non-trivial and distortions are comparatively large. We propose using dual-echo gradient echo reference scan for the phase offset calculation, which yields estimates with high signal-to-noise ratio. An extrapolation method is proposed which yields reliable estimates for phase offsets even where motion is large and a tailored phase unwrapping procedure for EPI is suggested which gives robust results in regions with disconnected tissue or strong signal decay. Phase offsets are shown to be stable during long measurements (40min) and for large head motions. The dynamic distortion correction proposed here is found to work accurately in the presence of large motion (up to 8.1°), whereas a conventional method based on single field map fails to correct or even introduces distortions (up to 11.2mm). Finally, we show that dynamic unwarping increases the temporal stability of EPI in the presence of motion. Our approach can be applied to any EPI measurements without the need for sequence modification. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Optimal redshift weighting for redshift-space distortions

    Science.gov (United States)

    Ruggeri, Rossana; Percival, Will J.; Gil-Marín, Héctor; Zhu, Fangzhou; Zhao, Gong-Bo; Wang, Yuting

    2017-01-01

    The low-statistical errors on cosmological parameters promised by future galaxy surveys will only be realized with the development of new, fast, analysis methods that reduce potential systematic problems to low levels. We present an efficient method for measuring the evolution of the growth of structure using redshift-space distortions (RSDs), that removes the need to make measurements in redshift shells. We provide sets of galaxy-weights that cover a wide range in redshift, but are optimized to provide differential information about cosmological evolution. These are derived to optimally measure the coefficients of a parametrization of the redshift-dependent matter density, which provides a framework to measure deviations from the concordance ΛCDM cosmology, allowing for deviations in both geometric and/or growth. We test the robustness of the weights by comparing with alternative schemes and investigate the impact of galaxy bias. We extend the results to measure the combined anisotropic baryon acoustic oscillation and RSD signals.

  12. Improvements on Semi-Classical Distorted-Wave model

    Energy Technology Data Exchange (ETDEWEB)

    Sun Weili; Watanabe, Y.; Kuwata, R. [Kyushu Univ., Fukuoka (Japan); Kohno, M.; Ogata, K.; Kawai, M.

    1998-03-01

    A method of improving the Semi-Classical Distorted Wave (SCDW) model in terms of the Wigner transform of the one-body density matrix is presented. Finite size effect of atomic nuclei can be taken into account by using the single particle wave functions for harmonic oscillator or Wood-Saxon potential, instead of those based on the local Fermi-gas model which were incorporated into previous SCDW model. We carried out a preliminary SCDW calculation of 160 MeV (p,p`x) reaction on {sup 90}Zr with the Wigner transform of harmonic oscillator wave functions. It is shown that the present calculation of angular distributions increase remarkably at backward angles than the previous ones and the agreement with the experimental data is improved. (author)

  13. Alternative agricultural price distortions for CGE analysis, 2007 and 2011

    DEFF Research Database (Denmark)

    Jensen, Hans Grinsted; Anderson, Kym

    A recent World Bank research project has generated an annual time series of distortions to agricultural incentives over the past half century for 82 countries, the majority of which are low-and middle-income countries. In this memorandum, the current GTAP version 8 Data Base may be modified...... to incorporate this dataset, using an Altertax simulation. The files required for this Altertax simulation, including parameter files and shock files are generated by the DAItoGTAP.tab file which will accommodate any level of aggregation of the GTAP database. In this memorandum the data files required to modify...... the GTAP v8.1 database can be downloaded. Data required to modify the GTAP v9 database will be available at a later date when v9 is released....

  14. India’s Distorted Sex Ratio: Dire Consequences for Girls

    Science.gov (United States)

    Roberts, Lisa R.; Montgomery, Susanne B.

    2017-01-01

    Female gender discrimination related to cultural preference for males is a common global problem, especially in Asian countries. Numerous laws intended to prevent discrimination on the basis of gender have been passed in India, yet the distorted female-to-male sex ratio seems to show worsening tendencies. Using detailed, two-year longitudinal chart abstraction data about delivery records of a private mission hospital in rural India, we explored if hospital birth ratio data differed in comparison to regional data, and what demographic and contextual variables may have influenced these outcomes. Using quantitative chart abstraction and qualitative contextual data, study results showed the female-to-male ratio was lower than the reported state ratio at birth. In the context of India’s patriarchal structure, with its strong son preference, women are under tremendous pressure or coerced to access community-based, sex-selective identification and female fetus abortion. Nurses may be key to turning the tide. PMID:28286369

  15. India's Distorted Sex Ratio: Dire Consequences for Girls.

    Science.gov (United States)

    Roberts, Lisa R; Montgomery, Susanne B

    2016-01-01

    Female gender discrimination related to cultural preference for males is a common global problem, especially in Asian countries. Numerous laws intended to prevent discrimination on the basis of gender have been passed in India, yet the distorted female-to-male sex ratio seems to show worsening tendencies. Using detailed, two-year longitudinal chart abstraction data about delivery records of a private mission hospital in rural India, we explored if hospital birth ratio data differed in comparison to regional data, and what demographic and contextual variables may have influenced these outcomes. Using quantitative chart abstraction and qualitative contextual data, study results showed the female-to-male ratio was lower than the reported state ratio at birth. In the context of India's patriarchal structure, with its strong son preference, women are under tremendous pressure or coerced to access community-based, sex-selective identification and female fetus abortion. Nurses may be key to turning the tide.

  16. Rate-distortion optimised video transmission using pyramid vector quantisation.

    Science.gov (United States)

    Bokhari, Syed; Nix, Andrew R; Bull, David R

    2012-08-01

    Conventional video compression relies on interframe prediction (motion estimation), intra frame prediction and variable-length entropy encoding to achieve high compression ratios but, as a consequence, produces an encoded bitstream that is inherently sensitive to channel errors. In order to ensure reliable delivery over lossy channels, it is necessary to invoke various additional error detection and correction methods. In contrast, techniques such as Pyramid Vector Quantisation have the ability to prevent error propagation through the use of fixed length codewords. This paper introduces an efficient rate distortion optimisation algorithm for intra-mode PVQ which offers similar compression performance to intra H.264/AVC and Motion JPEG 2000 while offering inherent error resilience. The performance of our enhanced codec is evaluated for HD content in the context of a realistic (IEEE 802.11n) wireless environment. We show that PVQ provides high tolerance to corrupted data compared to the state of the art while obviating the need for complex encoding tools.

  17. Virtual Instrument for Modelling and Measuring the Distorting State

    Directory of Open Access Journals (Sweden)

    Katalin ÁGOSTON

    2012-12-01

    Full Text Available This paper presents a virtual instrument developed in LabView for modeling generating a distorting voltage by adding harmonics with different level and phase to the base signal. The other virtual instrument models the single-phase power system and calculates the power and energy proper to the harmonics. The virtual instrument can be enlarged very easy for three-phase power system. Developing proper conditional circuits for current and voltage acquisition the virtual instrument can be modify to measure real data. The designed virtual instrument calculates from the acquired data the active and reactive power, the power factor and the frequency and level of the harmonics in case of nonsinusoidal signals.

  18. Asymmetric Hardware Distortions in Receive Diversity Systems: Outage Performance Analysis

    KAUST Repository

    Javed, Sidrah

    2017-02-22

    This paper studies the impact of asymmetric hardware distortion (HWD) on the performance of receive diversity systems using linear and switched combining receivers. The asymmetric attribute of the proposed model motivates the employment of improper Gaussian signaling (IGS) scheme rather than the traditional proper Gaussian signaling (PGS) scheme. The achievable rate performance is analyzed for the ideal and non-ideal hardware scenarios using PGS and IGS transmission schemes for different combining receivers. In addition, the IGS statistical characteristics are optimized to maximize the achievable rate performance. Moreover, the outage probability performance of the receive diversity systems is analyzed yielding closed form expressions for both PGS and IGS based transmission schemes. HWD systems that employ IGS is proven to efficiently combat the self interference caused by the HWD. Furthermore, the obtained analytic expressions are validated through Monte-Carlo simulations. Eventually, non-ideal hardware transceivers degradation and IGS scheme acquired compensation are quantified through suitable numerical results.

  19. Topological edge states of distorted photonic Kagome lattices

    Science.gov (United States)

    Ni, Xiang; Alu, Andrea; Khanikaev, Alexander B.

    2017-08-01

    We demonstrate that the distorted Kagome lattice formed by two-dimensional(2d) array of dielectric rods embedded in air exhibits a new class of topological states characterized by a topological invariant number in Pauli vector space. The Kagome lattice can be considered as a 2d analogue of the Su-Schrieffer-Heeger (SSH) model, which displays a phase transition by detuning the relative amplitudes of the inter-cell and intra-cell hopping terms. The phase transition is accompanied by the opening of a complete band gap in the Brillouin zone, which may host topological edge states on either the truncated end of the lattice or at the domain walls between topological nontrivial and trivial domains. To further reveal the connection between the bulk invariance and edge states, polarizations of shrunken and expanded effects are calculated. Our first-principles simulations based on finite element method (FEM) are used to design the lattice and confirm the analytic prediction.

  20. Role of Cognitive Factors and Distortions in Adolescent Suicides

    Directory of Open Access Journals (Sweden)

    Bedriye Oncu

    2013-06-01

    Full Text Available Suicide is one of the leading causes of adolescent death and is an important clinical problem. According to World Health Organization, it is the third most common cause of death for 15-44 age group worldwide and is the second most common cause of death for 15-24 age group in Turkey. The presence of a psychiatric disorder and previous suicidal acts, social, cultural and family related factors are well known predictors of suicide. However, cognitive developmental level and schemes are as important as the other factors. For prevention and treatment, it is essential to understand cognitive factors that lead adolescents to suicide. Cognitive factors and distortions that might have a role in adolescent suicides are hopelessness, problem solving deficits, cognitive rigidity, dichotomous thinking, perfectionism, personalizing, and catastrophising and time perspective. In this article, adolescent suicide and related cognitive factors are briefly reviewed.

  1. Structural distortion in thiourea-mixed ADP crystals

    Energy Technology Data Exchange (ETDEWEB)

    Jayarama, A. [Department of Physics, Mangalore University, Mangalagangotri 574199 (India)]. E-mail: jrmarasalike@yahoo.co.in; Dharmaprakash, S.M. [Department of Physics, Mangalore University, Mangalagangotri 574199 (India)

    2006-11-15

    Single crystals of ammonium dihydrogen phosphate (ADP) mixed with different mole concentrations of thiourea were grown using slow evaporation solution technique at 30deg. C. In order to study the effect of mixing thiourea on the structural characteristics of ADP, X-ray diffraction studies were carried out on the crystals using Shimadzu X-ray diffractometer with Cu K{alpha} radiation. X-ray study revealed that the structures of the thiourea-mixed ADP are slightly distorted compared to the pure ADP crystal structure. Inclusion of thiourea enhances the growth of (1-bar 00) plane of the ADP crystal. Thiourea-mixed ADP crystals were found to have maximum inclusion, as the thiourea concentration was 10mol%.

  2. Susceptibility to cognitive distortions: the role of eating pathology.

    Science.gov (United States)

    Coelho, Jennifer S; Ouellet-Courtois, Catherine; Purdon, Christine; Steiger, Howard

    2015-01-01

    Thought-Shape Fusion (TSF) and Thought-Action Fusion (TAF) are cognitive distortions that are associated with eating and obsessional pathology respectively. Both involve the underlying belief that mere thoughts and mental images can lead to negative outcomes. TSF involves the belief that food-related thoughts lead to weight gain, body dissatisfaction, and perceptions of moral wrong-doing. TAF is more general, and involves the belief that merely thinking about a negative event (e.g., a loved one getting into a car accident) can make this event more likely to happen, and leads to perceptions of moral wrong-doing. However, the shared susceptibility across related cognitive distortions-TAF and TSF-has not yet been studied. The effects of TSF and TAF inductions in women with an eating disorder (n = 21) and a group of healthy control women with no history of an eating disorder (n = 23) were measured. A repeated-measures design was employed, with all participants exposed to a TSF, TAF and neutral induction during three separate experimental sessions. Participants' cognitive and behavioral responses were assessed. Individuals with eating disorders were more susceptible to TSF and TAF than were control participants, demonstrating more neutralization behavior after TSF and TAF inductions (i.e., actions to try to reduce the negative effects of the induction), and reporting higher levels of trait TAF and TSF than did controls. Individuals with eating disorders are particularly susceptible to both TAF and TSF. Clinical implications of these findings will be discussed.

  3. SYNCHRONIZATION SIGNAL DISTORTION IN SUBCARRIER WAVE QUANTUM KEY DISTRIBUTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Varvara D. Dubrovskaya

    2017-07-01

    Full Text Available Subject of Research. The paper deals with temperature effects dependence of the synchronization signal parameters in an optical fiber cable for a subcarrier wave quantum communication system. Two main causes of signal distortion are considered: the change in the refractive index as a function of the average daily temperature and the dispersion effects in the optical fiber, over which the signal is transmitted in the system. Method. To account for these effects, a temperature model has been created. The signal delay is calculated as a result of external influences in the system working with a standard fiber-optic cable. Real operational conditions are taken into account, including cable laying conditions, average daily temperature and wind speed. Main Results. The simulations were carried out on the standard single-mode fiber ITU-T G.652D. It was experimentally obtained that the maximum calculated phase mismatch of the synchronization signal for a system operating at a 100 km fiber length corresponds to a 1.7 ps signal time delay. The maximum operating intervals of the system without the use of phase adjustment are calculated. The obtained results are used to improve the parameters of the subcarrier wave quantum communication system. It is determined that the change in the refractive index in the fiber causes significant distortion of the signal. It is shown that stable operation is possible with adjustment every 158 ms. The additional phase delay resulting from the dispersion effects should be adjusted every 2.3 hours. Practical Relevance. The obtained results enable to optimize the parameters of the subcarrier wave quantum key distribution system to increase the overall key generation rate.

  4. Abortion and distortion of justice in the law.

    Science.gov (United States)

    Dickens, B M

    1989-01-01

    Examples are cited of how the current policy in the U.S. favoring the pro-life philosophy is distorting government and court judgements. Appointment of Supreme Court justices and executive officials higher than assistant cabinet secretaries is subject to political ideology. Pro-life activists oppose wrongful birth tort actions, with the result that handicapped children are denied damages. In contrast they support legal action on behalf of stillborn fetuses. Similarly since "Webster" the pro-life movement disallows wrongful birth suits, so financial expenses cannot be recovered to help pay for a handicapped child. This may paradoxically force couples into abortion if they cannot risk supporting a severely handicapped child. Again, the trend is the same for wrongful life claims where handicapped children as a result of professional negligence seek compensation to provide for their care. Stillborn fetuses in this case can recover damages, resulting in windfall gains to their estate. The possibility of finding on behalf of a stillborn fetus may prompt doctors to induce abortion rather than have to pay damages. Another distortion of the notion of the transcending blessing of life valued more in the abstract than an individual's suffering or insentience is the judgement that comatose persons must continue to receive forced life-support against their family's claim of right to decline care. There have been a few cases where pregnant women have been charged as criminals, forcibly hospitalized and operated on to legally protect the fetus. This trend may cause pregnant women to avoid prenatal care rather than be forced to live a state-prescribed life style. Other examples of misdirected compassion of the pro-life movement are loss of practicing obstetricians, of RU 486 and other contraceptive methods, of fetal tissue research, and potential loss of in vitro fertilization to couples who wish to have 1 or 2 babies only.

  5. An Iterative Distortion Compensation Algorithm for Camera Calibration Based on Phase Target.

    Science.gov (United States)

    Xu, Yongjia; Gao, Feng; Ren, Hongyu; Zhang, Zonghua; Jiang, Xiangqian

    2017-05-23

    Camera distortion is a critical factor affecting the accuracy of camera calibration. A conventional calibration approach cannot satisfy the requirement of a measurement system demanding high calibration accuracy due to the inaccurate distortion compensation. This paper presents a novel camera calibration method with an iterative distortion compensation algorithm. The initial parameters of the camera are calibrated by full-field camera pixels and the corresponding points on a phase target. An iterative algorithm is proposed to compensate for the distortion. A 2D fitting and interpolation method is also developed to enhance the accuracy of the phase target. Compared to the conventional calibration method, the proposed method does not rely on a distortion mathematical model, and is stable and effective in terms of complex distortion conditions. Both the simulation work and experimental results show that the proposed calibration method is more than 100% more accurate than the conventional calibration method.

  6. A study of the effect of group delay distortion on an SMSK satellite communications channel

    Science.gov (United States)

    Kerczewski, Robert J.

    1987-01-01

    The effects of group delay distortion on an SMSK satellite communications channel have been investigated. Software and hardware simulations have been used to determine the effects of channel group delay variations with frequency on the bit error rate for a 220 Mbps SMSK channel. These simulations indicate that group delay distortions can significantly degrade the bit error rate performance. The severity of the degradation is dependent on the amount, type, and spectral location of the group delay distortion.

  7. Cognitive distortions and gambling near-misses in Internet Gaming Disorder: A preliminary study

    OpenAIRE

    Wu, Yin; Sescousse, Guillaume; Yu, Hongbo; Clark, Luke; Li, Hong

    2018-01-01

    Increased cognitive distortions (i.e. biased processing of chance, probability and skill) are a key psychopathological process in disordered gambling. The present study investigated state and trait aspects of cognitive distortions in 22 individuals with Internet Gaming Disorder (IGD) and 22 healthy controls. Participants completed the Gambling Related Cognitions Scale as a trait measure of cognitive distortions, and played a slot machine task delivering wins, near-misses and full-misses. Rati...

  8. Prediction of numerical distortion after welding with various welding sequences and clampings

    Directory of Open Access Journals (Sweden)

    S. Kastelic

    2010-10-01

    Full Text Available Welding simulation of a test cover for hydropower plant was made due to very large dimensions of the cover. The main aim was to predict distortion after welding in order to avoid machining the cover. Welding process was simulated with the Sysweld program to keep distortion in desired limits. Various welding sequences and clamping conditions were calculated to reduce the distortion. Calculation of microstructure constituents in virtual complex geometry of joints was also analyzed.

  9. DISTORTION OF 16MnCr5 STEEL PARTS DURING LOW-PRESSURE CARBURIZING

    Directory of Open Access Journals (Sweden)

    Konrad Dybowski

    2017-03-01

    This article presents a study of the distortion rate of workpieces carburized at low pressure then quenched in nitrogen at 1.4MPa. By comparing the distortion which takes place during the carburizing stage only and the carburizing combined with post-carburizing heat treatment it will be possible to assess the distortion rate and its causes at the different stages of the heat treatment process.

  10. A high-order model of rotating stall in axial compressors with inlet distortion

    Directory of Open Access Journals (Sweden)

    Peng LIN

    2017-06-01

    Full Text Available In this paper, a high-order distortion model is proposed for analyzing the rotating stall inception process induced by inlet distortion in axial compressors. A distortion-generating screen in the compressor inlet is considered. By assuming a quadratic function for the local flow total pressure-drop, the existing Mansoux model is extended to include the effects of static inlet distortion, and a new high-order distortion model is derived. To illustrate the effectiveness of the distortion model, numerical simulations are performed on an eighteenth-order model. It is demonstrated that long length-scale disturbances emerge out of the distorted background flow, and further induce the onset of rotating stall in advance. In addition, the circumferential non-uniform distribution and time evolution of the axial flow are also shown to be consistent with the existing features. It is thus shown that the high-order distortion model is capable of describing the transient behavior of stall inception and will contribute further to stall detection under inlet distortion.

  11. Acceptable distortion and magnification of images on reflective surfaces in an augmented reality system

    Science.gov (United States)

    Yamamoto, Shoji; Hosokawa, Natsumi; Yokoya, Mayu; Tsumura, Norimichi

    2016-12-01

    In this paper, we investigated the consistency of visual perception for the change of reflection images in an augmented reality setting. Reflection images with distortion and magnification were generated by changing the capture position of the environment map. Observers evaluated the distortion and magnification in reflection images where the reflected objects were arranged symmetrically or asymmetrically. Our results confirmed that the observers' visual perception was more sensitive to changes in distortion than in magnification in the reflection images. Moreover, the asymmetrical arrangement of reflected objects effectively expands the acceptable range of distortion compared with the symmetrical arrangement.

  12. The Effects of Visual Feedback Distortion with Unilateral Leg Loading on Gait Symmetry.

    Science.gov (United States)

    Tobar, Carlos; Martinez, Eva; Rhouni, Nada; Kim, Seung-Jae

    2018-02-01

    Our prior work provides evidence that visual feedback distortion drives an implicit adaptation; a gradual distortion of visual representation of step length modulated subjects' step lengths away from symmetry. To further explore the effect of the visual feedback distortion on unconscious change in step symmetry, we investigated whether such adaptation would occur even in the presence of altered limb mechanics by adding mass to one side of the leg. 26 subjects performed three 8-min trials (weight only, weight plus visual feedback, and weight plus visual feedback distortion) of treadmill walking. During the weight only trial, the subjects wore a 5 lb mass around the right ankle. The modification of limb inertia caused asymmetric gait. The visual feedback showing right and left step length information as bar graphs was displayed on a computer screen. To add visual feedback distortion, we increased the length of one side of the visual bars by 10% above the actual step length, and the visual distortion was implemented for the side that took longer in response to the added mass. We found that even when adjustments were made to unilateral loading, the subjects spontaneously changed their step symmetry in response to the visual distortion, which resulted in a more symmetric gait. This change may be characterized by sensory prediction errors, and our results suggest that visual feedback distortion has a significant impact on gait symmetry regardless of other conditions affecting limb mechanics. A rehabilitation program employing visual feedback distortion may provide an effective way to restore gait symmetry.

  13. The role of visual similarity and memory in body model distortions.

    Science.gov (United States)

    Saulton, Aurelie; Longo, Matthew R; Wong, Hong Yu; Bülthoff, Heinrich H; de la Rosa, Stephan

    2016-02-01

    Several studies have shown that the perception of one's own hand size is distorted in proprioceptive localization tasks. It has been suggested that those distortions mirror somatosensory anisotropies. Recent research suggests that non-corporeal items also show some spatial distortions. In order to investigate the psychological processes underlying the localization task, we investigated the influences of visual similarity and memory on distortions observed on corporeal and non-corporeal items. In experiment 1, participants indicated the location of landmarks on: their own hand, a rubber hand (rated as most similar to the real hand), and a rake (rated as least similar to the real hand). Results show no significant differences between rake and rubber hand distortions but both items were significantly less distorted than the hand. Experiments 2 and 3 explored the role of memory in spatial distance judgments of the hand, the rake and the rubber hand. Spatial representations of items measured in experiments 2 and 3 were also distorted but showed the tendency to be smaller than in localization tasks. While memory and visual similarity seem to contribute to explain qualitative similarities in distortions between the hand and non-corporeal items, those factors cannot explain the larger magnitude observed in hand distortions. Copyright © 2015. Published by Elsevier B.V.

  14. Finite element study of growth stress formation in wood and related distortion of sawn timber

    DEFF Research Database (Denmark)

    Ormarsson, Sigurdur; Dahlblom, O.; Johansson, M.

    2009-01-01

    Lack of straightness in timber is the most frequent complaint regarding solid (and laminated) timber products worldwide. Nowadays, customers demand higher quality in the shape stability of wood products than they did earlier. The final distortion of timber boards is caused mostly by moisture......-related stresses in wood (drying distortions) and growth-related stresses (distortions appearing when logs are split up to timber boards by sawing). To get more knowledge on how these distortions can be reduced in wooden products, there is a need for improved understanding of this material behaviour through good...

  15. String Theory

    OpenAIRE

    Marino Beiras, Marcos

    2011-01-01

    We give an overview of the relations between matrix models and string theory, focusing on topological string theory and the Dijkgraaf--Vafa correspondence. We discuss applications of this correspondence and its generalizations to supersymmetric gauge theory, enumerative geometry and mirror symmetry. We also present a brief overview of matrix quantum mechanical models in superstring theory.

  16. Game Theory

    DEFF Research Database (Denmark)

    Game Theory is a collection of short interviews based on 5 questions presented to some of the most influential and prominent scholars in game theory. We hear their views on game theory, its aim, scope, use, the future direction of game theory and how their work fits in these respects....

  17. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

    The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

  18. Higher-order neural network software for distortion invariant object recognition

    Science.gov (United States)

    Reid, Max B.; Spirkovska, Lilly

    1991-01-01

    The state-of-the-art in pattern recognition for such applications as automatic target recognition and industrial robotic vision relies on digital image processing. We present a higher-order neural network model and software which performs the complete feature extraction-pattern classification paradigm required for automatic pattern recognition. Using a third-order neural network, we demonstrate complete, 100 percent accurate invariance to distortions of scale, position, and in-plate rotation. In a higher-order neural network, feature extraction is built into the network, and does not have to be learned. Only the relatively simple classification step must be learned. This is key to achieving very rapid training. The training set is much smaller than with standard neural network software because the higher-order network only has to be shown one view of each object to be learned, not every possible view. The software and graphical user interface run on any Sun workstation. Results of the use of the neural software in autonomous robotic vision systems are presented. Such a system could have extensive application in robotic manufacturing.

  19. P2-5: Retrospective Perceptual Distortion of Position Representation Does Not Lead to Delayed Localization

    Directory of Open Access Journals (Sweden)

    Ricky K C Au

    2012-10-01

    Full Text Available Previous studies have reported retrospective influences of visual events occurring after a target event. In the attentional attraction effect, a task-irrelevant position cue presented after a target stimulus has been found to distort the perceived position of the target. The present study explored the temporal relationship between the stimulus presentation and speed of response in this effect, by measuring the reaction time in conditions with (or without the cue presented before, at the same time, or after the target presentation. If the processing speed for the stimuli were equal, the time separation between the presentation of target and cue should lead to a delay in response time when compared with the condition where both stimuli are simultaneously presented. The results indicated no significant difference in reaction time for such comparison. As an interpretation of the results, the processing of the rapid dynamic attentional shift induced by the cue might be faster than that for the target localization, and completed before the establishment of conscious percept without affecting the overall response time.

  20. Distorted temporal consciousness and preserved knowing consciousness in confabulation: a case study.

    Science.gov (United States)

    La Corte, Valentina; George, Nathalie; Pradat-Diehl, Pascale; Barba, Gianfranco Dalla

    2011-01-01

    In this study we describe a patient, TA, who developed a chronic amnesic-confabulatory syndrome, following rupture of a right internal carotid siphon aneurysm. Our aim was to elucidate as fully as possible the nature of TA's impairment and to test the hypothesis of confabulation as reflecting a dysfunction of Temporal Consciousness, i.e., to become aware of something as part of a personal past, present or future. TA's confabulations were present in answers to questions tapping Temporal Consciousness, i.e., autobiographical episodic memory, orientation in time and place, and foresight of personal future. In contrast, confabulations were not observed in answers to questions tapping Knowing Consciousness, i.e., to become aware of something as a meaning or as an element of impersonal knowledge. In fact, he had normal access to semantic knowledge, including foresight of impersonal future. TA's brain MRI showed lesions involving the right hippocampus, parahippocampal gyrus, fornix, mammillary bodies, and thalamus. Moreover TA showed sub-cortical lesions involving the caudate and putamen nuclei bilaterally, a lesion site not commonly described in amnesic-confabulatory syndrome. We suggest that this pattern of results is better accounted for within the framework of the Memory, Consciousness and Temporality Theory and reflects a specific distortion of Temporal Consciousness.

  1. Improving the Stability of Organic Semiconductors: Distortion Energy versus Aromaticity in Substituted Bistetracene

    KAUST Repository

    Thomas, Simil

    2016-11-15

    Polycyclic aromatic hydrocarbons (PAHs) have been widely explored as molecular semiconductors in organic electronic devices such as field-effect transistors or solar cells. However, their tendency to undergo photooxidation is a primary limitation to their practical applications. Bistetracene derivatives have recently been demonstrated to possess much larger photo oxidation stability than the widely investigated pentacene and rubrene, while maintaining high charge-carrier mobilities. Here, using several levels of density functional theory, we identify the origin of the increased stability of bistetracene with respect to molecular oxygen by systematically investigating the [4 + 2] cycloaddition (Diels Alder) photooxidation reaction mechanism. Importantly, our computational results indicate that endoperoxide formation in bis(2-(trimethylsilyl)ethynyl) bistetracene (BT) occurs not on the ring with least aromaticity, but rather on the ring with smallest distortion energy. This feature was subsequently confirmed by experimental NMR analyses. The oxidation activation barriers of bistetracene, pentacene, and rubrene are found to be 17.7, 13.6, and 14.4 kcal/mol, respectively, in agreement with the observed order of stability of these molecules with respect to oxidation reactions in solution. In the cases of BT and pentacene, the rates of electron transfer to create charged species (PAH(+) and O-2) are at least two orders of magnitude lower than that of the charge recombination process (back to PAH and O-2); for rubrene, both of these processes are calculated to be of the same order of magnitude, in agreement with experimental electron paramagnetic resonance spectroscopy observations.

  2. The giant piezoelectric effect: electric field induced monoclinic phase or piezoelectric distortion of the rhombohedral parent?

    CERN Document Server

    Kisi, E H; Forrester, J S; Howard, C J

    2003-01-01

    Lead zinc niobate-lead titanate (PZN-PT) single crystals show very large piezoelectric strains for electric fields applied along the unit cell edges e.g. [001] sub R. It has been widely reported that this effect is caused by an electric field induced phase transition from rhombohedral (R3m) to monoclinic (Cm or Pm) symmetry in an essentially continuous manner. Group theoretical analysis using the computer program ISOTROPY indicates phase transitions between R3m and Cm (or Pm) must be discontinuous under Landau theory. An analysis of the symmetry of a strained unit cell in R3m and a simple expansion of the piezoelectric strain equation indicate that the piezoelectric distortion due to an electric field along a cell edge in rhombohedral perovskite-based ferroelectrics is intrinsically monoclinic (Cm), even for infinitesimal electric fields. PZN-PT crystals have up to nine times the elastic compliance of other piezoelectric perovskites and it might be expected that the piezoelectric strains are also very large. ...

  3. Similarity-based distortion of visual short-term memory is due to perceptual averaging.

    Science.gov (United States)

    Dubé, Chad; Zhou, Feng; Kahana, Michael J; Sekuler, Robert

    2014-03-01

    A task-irrelevant stimulus can distort recall from visual short-term memory (VSTM). Specifically, reproduction of a task-relevant memory item is biased in the direction of the irrelevant memory item (Huang & Sekuler, 2010a). The present study addresses the hypothesis that such effects reflect the influence of neural averaging under conditions of uncertainty about the contents of VSTM (Alvarez, 2011; Ball & Sekuler, 1980). We manipulated subjects' attention to relevant and irrelevant study items whose similarity relationships were held constant, while varying how similar the study items were to a subsequent recognition probe. On each trial, subjects were shown one or two Gabor patches, followed by the probe; their task was to indicate whether the probe matched one of the study items. A brief cue told subjects which Gabor, first or second, would serve as that trial's target item. Critically, this cue appeared either before, between, or after the study items. A distributional analysis of the resulting mnemometric functions showed an inflation in probability density in the region spanning the spatial frequency of the average of the two memory items. This effect, due to an elevation in false alarms to probes matching the perceptual average, was diminished when cues were presented before both study items. These results suggest that (a) perceptual averages are computed obligatorily and (b) perceptual averages are relied upon to a greater extent when item representations are weakened. Implications of these results for theories of VSTM are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Oxygen vacancy related distortions in rutile Ti O2 nanoparticles: A combined experimental and theoretical study

    Science.gov (United States)

    Vásquez, G. C.; Karazhanov, S. Zh.; Maestre, D.; Cremades, A.; Piqueras, J.; Foss, S. E.

    2016-12-01

    The effects of doubly ionized oxygen vacancies (VO 2 +) on the electronic structure and charge distribution in rutile Ti O2 are studied by combining first-principles calculations based on density functional theory and experimental results from x-ray photoelectron and x-ray absorption measurements carried out in synchrotron facilities on rutile Ti O2 nanoparticles. The generalized gradient approximation of the Perdew-Burke-Ernzerhof functional has demonstrated its suitability for the analysis of the VO 2 + defects in rutile Ti O2 . It has been found that the presence of empty electronic states at the conduction band shifted ˜1 eV from t2 g and eg states can be associated with local distortions induced by VO 2 + defects, in good agreement with Gauss-Lorentzian band deconvolution of experimental O K -edge spectra. The asymmetry of t2 g and eg bands at the O-K edge has been associated with VO 2 +, which can enrich the understanding of studies where the presence of these defects plays a key role, as in the case of doped Ti O2 .

  5. Biomechanical simulation of needle insertion into cornea based on distortion energy failure criterion.

    Science.gov (United States)

    Su, Peng; Yang, Yang; Zhang, Leiyu; Huang, Long

    2016-01-01

    This paper is mainly about biomechanical behavior of needle insertion into cornea, and proposes a failure criterion to simulate the insertion process which has attracted considerable attention due to its importance for the minimally invasive treatment. In the process of needle insertion into cornea, tiny and complex insertion force is generated due to contact between needle and soft tissue. Based on the distortion energy theory, there is proposed a failure criterion of corneal material that can solve contact problem between rigid body and biological tissue in insertion simulation, where Cauchy stress of corneal material is the key to numerical calculation. A finite element model of in vivo cornea is built, and the cornea constrained by sclera is simplified to two layers containing epithelium and stroma. Considering the hyper-viscoelastic property of corneal material, insertion simulation is carried out. By insertion experiment, the insertion force increases with insertion depth accompanying obvious fluctuations. Different insertion forces are generated at different speeds. The punctured locations are obvious in the force-displacement curves. The results of insertion simulation are generally consistent with experimental data. Maps of von Mises stress reflect the tissue injury of the cornea during insertion process, and punctured status corresponds to the point in the curves. The ability of this study to reproduce the behavior of needle insertion into cornea opens a promising perspective for the control of robotic surgery operation as well as the real-time simulation of corneal suture surgery.

  6. Quantifying the Effect of 3T Magnetic Resonance Imaging Residual System Distortions and Patient-Induced Susceptibility Distortions on Radiation Therapy Treatment Planning for Prostate Cancer.

    Science.gov (United States)

    Adjeiwaah, Mary; Bylund, Mikael; Lundman, Josef A; Karlsson, Camilla Thellenberg; Jonsson, Joakim H; Nyholm, Tufve

    2017-10-20

    To investigate the effect of magnetic resonance system- and patient-induced susceptibility distortions from a 3T scanner on dose distributions for prostate cancers. Combined displacement fields from the residual system and patient-induced susceptibility distortions were used to distort 17 prostate patient CT images. VMAT dose plans were initially optimized on distorted CT images and the plan parameters transferred to the original patient CT images to calculate a new dose distribution. Maximum residual mean distortions of 3.19 mm at a radial distance of 25 cm and maximum mean patient-induced susceptibility shifts of 5.8 mm were found using the lowest bandwidth of 122 Hz per pixel. There was a dose difference of resonance scanners are larger than residual system distortions after using vendor-supplied 3-dimensional correction for the delineated regions studied. However, errors in dose due to disturbed patient outline and shifts caused by patient-induced susceptibility effects are below 0.5%. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Effects of olivocochlear feedback on distortion product otoacoustic emissions in guinea pig.

    Science.gov (United States)

    Kujawa, S G; Liberman, M C

    2001-09-01

    Activation of ipsilaterally responsive olivocochlear (OC) neurons by sound produces rapid, post-onset alterations in the 2f1-f2 distortion product otoacoustic emission (DPOAE). The present study investigates the frequency and level dependence of this ipsilateral OC effect in the anesthetized guinea pig, compares its magnitude and sign to OC effects elicited by contralateral sound ("contralateral" OC effect), and characterizes the influence of such activity on steady-state DPOAE amplitude. DPOAEs were measured with fine time resolution in response to primary stimuli varied systematically in frequency and level. DPOAEs showed rapid and remarkably stereotyped post-onset amplitude alterations. These ipsilateral OC effects were greater for high (8-12 kHz) than for low (2-4 kHz) f2 primary frequencies and for higher primary levels (70-80 dB SPL). For any f2/f1 pair, the sign as well as the magnitude of the ipsilateral effects varied with. primary level ratio. For example, with L1 fixed at 75 and L2 varied in 1-dB steps from 60 to 75 dB SPL, DPOAE amplitude underwent a stereotyped progression from post-onset increases at the lowest levels of the f2 primary to post-onset decreases at the highest levels. At intermediate levels, near the region of sign change (L2 = 5-10 dB below L1), post-onset effects were often particularly large (as great as 20 dB). These large ipsilateral OC effects were always associated with "dips" in the DPOAE amplitude vs. level functions, and both disappeared after OC section. Although smaller in magnitude, contralateral OC effects were identical to ipsilateral effects in frequency and level dependence and in form.

  8. Bed form dynamics in distorted lightweight scale models

    Science.gov (United States)

    Aberle, Jochen; Henning, Martin; Ettmer, Bernd

    2016-04-01

    The adequate prediction of flow and sediment transport over bed forms presents a major obstacle for the solution of sedimentation problems in alluvial channels because bed forms affect hydraulic resistance, sediment transport, and channel morphodynamics. Moreover, bed forms can affect hydraulic habitat for biota, may introduce severe restrictions to navigation, and present a major problem for engineering structures such as water intakes and groynes. The main body of knowledge on the geometry and dynamics of bed forms such as dunes originates from laboratory and field investigations focusing on bed forms in sand bed rivers. Such investigations enable insight into the physics of the transport processes, but do not allow for the long term simulation of morphodynamic development as required to assess, for example, the effects of climate change on river morphology. On the other hand, this can be achieved through studies with distorted lightweight scale models allowing for the modification of the time scale. However, our understanding of how well bed form geometry and dynamics, and hence sediment transport mechanics, are reproduced in such models is limited. Within this contribution we explore this issue using data from investigations carried out at the Federal Waterways and Research Institute in Karlsruhe, Germany in a distorted lightweight scale model of the river Oder. The model had a vertical scale of 1:40 and a horizontal scale of 1:100, the bed material consisted of polystyrene particles, and the resulting dune geometry and dynamics were measured with a high spatial and temporal resolution using photogrammetric methods. Parameters describing both the directly measured and up-scaled dune geometry were determined using the random field approach. These parameters (e.g., standard deviation, skewness, kurtosis) will be compared to prototype observations as well as to results from the literature. Similarly, parameters describing the lightweight bed form dynamics, which

  9. White-Light Phase-Conjugate Mirrors as Distortion Correctors

    Science.gov (United States)

    Frazier, Donald; Smith, W. Scott; Abdeldayem, Hossin; Banerjee, Partha

    2010-01-01

    White-light phase-conjugate mirrors would be incorporated into some optical systems, according to a proposal, as means of correcting for wavefront distortions caused by imperfections in large optical components. The proposal was given impetus by a recent demonstration that white, incoherent light can be made to undergo phase conjugation, whereas previously, only coherent light was known to undergo phase conjugation. This proposal, which is potentially applicable to almost any optical system, was motivated by a need to correct optical aberrations of the primary mirror of the Hubble Space telescope. It is difficult to fabricate large optical components like the Hubble primary mirror and to ensure the high precision typically required of such components. In most cases, despite best efforts, the components as fabricated have small imperfections that introduce optical aberrations that adversely affect imaging quality. Correcting for such aberrations is difficult and costly. The proposed use of white-light phase conjugate mirrors offers a relatively simple and inexpensive solution of the aberration-correction problem. Indeed, it should be possible to simplify the entire approach to making large optical components because there would be no need to fabricate those components with extremely high precision in the first place: A white-light phase-conjugate mirror could correct for all the distortions and aberrations in an optical system. The use of white-light phase-conjugate mirrors would be essential for ensuring high performance in optical systems containing lightweight membrane mirrors, which are highly deformable. As used here, "phase-conjugate mirror" signifies, more specifically, an optical component in which incident light undergoes time-reversal phase conjugation. In practice, a phase-conjugate mirror would typically be implemented by use of a suitably positioned and oriented photorefractive crystal. In the case of a telescope comprising a primary and secondary

  10. Improved Control Strategies for a DFIG-Based Wind-Power Generation System with SGSC under Unbalanced and Distorted Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Yao, Jun; Yu, Mengting; Hu, Weihao

    2016-01-01

    with SGSC is established by taking both the negative-sequence and harmonic components of the grid voltages into consideration with multiple synchronous rotating reference frames. Under network unbalance and harmonic distortion situations, stator voltage can be kept symmetrical and sinusoidal by the control...... of SGSC, which indicates that the rotor-side converter (RSC) can be still controlled with the traditional vector control strategy without modifications. Meanwhile, for the parallel grid-side converter (PGSC), three sets of selectable control targets are identified and their corresponding current...... with a dual-frequency resonant (PI-DFR) controller in the positive synchronous reference frame for PGSC and SGSC are designed to achieve the rapid and precise regulation of the corresponding components simultaneously. Simulation studies on a DFIG system with SGSC under network unbalance and harmonic distorted...

  11. The dominant folding route minimizes backbone distortion in SH3.

    Directory of Open Access Journals (Sweden)

    Heiko Lammert

    Full Text Available Energetic frustration in protein folding is minimized by evolution to create a smooth and robust energy landscape. As a result the geometry of the native structure provides key constraints that shape protein folding mechanisms. Chain connectivity in particular has been identified as an essential component for realistic behavior of protein folding models. We study the quantitative balance of energetic and geometrical influences on the folding of SH3 in a structure-based model with minimal energetic frustration. A decomposition of the two-dimensional free energy landscape for the folding reaction into relevant energy and entropy contributions reveals that the entropy of the chain is not responsible for the folding mechanism. Instead the preferred folding route through the transition state arises from a cooperative energetic effect. Off-pathway structures are penalized by excess distortion in local backbone configurations and contact pair distances. This energy cost is a new ingredient in the malleable balance of interactions that controls the choice of routes during protein folding.

  12. Differences in cognitive distortions between problem and social gamblers.

    Science.gov (United States)

    Joukhador, Jackie; Maccallum, Fiona; Blaszczynski, Alex

    2003-06-01

    The cognitive model of gambling argues that irrational beliefs and erroneous perceptions including illusions of control, superstitious beliefs, expectancies of winning, attributional biases, selective memory, and entrapment play a pivotal role in the development and maintenance of impaired control over patterns of gambling behaviours. Assessment strategies using self-report, behavioural inferences, and verbalizations produced by 'thinking aloud' techniques, and the effectiveness of treatment interventions designed to correct cognitive distortions have provided substantive empirical evidence supporting this model. However, research has yet to measure such differences between the quality, intensity, or conviction of specific dysfunctional beliefs held by problem in contrast to social gamblers. At the theoretical level, the absence of such demonstrable differences would undermine the validity of the cognitive explanatory model. Based on a review of the available literature, a preliminary measure to assess differences in irrational gambling beliefs was constructed and administered to a convenience sample of 56 problem gamblers and 52 social gamblers. In support of the cognitive model, analysis indicated that, compared to social gamblers, problem gamblers endorsed more irrational beliefs across all domains except for the variable of 'denial'. Implications for research issues relevant to the identification of irrational beliefs that may be subjected to challenge within a cognitive therapy paradigm are mentioned.

  13. Distorted Character Recognition Via An Associative Neural Network

    Science.gov (United States)

    Messner, Richard A.; Szu, Harold H.

    1987-03-01

    The purpose of this paper is two-fold. First, it is intended to provide some preliminary results of a character recognition scheme which has foundations in on-going neural network architecture modeling, and secondly, to apply some of the neural network results in a real application area where thirty years of effort has had little effect on providing the machine an ability to recognize distorted objects within the same object class. It is the author's belief that the time is ripe to start applying in ernest the results of over twenty years of effort in neural modeling to some of the more difficult problems which seem so hard to solve by conventional means. The character recognition scheme proposed utilizes a preprocessing stage which performs a 2-dimensional Walsh transform of an input cartesian image field, then sequency filters this spectrum into three feature bands. Various features are then extracted and organized into three sets of feature vectors. These vector patterns that are stored and recalled associatively. Two possible associative neural memory models are proposed for further investigation. The first being an outer-product linear matrix associative memory with a threshold function controlling the strength of the output pattern (similar to Kohonen's crosscorrelation approach [1]). The second approach is based upon a modified version of Grossberg's neural architecture [2] which provides better self-organizing properties due to its adaptive nature. Preliminary results of the sequency filtering and feature extraction preprocessing stage and discussion about the use of the proposed neural architectures is included.

  14. Selective distortion of body image by asynchronous visuotactile stimulation.

    Science.gov (United States)

    Perez-Marcos, Daniel; Martini, Matteo; Fuentes, Christina T; Bellido Rivas, Anna I; Haggard, Patrick; Sanchez-Vives, Maria V

    2017-12-18

    In the rubber hand illusion (RHI), a rubber hand is felt as being part of one's body. This illusion is evoked by providing synchronous visuotactile stimulation to the fake and real hands. Asynchronous visuotactile stimulation is known not to produce such an illusion of ownership, being commonly used as the control condition. Here we explored the impact of synchronous and asynchronous visuotactile stimulation on the body image. We combined the induction of the RHI with a quantitative test for the internal representation of body metrics (i.e., the positions of key fiducial points on the body relative to each other). We found a significant recalibration of the upper/lower arm lengths following asynchronous visuotactile stimulation. In particular, we observed a selective elongation of the lower arm, a distortion typical of deafferentation. Conversely, synchronous visuotactile stimulation did not alter the estimation of the arm segments' length. Our findings are consistent with a dynamic internal representation of body image that is continuously updated based on incoming multisensory information. Furthermore, the use of asynchronous multisensory stimulation as a neutral condition should be reconsidered since it introduces changes in the body image. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Distortion, Messianism, and Apocalyptic Time in The Satanic Verses

    Directory of Open Access Journals (Sweden)

    Clara Eisinger

    2013-05-01

    Full Text Available Salman Rushdie’s novel The Satanic Verses presents its readers with a striking perspective on apocalypse. Taking place in the context of a modernist, migrant worldview, this apocalypse works to unsettle its participating characters by teaching them how to create a world in which they might someday belong. Though often defined as destructive, the apocalypse as I define it involves a reaching for or gesture towards the impossible, which the Verses achieves through massive temporal distortion. Linear time finds itself subverted; characters’ narratives speed up or slow down, forcing them to question their various adventures in 1980s London. Rushdie’s protagonist Saladin Chamcha re-grasps and reinvents his world; his other protagonist, Gibreel Farishta, does not. For one man, apocalypse becomes a means of empowerment; for another, it develops into a black hole. Unlike real black holes, however, Rushdie’s apocalypse does not kill all who venture into it, but instead stretches its hardiest entrants both emotionally and intellectually before dropping them into a new universe. Apocalypse and the post-apocalyptic are not therefore to be feared but to be reached for: worthy achievements for those individuals who can survive the risk, the compression, and the disorientation to emerge in a ‘post’ that is not a wasteland but a realm of ceaseless energetic creation—a realm which allows migrants to construct for themselves better lives in the 21st century world.

  16. Pixel hybrid photon detector magnetic distortions characterization and compensation

    CERN Document Server

    Aglieri-Rinella, G; D'Ambrosio, Carmelo; Forty, Roger W; Gys, Thierry; Patel, Mitesh; Piedigrossi, Didier; Van Lysebetten, Ann

    2004-01-01

    The LHCb experiment requires positive kaon identification in the momentum range 2-100 GeV/c. This is provided by two ring imaging Cherenkov detectors. The stringent requirements on the photon detectors are fully satisfied by the novel pixel hybrid photon detector, HPD. The HPD is a vacuum tube with a quartz window, S20 photo-cathode, cross-focusing electron optics and a silicon anode encapsulated within the tube. The anode is a 32*256 pixels hybrid detector, with a silicon sensor bump-bonded onto a readout chip containing 8192 channels with analogue front-end and digital read-out circuitry. An external magnetic field influences the trajectory of the photoelectrons and could thereby degrade the inherent excellent space resolution of the HPD. The HPDs must be operational in the fringe magnetic field of the LHCb magnet. This paper reports on an extensive experimental characterization of the distortion effects. The characterization has allowed the development of parameterisations and of a compensation algorithm. ...

  17. Metal dependence of the nonplanar distortion of octaalkyltetraphenylporphyrins

    Energy Technology Data Exchange (ETDEWEB)

    Sparks, L.D.; Shelnutt, J.A. (Sandia National Laboratories, Albuquerque, NM (United States) Univ. of New Mexico, Albuquerque (United States)); Medforth, C.J.; Senge, M.O.; Smith, K.M. (Univ. of California, Davis (United States)); Park, M.S.; Ondrias, M.R. (Univ. of New Mexico, Albuquerque (United States)); Chamberlain, J.R. (Sandia National Laboratories, Albuquerque, NM (United States))

    1993-01-27

    The biological activity of porphyrins and related tetrapyrroles in proteins may be modulated by nonplanar conformational distortions; consequently, two aspects of nonplanarity have been investigated in the highly nonplanar octaalkyltetraphenylporphyrins (OATPPs). In the first part, the effect of the central metal ion (M = Ni(II), Co(II), Cu(II), Zn(II), Co(III), Fe(III)) on the conformation of the OATPP macrocycle has been determined. Crystallographic studies reveal that the sterically encumbered, nonplanar porphyrin 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrin (OETPP) remains sufficiently flexible to show a small decrease in nonplanarity for large metal ions. This decrease in nonplanarity for the OETPP metal complexes is predicted by using a molecular mechanics force field derived from structural and vibrational data for planar metalloporphyrins. A detailed analysis of the crystal structures of the Co(II) and Cu(II) complexes of OETPP reveals that the metal-dependent changes in bond lengths and bond angles are qualitatively similar to the changes observed for the OEP complexes. As the metal size increases, both OEPs and OETPPs exhibit expansion of the meso bridges (increases in the C[sub [alpha

  18. Issues in Dutch palliative care: readjusting a distorted image.

    Science.gov (United States)

    Gordijn, B; Visser, A

    2000-08-01

    This issue presents a review of several issues in Dutch palliative care, paying attention to readjusting a distorted image due to the euthanasia practice in the Netherlands. A few articles stress the evolution of palliative care (especially in the UK and the Netherlands), developed palliative care services in the Netherlands, and new developments in the Netherlands concerning the prevention of euthanasia through palliative care. Also the needs concerning palliative care for children as well as for chronic psycho-geriatrics patients are presented. Further attention is paid to the organisation of palliative care, focusing at evaluative research on palliative support teams, caring for caregivers (experiences and evaluation of interventions for palliative care teams), and effects of transmural care on coordination and continuity of care. Finally, some articles focus on ethical considerations in the treatment of pain in hospice movement, ethical evaluation of clinical trials in palliative care, and the role of informed consent in palliative radiotherapy, stressing the participation of patients and proxies in treatment decisions. Conclusions are presented on the consequences for educational and counselling aspects of palliative care.

  19. An inventory of bispectrum estimators for redshift space distortions

    Science.gov (United States)

    Regan, Donough

    2017-12-01

    In order to best improve constraints on cosmological parameters and on models of modified gravity using current and future galaxy surveys it is necessary maximally exploit the available data. As redshift-space distortions mean statistical translation invariance is broken for galaxy observations, this will require measurement of the monopole, quadrupole and hexadecapole of not just the galaxy power spectrum, but also the galaxy bispectrum. A recent (2015) paper by Scoccimarro demonstrated how the standard bispectrum estimator may be expressed in terms of Fast Fourier Transforms (FFTs) to afford an extremely efficient algorithm, allowing the bispectrum multipoles on all scales and triangle shapes to be measured in comparable time to those of the power spectrum. In this paper we present a suite of alternative proxies to measure the three-point correlation multipoles. In particular, we describe a modal (or plane wave) decomposition to capture the information in each multipole in a series of basis coefficients, and also describe three compressed estimators formed using the skew-spectrum, the line correlation function and the integrated bispectrum, respectively. As well as each of the estimators offering a different measurement channel, and thereby a robustness check, it is expected that some (especially the modal estimator) will offer a vast data compression, and so a much reduced covariance matrix. This compression may be vital to reduce the computational load involved in extracting the available three-point information.

  20. Workload induced spatio-temporal distortions and safety of flight

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.L.; Weisgerber, S.A. (Los Alamos National Lab., NM (USA); Naval Weapons Center, China Lake, CA (USA))

    1989-01-01

    A theoretical analysis of the relationship between cognitive complexity and the perception of time and distance is presented and experimentally verified. Complex tasks produce high rates of mental representation which affect the subjective sense of duration and, through the subjective time scale, the percept of distance derived from dynamic visual cues (i.e., visual cues requiring rate integration). The analysis of the interrelationship of subjective time and subjective distance yields the prediction that, as a function of cognitive complexity, distance estimates derived from dynamic visual cues will be longer than the actual distance whereas estimates based on perceived temporal duration will be shorter than the actual distance. This prediction was confirmed in an experiment in which subjects (both pilots and non-pilots) estimated distances using either temporal cues or dynamic visual cues. The distance estimation task was also combined with secondary loading tasks in order to vary the overall task complexity. The results indicated that distance estimates based on temporal cues were underestimated while estimates based on visual cues were overestimated. This spatio-temporal distortion effect increased with increases in overall task complexity. 30 refs., 6 figs., 1 tab.

  1. Computer vision distortion correction of scanning probe microscopy images.

    Science.gov (United States)

    Gaponenko, Iaroslav; Tückmantel, Philippe; Ziegler, Benedikt; Rapin, Guillaume; Chhikara, Manisha; Paruch, Patrycja

    2017-04-06

    Since its inception, scanning probe microscopy (SPM) has established itself as the tool of choice for probing surfaces and functionalities at the nanoscale. Although recent developments in the instrumentation have greatly improved the metrological aspects of SPM, it is still plagued by the drifts and nonlinearities of the piezoelectric actuators underlying the precise nanoscale motion. In this work, we present an innovative computer-vision-based distortion correction algorithm for offline processing of functional SPM measurements, allowing two images to be directly overlaid with minimal error - thus correlating position with time evolution and local functionality. To demonstrate its versatility, the algorithm is applied to two very different systems. First, we show the tracking of polarisation switching in an epitaxial Pb(Zr0.2Ti0.8)O3 thin film during high-speed continuous scanning under applied tip bias. Thanks to the precise time-location-polarisation correlation we can extract the regions of domain nucleation and track the motion of domain walls until the merging of the latter in avalanche-like events. Secondly, the morphology of surface folds and wrinkles in graphene deposited on a PET substrate is probed as a function of applied strain, allowing the relaxation of individual wrinkles to be tracked.

  2. Weaving and bonding method to prevent warp and fill distortion

    Science.gov (United States)

    Farley, Gary L. (Inventor)

    1997-01-01

    A method to prevent fiber distortion in textile materials employed in a modified weaving process. In a first embodiment, a tacifier in powder form is applied to the yarn and melted while on the fabric. Cool air is then supplied after the tacifier has melted to expedite the solidification of the tacifier. In a second embodiment, a solution form of a tacifier is used by dissolving the tacifier into a solvent that has a high evaporation rate. The solution is then sprayed onto the fabric or fill yarn as each fill yarn is inserted into a shed of the fabric. A third embodiment applies the tacifier in a liquid form that has not been dissolved in a solvent. That is, the tacifier is melted and is sprayed as a liquid onto the fabric or fill yarn as it is being extracted from a fill yarn spool prior to the fill yarn being inserted into the shed of the fabric. A fourth embodiment employs adhesive yarns contained as an integral part of the warp or fill yarn. Additional tacifier material is not required because a matrix is used as the tacifier. The matrix is then locally melted using heating elements on clamping bars or take-up rollers, is cooled, if necessary, and solidified.

  3. Rate-distortion optimization for compressive video sampling

    Science.gov (United States)

    Liu, Ying; Vijayanagar, Krishna R.; Kim, Joohee

    2014-05-01

    The recently introduced compressed sensing (CS) framework enables low complexity video acquisition via sub- Nyquist rate sampling. In practice, the resulting CS samples are quantized and indexed by finitely many bits (bit-depth) for transmission. In applications where the bit-budget for video transmission is constrained, rate- distortion optimization (RDO) is essential for quality video reconstruction. In this work, we develop a double-level RDO scheme for compressive video sampling, where frame-level RDO is performed by adaptively allocating the fixed bit-budget per frame to each video block based on block-sparsity, and block-level RDO is performed by modelling the block reconstruction peak-signal-to-noise ratio (PSNR) as a quadratic function of quantization bit-depth. The optimal bit-depth and the number of CS samples are then obtained by setting the first derivative of the function to zero. In the experimental studies the model parameters are initialized with a small set of training data, which are then updated with local information in the model testing stage. Simulation results presented herein show that the proposed double-level RDO significantly enhances the reconstruction quality for a bit-budget constrained CS video transmission system.

  4. Transient and distortion product evoked otoacoustic emissions in premature infants

    Directory of Open Access Journals (Sweden)

    Oliveira, Carlos Augusto Costa Pires de

    2009-09-01

    Full Text Available Introduction: The correlation between the transient (TEOE and distortion product (DPOAE evoked otoacoustic emissions may be useful for the neonatal auditory screening, mainly in premature infants, who have risk indicators for hearing deficiency. There is need for deepening the knowledge regarding this population cochlea features. Objective: To compare the TEOE and DPOAE in premature infants. To analyze the reproducibility in the TEOE, the amplitude and the sign/noise ratio in the TEOE and DPOAE. Method: TEOE and DPOAE were carried out in 50 premature infants. The tests were correlated as for the criterion "pass/failure" and compared according to amplitude and sign/noise ratio parameters. Results: The TEOE were present in 71% of the sample. The frequency of 3kHz presented a better performance in the average reproducibility, amplitude and sign/noise ratio. The DPOAE were present in 97% of the sample. The frequency of 2kHz had a major average amplitude, the values of the sign/noise ratio increased proportionally in the high frequencies. There was a strong correlation between TEOE and DPOAE in the "pass/failure" criterion (p=0.006. Conclusion: The correlation between the TEOE and DPOAE results was significant. But one method compliments the other and both may be used in the TAN.

  5. Local Cooling during Welding : Prediction and Control of Residual Stresses and Buckling Distortion

    NARCIS (Netherlands)

    Van der Aa, E.M.

    2007-01-01

    One of the major problems during welding of thin plate structures is the occurrence of buckling distortion. This type of distortion is caused by the formation of compressive welding stresses; when these stresses exceed a certain critical stress level, the structure will buckle. Most methods for

  6. Control of welding distortion during gas metal arc welding of AH36 plates by stress engineering

    NARCIS (Netherlands)

    Pazooki, A.M.A.; Hermans, M.J.M.; Richardson, I.M.

    2017-01-01

    Welding residual stress and distortion are strongly linked together. One of the ways to control or reduce the welding distortions is the manipulation of the generated stresses during welding, and final residual stresses exist in the workpiece (stress engineering). In this paper, the control of gas

  7. Numerical and semi-analytical modelling of the process induced distortions in pultrusion

    DEFF Research Database (Denmark)

    Baran, Ismet; Carlone, P.; Hattel, Jesper Henri

    2013-01-01

    , the transient distortions are inferred adopting a semi-analytical procedure, i.e. post processing numerical results by means of analytical methods. The predictions of the process induced distortion development using the aforementioned methods are found to be qualitatively close to each other...

  8. Cognitive distortions as a component and treatment focus of pathological gambling: a review.

    Science.gov (United States)

    Fortune, Erica E; Goodie, Adam S

    2012-06-01

    The literature on the role of cognitive distortions in the understanding and treatment of pathological gambling (PG) is reviewed, with sections focusing on (a) conceptual underpinnings of cognitive distortions, (b) cognitive distortions related to PG, (c) PG therapies that target cognitive distortions, (d) methodological factors and outcome variations, and (e) conclusions and prescriptive recommendations. The conceptual background for distortions related to PG lies in the program of heuristics and biases (Kahneman & Tversky, 1974) as well as other errors identified in basic psychology. The literature has focused on distortions arising from the representativeness heuristic (gambler's fallacy, overconfidence, and trends in number picking), the availability heuristic (illusory correlation, other individuals' wins, and inherent memory bias), and other sources (the illusion of control and double switching). Some therapies have incorporated cognitive restructuring within broader cognitive-behavioral therapies, with success. Other therapies have focused more narrowly on correcting distorted beliefs, more often with limited success. It is concluded that the literature establishes the role of cognitive distortions in PG and suggests therapies with particularly good promise, but is in need of further enrichment.

  9. Sexual Coping, General Coping and Cognitive Distortions in Incarcerated Rapists and Child Molesters

    Science.gov (United States)

    Feelgood, Steven; Cortoni, Franca; Thompson, Anthony

    2005-01-01

    Sexual coping, general coping and cognitive distortions were investigated in 25 rapists, 36 child molesters and 25 violent offenders. Rapists did not report more support for rape-supportive distortions than the violent offender comparison group. Child molesters scored higher than the other groups on the measure of molestation-supportive…

  10. Increasing Honest Responding on Cognitive Distortions in Child Molesters: The Bogus Pipeline Procedure

    Science.gov (United States)

    Gannon, Theresa A.

    2006-01-01

    Professionals conclude that child molesters (CMs) hold offense-supportive beliefs (or cognitive distortions) from CMs' questionnaire responses. Because questionnaires are easily faked, we asked 32 CMs to complete a cognitive distortion scale under standard conditions (Time 1). A week later (Time 2), the same CMs completed the scale again. This…

  11. Cognitive Distortions and Blame Attribution in Sex Offenders against Adults and Children.

    Science.gov (United States)

    Blumenthal, Stephen; Gudjonsson, Gisli; Burns, Jan

    1999-01-01

    This study compared sex offenders against children and adults on measures of cognitive distortions relating to sex with children and rape and a measure of blame attribution. Child sexual offenders endorsed more cognitive distortions relating to sex with children and reported more guilt-feeling attributions. (Author/DB)

  12. Gambling Motives: Do They Explain Cognitive Distortions in Male Poker Gamblers?

    Science.gov (United States)

    Mathieu, Sasha; Barrault, Servane; Brunault, Paul; Varescon, Isabelle

    2017-06-17

    Gambling behavior is partly the result of varied motivations leading individuals to participate in gambling activities. Specific motivational profiles are found in gamblers, and gambling motives are closely linked to the development of cognitive distortions. This cross-sectional study aimed to predict cognitive distortions from gambling motives in poker players. The population was recruited in online gambling forums. Participants reported gambling at least once a week. Data included sociodemographic characteristics, the South Oaks Gambling Screen, the Gambling Motives Questionnaire-Financial and the Gambling-Related Cognition Scale. This study was conducted on 259 male poker gamblers (aged 18-69 years, 14.3% probable pathological gamblers). Univariate analyses showed that cognitive distortions were independently predicted by overall gambling motives (34.8%) and problem gambling (22.4%) (p cognitive distortions (p cognitive distortions are a good discriminating factor of gambling problems, showing a close inter-relationship between gambling motives, cognitive distortions and the severity of gambling. These data are consistent with the following theoretical process model: gambling motives lead individuals to practice and repeat the gambling experience, which may lead them to develop cognitive distortions, which in turn favor problem gambling. This study opens up new research perspectives to understand better the mechanisms underlying gambling practice and has clinical implications in terms of prevention and treatment. For example, a coupled motivational and cognitive intervention focused on gambling motives/cognitive distortions could be beneficial for individuals with gambling problems.

  13. General cognitive distortions and body satisfaction : Findings from the Netherlands and Curaçao

    NARCIS (Netherlands)

    Dijkstra, Pieternel; Barelds, Dick; Van Brummen-Girigori, Odette

    2017-01-01

    The present study examined ten cognitive distortions, as assessed by the Cognitive Distortions Scale (CDS), and their relations to body satisfaction among young women living in The Netherlands (n = 152) and Curaçao (a former colony of the Netherlands; n = 160). Findings showed that, in general,

  14. Do Cognitive Distortions Mediate the Test Anxiety-Examination Performance Relationship?

    Science.gov (United States)

    Putwain, David William; Connors, Liz; Symes, Wendy

    2010-01-01

    The aim of this study was to follow up exploratory research suggesting that the inverse relationship between test anxiety and examination performance was mediated by cognitive distortions such as catastrophising. Self-report data for measures of test anxiety and cognitive distortions were collected from students in their final year of compulsory…

  15. Distorted Pattern Recognition and Analysis with the Help of IEf Graph Representation

    Directory of Open Access Journals (Sweden)

    Adam Sedziwy

    2002-01-01

    Full Text Available An algorithm for distorted pattern recognition is presented. lt's generalization of M Flasinski results (Pattern Recognition, 27, 1-16, 1992. A new formalism allows to make both qualitative and quantitive distortion analysis. It also enlarges parser flexibility by extending the set of patterns which may be recognized.

  16. Perceptual quality prediction on authentically distorted images using a bag of features approach

    Science.gov (United States)

    Ghadiyaram, Deepti; Bovik, Alan C.

    2017-01-01

    Current top-performing blind perceptual image quality prediction models are generally trained on legacy databases of human quality opinion scores on synthetically distorted images. Therefore, they learn image features that effectively predict human visual quality judgments of inauthentic and usually isolated (single) distortions. However, real-world images usually contain complex composite mixtures of multiple distortions. We study the perceptually relevant natural scene statistics of such authentically distorted images in different color spaces and transform domains. We propose a “bag of feature maps” approach that avoids assumptions about the type of distortion(s) contained in an image and instead focuses on capturing consistencies—or departures therefrom—of the statistics of real-world images. Using a large database of authentically distorted images, human opinions of them, and bags of features computed on them, we train a regressor to conduct image quality prediction. We demonstrate the competence of the features toward improving automatic perceptual quality prediction by testing a learned algorithm using them on a benchmark legacy database as well as on a newly introduced distortion-realistic resource called the LIVE In the Wild Image Quality Challenge Database. We extensively evaluate the perceptual quality prediction model and algorithm and show that it is able to achieve good-quality prediction power that is better than other leading models. PMID:28129417

  17. Reactive Power Sharing and Voltage Harmonic Distortion Compensation of Droop Controlled Single Phase Islanded Microgrids

    DEFF Research Database (Denmark)

    Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril

    2014-01-01

    and reduction of the voltage harmonic distortion at the point of common coupling (PCC). Experimental results were then presented to show the suitability of the proposed algorithms in achieving reactive power sharing and in improving the voltage harmonic distortion at the PCC....

  18. Geometric Distortion in Image and Video Watermarking. Robustness and Perceptual Quality Impact

    NARCIS (Netherlands)

    Setyawan, I.

    2004-01-01

    The main focus of this thesis is the problem of geometric distortion in image and video watermarking. In this thesis we discuss the two aspects of the geometric distortion problem, namely the watermark desynchronization aspect and the perceptual quality assessment aspect. Furthermore, this thesis

  19. Trapped Fermionic clouds distorted from the trap shape due to many-body effects

    NARCIS (Netherlands)

    Haque, M.; Stoof, H.T.C.

    2007-01-01

    We present a general approach for describing trapped Fermi gases, when the cloud shape is distorted with respect to the trap shape. Our approach provides a consistent way to explore physics beyond the local density approximation, if this is necessary due to the distortion. We illustrate this by

  20. Distortion correction in fetal EPI using non-rigid registration with a Laplacian constraint.

    Science.gov (United States)

    Kuklisova Murgasova, Maria; Lockwood-Estrin, Georgia; Nunes, Rita G; Malik, Shaihan; Rutherford, Mary; Rueckert, Daniel; Hajnal, Joseph

    2017-02-09

    Geometric distortion induced by the main B0 field disrupts the consistency of fetal EPI data, on which diffusion and functional MRI is based. In this paper we present a novel data-driven method for simultaneous motion and distortion correction of fetal EPI. A motion-corrected and reconstructed T2 weighted ssFSE volume is used as a model of undistorted fetal brain anatomy. Our algorithm interleaves two registration steps: estimation of fetal motion parameters by aligning EPI slices to the model; and deformable registration of EPI slices to slices simulated from the undistorted model to estimate the distortion field. The deformable registration is regularized by a physically inspired Laplacian constraint, to model distortion induced by a source free background B0 field. Our experiments show that distortion correction significantly improves consistency of reconstructed EPI volumes with ssFSE volumes. Additionally, the estimated distortion fields are consistent with fields calculated from acquired field maps, and the Laplacian constraint is essential for estimation of plausible distortion fields. The EPI volumes reconstructed from different scans of the same subject were more consistent when the proposed method was used in comparison to EPI volumes reconstructed from data distortion corrected using a separately acquired B0 field map.

  1. A New High-Speed Low Distortion Switched-Current Cell

    DEFF Research Database (Denmark)

    Shah, Peter Jivan; Toumazou, Christofer

    1996-01-01

    A new switched-current cell is presented which simultaneously offers high speed, low distortion, low gain error, and a virtual ground input. In a simulation example 0.01% distortion was achieved at 50MHz sampling rate which makes the cell very well suited for high accuracy high speed filtering...

  2. Analytical Expressions for Harmonic Distortion at Low Frequencies due to Device Mismatch in CMOS Current Mirrors

    DEFF Research Database (Denmark)

    Bruun, Erik

    1999-01-01

    One of the origins of harmonic distortion in current mirrors is the inevitable mismatch between the mirror transistors. In this brief we examine both single current mirrors and complementary class AB current mirrors and develop analytical expressions for the mismatch induced harmonic distortion...

  3. Transmission ratio distortion in Arabidopsis lyrata: effects of population divergence and the S-locus

    DEFF Research Database (Denmark)

    Leppälä, J; Bechsgaard, J S; Schierup, M H

    2007-01-01

    We investigated transmission ratio distortion within an Icelandic population of Arabidopsis lyrata using 16 molecular markers unlinked to the S-locus. Transmission ratio distortion was found more often than expected by chance at the gametic level, but not at the genotypic or zygotic level. The ga...

  4. Effects of the sources of reionization on 21-cm redshift-space distortions

    NARCIS (Netherlands)

    Majumdar, Suman; Jensen, Hannes; Mellema, Garrelt; Chapman, Emma; Abdalla, Filipe B.; Lee, Kai-Yan; Iliev, Ilian T.; Dixon, Keri L.; Datta, Kanan K.; Ciardi, Benedetta; Fernandez, Elizabeth R.; Jelić, Vibor; Koopmans, Léon V. E.; Zaroubi, Saleem

    2016-01-01

    The observed 21 cm signal from the epoch of reionization will be distorted along the line of sight by the peculiar velocities of matter particles. These redshift-space distortions will affect the contrast in the signal and will also make it anisotropic. This anisotropy contains information about the

  5. Correcting the distortion of images taken with the ultraviolet imaging telescope

    Science.gov (United States)

    Greason, M. R.; Offenberg, Joel D.; Cornett, Robert H.; Hill, R. S.; Stecher, Theodore P.

    1994-11-01

    The Ultraviolet Imaging Telescope (UIT) cameras include two-stage magnetically focused image intensifiers that introduce small but significant geometrical distortions into the data. These distortions, which create positional offsets as large as 25 arcsec at the field edges, are corrected by the procedure described here to 2-3 arcsec, approximately the resolution of the images. The distortion is measured by comparing and correcting UIT images to digitized Guidestar survey plates of the same fields. Two-dimensional third-order polynomials are used to model the distortion. The models assume that the distortion is an instrumental effect, independent of mission elapsed time and target, and that the effect of distortion is an instrumental effect, independent of mission elapsed time and target, and that the effect of distortion in the center of each field is minimal. The models are used to improve computed astrometric plate solutions and to remove the geometric distortion while transforming the image to a standard north-up, ease-left orientation.

  6. Adolescent Body Image Distortion: A Consideration of Immigrant Generational Status, Immigrant Concentration, Sex and Body Dissatisfaction.

    Science.gov (United States)

    Kimber, Melissa; Georgiades, Katholiki; Couturier, Jennifer; Jack, Susan M; Wahoush, Olive

    2015-11-01

    Immigrant adolescents represent a significant and growing proportion of the population in the United States. Yet, little is known about their experiences of body image distortion. This is particularly concerning given that body image distortion has been identified as a significant and modifiable risk factor for a number of mental illnesses, including depression and eating disorders. This study uses multi-level modeling to examine the associations between immigrant generational status, neighborhood immigrant concentration, sex, body dissatisfaction and risk for body image distortion. Data come from the National Longitudinal Study of Adolescent Health and includes 10,962 11-19 year olds (49.6 % female). First generation immigrant females were significantly more likely than 3rd generation-or-later adolescents to experience underweight body image distortion. There was no association between neighborhood immigrant concentration and risk for body image distortion. Body dissatisfaction was associated with greater risk for underweight and overweight body image distortion, with the magnitude of underweight distortion risk significantly greater among 1st generation immigrants. Interventions that encourage the development of a healthy body image have the potential to reduce the onset and duration of body image distortion among immigrant and non-immigrant adolescents.

  7. Effects of lens distortion calibration patterns on the accuracy of monocular 3D measurements

    CSIR Research Space (South Africa)

    De Villiers, J

    2011-11-01

    Full Text Available A variety of lens distortion modelling techniques exist. Since they make use of different calibration metrics it is difficult to select one over the others. This work aims to compare lens distortion modelling techniques and calibration patterns in a...

  8. Relating 2f1 −f2 distortion product otoacoustic emission and equivalent rectangular bandwidth

    DEFF Research Database (Denmark)

    Christensen, Anders Tornvig; Ordoñez, Rodrigo; Hammershøi, Dorte

    2015-01-01

    To explore the extent of distortion product otoacoustic emission (DPOAE) toward low frequencies we measured in 21 normal-hearing human subjects its dependence on the ratio between evoking stimulus frequencies, f1 and f2, at 2f1-f2 distortion frequencies 88, 176 and 264 Hz. The "optimal" ratio evo...

  9. Cognitive representations (Metaphorical Conceptualizations) of past, future, joy, sadness and happiness in depressive and non-depressive subjects: cognitive distortions in depression at the level of notion.

    Science.gov (United States)

    Bartczak, Marlena; Bokus, Barbara

    2015-04-01

    The aim of this study was to see if and how the intensity of depression correlates with the cognitive representation of notions, and if any influence is reversed during remission. The cognitive representation indices used were the valence and number of metaphors produced for a notion. Three adult groups took part: persons with depression ([Formula: see text]), persons in remission ([Formula: see text]), and a control group ([Formula: see text]). Five notions were considered: PAST, FUTURE, JOY, SADNESS, and HAPPINESS. The Questionnaire of the Metaphorical Conceptualization of a Notion was used. The results showed that (a) depressive subjects did not have problems with metaphorical processing, (b) depressive subjects demonstrated strong interpretational negativism, (c) subjects during remission did not present distorted conceptual processing. The results are discussed in the context of theories of automatic metaphor processing, and conceptions of cognitive depressive distortions, in tasks requiring effort and substantial involvement of cognitive resources.

  10. Using Developmental Theory: When Not to Play Telephone Games

    Directory of Open Access Journals (Sweden)

    Sara Nora Ross

    2008-06-01

    Full Text Available As a powerful way to help understand the behaviors of people and social groupings of all kinds, developmental stage theory attracts attention and use outside of purely academic environments. These uses take the form of written materials and many kinds of interventions. The level of accuracy of developmental theory information generated and used outside of academe demonstrates wide variety. This variety is reflected in materials and interventions. The information used in materials and interventions becomes increasingly distorted as it becomes further removed from original theoretical sources. This has major implications for the ethics and expertise issues that are inherent in applied developmental theory. A classification scheme of information-use behaviors, many of which contribute to distortion processes, is used to code actual cases of creating and disseminating distorted developmental theory information, invoking the metaphor of telephone games. Case evidence indicates that casual, illustrative figures in a 2006 book by Wilber were used by others for various serious and theoretical purposes, and resulted in major distortions of developmental theory. Wilber’s figures represent problematic issues and errors, including distortion of theory, if they are used—as they indeed were—for any purpose more serious than his original purpose. Stemming from those issues and errors, a highly distorted picture of cognitive development and a pseudo-version of Commons and Richards’ Model of Hierarchical Complexity theory emerged, telephone game-like, in the cases discussed. Errors were widely propagated on the internet. Because outside of academe, specialized expertise in developmental theory is difficult to acquire, the sub-field of applied developmental theory requires not only accurate information but also strong communication ethics to govern behaviors of information providers. Such providers need to protect themselves at the same time they protect

  11. How Do Cognitive Distortions and Substance Related Problems Affect the Relationship Between Child Maltreatment and Adolescent Suicidal Ideation?

    Science.gov (United States)

    Miller, Adam B; Esposito-Smythers, Chrstianne

    2013-10-01

    The present study, informed by the cognitive-behavioral theory of suicide, is among the first studies to examine cognitive distortions and substance related problems as potential mediators and moderators of the relation between child maltreatment (CM) and suicidal ideation (SI) in adolescent psychiatric inpatients. The sample included 185 adolescents (71.4% female; 84% White) admitted to a psychiatric inpatient unit. Participants completed self-report measures assessing cognitive errors, negative cognitive triad, substance related problems, and SI. Participants and their parents completed a semi-structured diagnostic interview assessing CM history. In this clinical sample, we found that child maltreatment was associated with suicidal ideation only for youth with current substance abuse problems, indicating moderation. Contrary to predictions, substance related problems did not mediate the association between child maltreatment and adolescent SI. Further, cognitive errors and negative cognitive triad did not mediate or moderate the association between CM and SI. However, there were significant unique effects for both cognitive errors and negative cognitive triad on SI, suggesting that adolescents with more severe cognitive distortions report greater SI, regardless of CM history. Clinically, results suggest that practitioners should carefully screen for and address any substance misuse among victims of maltreatment to prevent clinically significant SI. Study results also suggest that interventions that incorporate cognitive restructuring may help decrease risk for severe SI in adolescent clinical samples in general.

  12. Effect of Yarn Distortion on the Mechanical Properties of Fiber-Bar Composites Reinforced by Three-Dimensional Weaving

    Science.gov (United States)

    Kang, Huairong; Shan, Zhongde; Zang, Yong; Liu, Feng

    2016-04-01

    A meso-structure model of fiber-bar composites reinforced by three-dimensional weaving (FBCR3DW) is proposed. Optical microscopy images of the preform structure revealed that the fibers along the circumference of the yarn cross-weave were twisted randomly due to alternating yarn winding on either side of the fiber bars during the manufacturing process. Sections of the cross-woven yarn were divided into five regions based on the twist characteristics. Stochastic function theory was used to describe the twist characteristics and to calculate the compliance tensor for each twisted yarn region. The twist characteristics and compliance tensor of each region were then introduced into a finite element model to calculate the elastic properties of the twisted yarn and FBCR3DW; unidirectional tensile stress-strain curves were generated based on the Tsai-Wu failure criterion. Several FBCR3DW specimens with randomly twisted yarns inside the weave structure were used in experimental tests. Our numerical results were in good agreement with the experimental values. Yarn distortion had a significant effect on the elastic properties and axial tensile strength of the yarn; specifically, the influence of yarn distortion on the transverse elastic modulus and transverse shear modulus of FBCR3DW was severe, whereas only a slight effect occurred with regard to the other elastic constants and unidirectional tensile properties. Thus, the proposed method provides an effective reference for modeling fiber composites with a weave structure.

  13. Matching theory

    CERN Document Server

    Lovász, László

    2009-01-01

    This book surveys matching theory, with an emphasis on connections with other areas of mathematics and on the role matching theory has played, and continues to play, in the development of some of these areas. Besides basic results on the existence of matchings and on the matching structure of graphs, the impact of matching theory is discussed by providing crucial special cases and nontrivial examples on matroid theory, algorithms, and polyhedral combinatorics. The new Appendix outlines how the theory and applications of matching theory have continued to develop since the book was first publish

  14. Making sense, making good, or making meaning? Cognitive distortions as targets of change in offender treatment.

    Science.gov (United States)

    Friestad, Christine

    2012-05-01

    Most structured sex-offender programs are based on a cognitive-behavioural model of behaviour change. Within this overarching theoretical paradigm, extensive use of cognitive distortions is seen as a central core symptom among sex offenders. However, the literature on cognitive distortions lacks a clear and consistent definition of the term. It is unclear whether cognitive distortions are consciously employed excuses or unconscious processes serving to protect the offender from feelings of guilt or shame. In this article, the dominant cognitive-behavioural interpretation of cognitive distortions is contrasted with two alternative interpretations. One is based on an attributional perspective and the notion of attributional biases. The other explanation is based on a narrative approach focusing on the action elements of cognitive distortions, that is, as something people do rather than something they have. Clinical implications of these alternative conceptualizations are discussed and illustrated throughout by a case example.

  15. Carrier Distortion in Hysteretic Self-Oscillating Class-D Audio Power

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod; Andersen, Michael A. E.

    2009-01-01

    An important distortion mechanism in hysteretic self-oscillating (SO) class-D (switch mode) power amplifiers-–carrier distortion-–is analyzed and an optimization method is proposed. This mechanism is an issue in any power amplifier application where a high degree of proportionality between input...... and output is required, such as in audio power amplifiers or xDSL drivers. From an average-mode point of view, carrier distortion is shown to be caused by nonlinear variation of the hysteretic comparator input average voltage with the output average voltage. This easily causes total harmonic distortion...... figures in excess of 0.1–0.2%, inadequate for high-quality audio applications. Carrier distortion is shown to be minimized when the feedback system is designed to provide a triangular carrier (sliding) signal at the input of a hysteretic comparator. The proposed optimization method is experimentally...

  16. Efficient Simulation of Welding Distortion in Large Structures and Its Reduction by Jig Constraints

    Science.gov (United States)

    Ma, Ninshu; Huang, Hui

    2017-10-01

    Two large construction machinery structures were welded separately with and without jig constraints. The welding distortion of the entire structure was measured by a 3D coordinate measuring system and simulated by elastic FEM using the inherent deformation method. To obtain an accurate inherent deformation, a thermal elastoplastic FE analysis of simple one-side fillet joints with and without jig constraints was performed. Efficient simulation of welding distortion in large structures was accomplished by applying inherent deformation in a localized region, and the effect of jig constraint on the reduction of welding distortion was clarified. The computation of inherent deformation, the weld zone definition and the conversion of inherent deformation into inherent strain were automated. Measured and computed welding distortions in large structures had a good correspondence with respect to both tendency and magnitude. Further investigation of jig configuration was performed for enhanced reduction of welding distortion. Alternative controlling techniques for common welded structures were also addressed.

  17. Computer versus paper-and-pencil administration mode and response distortion in noncognitive selection tests.

    Science.gov (United States)

    Potosky, D; Bobko, P

    1997-04-01

    This study examined the strength of the relationship between computerized and paper-and-pencil noncognitive selection measures. The tendency to engage in response distortion across these 2 modes was also assessed. The raw cross-mode correlations exceeded .90 for all of the substantive selection scales studied. Indeed, latent cross-mode correlations were estimated to be 1.0 for all of these scales. Mean score comparisons of 1 of the response distortion measures (i.e., the Balanced Inventory of Desirable Responding) suggested that response distortion in the computer-administration mode was significantly greater than response distortion observed with a paper-and-pencil format. However, administration mode did not influence scores on another measure of direct response distortion or any of the substantive selection measures administered.

  18. Experimental Study of the Redistribution of Welding Distortion According to the Partial Removal of Welded Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Rae; Wang, Chao; Kim, Jae Woong [Yeungnam University, Kyungsan (Korea, Republic of)

    2015-07-15

    During the welding process, welding distortion is caused by the non-uniformity of the temperature distribution in the weldment. Welding distortion is redistributed because the residual stress and rigidity change according to the removal of the welded structure. In shipbuilding in particular, this phenomenon may be observed during the cutting process of lugs that are attached to blocks for transfer. The redistribution of welding distortion also causes problems, such as damage to the cutting tool. The aim of this study is to experimentally analyze the redistribution of welding distortion because of the partial removal of the welded structure. In the experiments conducted in this study, fillet welding and cutting were performed, and longitudinal bending and angular distortion in the welded structures were then investigated and analyzed.

  19. Polarization-independent distortion corrector fabricated using polymer-dispersed liquid crystals.

    Science.gov (United States)

    Hsieh, Chia-Ting; Ding, Pin-Ruei; Liao, Chen-Hao; Su, Wei-Chia; Huang, Chi-Yen; Lin, Chi-Huang; Lo, Kuang-Yao; Tien, Ching-Jui; Hsu, Tzu-Fung

    2014-01-20

    We demonstrate a polarization-independent distortion corrector fabricated using a polymer-dispersed liquid crystal (PDLC) cell placed on the intermediate image plane of an optical system. At low voltage, a hazy PDLC cell scatters the incident rays and redirects the off-axis propagated chief ray. The chief ray approaches the principal point of the lens element, thereby decreasing image distortion. At high voltage, the PDLC cell becomes transparent, thereby restoring the image distortion. The PDLC-based distortion corrector is an easy-to-fabricate universal device that can be applied to various optical systems. With a large lens diameter, the distortion of a PDLC-corrected image is approximately 1/5 of that of an uncorrected image.

  20. The relationship between tinnitus pitch and parameters of audiometry and distortion product otoacoustic emissions.

    Science.gov (United States)

    Keppler, H; Degeest, S; Dhooge, I

    2017-11-01

    Chronic tinnitus is associated with reduced auditory input, which results in changes in the central auditory system. This study aimed to examine the relationship between tinnitus pitch and parameters of audiometry and distortion product otoacoustic emissions. For audiometry, the parameters represented the edge frequency of hearing loss, the frequency of maximum hearing loss and the frequency range of hearing loss. For distortion product otoacoustic emissions, the parameters were the frequency of lowest distortion product otoacoustic emission amplitudes and the frequency range of reduced distortion product otoacoustic emissions. Sixty-seven patients (45 males, 22 females) with subjective chronic tinnitus, aged 18 to 73 years, were included. No correlation was found between tinnitus pitch and parameters of audiometry and distortion product otoacoustic emissions. However, tinnitus pitch fell mostly within the frequency range of hearing loss. The current study seems to confirm the relationship between tinnitus pitch and the frequency range of hearing loss, thus supporting the homeostatic plasticity model.

  1. Efficient Simulation of Welding Distortion in Large Structures and Its Reduction by Jig Constraints

    Science.gov (United States)

    Ma, Ninshu; Huang, Hui

    2017-11-01

    Two large construction machinery structures were welded separately with and without jig constraints. The welding distortion of the entire structure was measured by a 3D coordinate measuring system and simulated by elastic FEM using the inherent deformation method. To obtain an accurate inherent deformation, a thermal elastoplastic FE analysis of simple one-side fillet joints with and without jig constraints was performed. Efficient simulation of welding distortion in large structures was accomplished by applying inherent deformation in a localized region, and the effect of jig constraint on the reduction of welding distortion was clarified. The computation of inherent deformation, the weld zone definition and the conversion of inherent deformation into inherent strain were automated. Measured and computed welding distortions in large structures had a good correspondence with respect to both tendency and magnitude. Further investigation of jig configuration was performed for enhanced reduction of welding distortion. Alternative controlling techniques for common welded structures were also addressed.

  2. Analyzing Reaction Rates with the Distortion/Interaction‐Activation Strain Model

    Science.gov (United States)

    2017-01-01

    Abstract The activation strain or distortion/interaction model is a tool to analyze activation barriers that determine reaction rates. For bimolecular reactions, the activation energies are the sum of the energies to distort the reactants into geometries they have in transition states plus the interaction energies between the two distorted molecules. The energy required to distort the molecules is called the activation strain or distortion energy. This energy is the principal contributor to the activation barrier. The transition state occurs when this activation strain is overcome by the stabilizing interaction energy. Following the changes in these energies along the reaction coordinate gives insights into the factors controlling reactivity. This model has been applied to reactions of all types in both organic and inorganic chemistry, including substitutions and eliminations, cycloadditions, and several types of organometallic reactions. PMID:28447369

  3. Analyzing Reaction Rates with the Distortion/Interaction-Activation Strain Model.

    Science.gov (United States)

    Bickelhaupt, F Matthias; Houk, Kendall N

    2017-08-14

    The activation strain or distortion/interaction model is a tool to analyze activation barriers that determine reaction rates. For bimolecular reactions, the activation energies are the sum of the energies to distort the reactants into geometries they have in transition states plus the interaction energies between the two distorted molecules. The energy required to distort the molecules is called the activation strain or distortion energy. This energy is the principal contributor to the activation barrier. The transition state occurs when this activation strain is overcome by the stabilizing interaction energy. Following the changes in these energies along the reaction coordinate gives insights into the factors controlling reactivity. This model has been applied to reactions of all types in both organic and inorganic chemistry, including substitutions and eliminations, cycloadditions, and several types of organometallic reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  4. Gravitation as a Plastic Distortion of the Lorentz Vacuum

    CERN Document Server

    Fernández, Virginia Velma

    2010-01-01

    Addressing graduate students and researchers in theoretical physics and mathematics, this book presents a new formulation of the theory of gravity. In the new approach the gravitational field has the same ontology as the electromagnetic, strong, and weak fields. In other words it is a physical field living in Minkowski spacetime. Some necessary new mathematical concepts are introduced and carefully explained. Then they are used to describe the deformation of geometries, the key to describing the gravitational field as a plastic deformation of the Lorentz vacuum. It emerges after further analysis that the theory provides trustworthy energy-momentum and angular momentum conservation laws, a feature that is normally lacking in General Relativity.

  5. RELAP-7 Theory Manual

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Ray Alden [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zou, Ling [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Hongbin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Peterson, John William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Martineau, Richard Charles [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kadioglu, Samet Yucel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andrs, David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    This document summarizes the physical models and mathematical formulations used in the RELAP-7 code. In summary, the MOOSE based RELAP-7 code development is an ongoing effort. The MOOSE framework enables rapid development of the RELAP-7 code. The developmental efforts and results demonstrate that the RELAP-7 project is on a path to success. This theory manual documents the main features implemented into the RELAP-7 code. Because the code is an ongoing development effort, this RELAP-7 Theory Manual will evolve with periodic updates to keep it current with the state of the development, implementation, and model additions/revisions.

  6. Topos theory

    CERN Document Server

    Johnstone, PT

    2014-01-01

    Focusing on topos theory's integration of geometric and logical ideas into the foundations of mathematics and theoretical computer science, this volume explores internal category theory, topologies and sheaves, geometric morphisms, other subjects. 1977 edition.

  7. Designing a Classification System for Internet Offenders: Doing Cognitive Distortions

    Science.gov (United States)

    Hundersmarck, Steven F.; Durkin, Keith F.; Delong, Ronald L.

    2007-01-01

    Televised features such as NBC's "To Catch a Predator" have highlighted the growing problem posed by Internet sexual predators. This paper reports on the authors' attempts in designing a classification system for Internet offenders. The classification system was designed based on existing theory, understanding the nature of Internet offenders and…

  8. Labor Market Distortions in Côte d'Ivoire:

    DEFF Research Database (Denmark)

    Kristensen, Nicolai; Verner, Dorte

    2008-01-01

    may influence employment through tenure but do not seem to influence wages directly except for vulnerable minorities that seem protected by unions. Establishment-size wage effects are pronounced and highest for white-collar workers. This may be explained by the efficiency wage theory, so that, even...

  9. Grounded theory

    OpenAIRE

    Harris, Tina

    2014-01-01

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate app...

  10. Using Developmental Theory: When Not to Play Telephone Games

    Directory of Open Access Journals (Sweden)

    Sara Nora Ross

    2008-06-01

    Full Text Available As a powerful way to help understand the behaviors of people and socialgroupings of all kinds, developmental stage theory attracts attention and use outside ofpurely academic environments. These uses take the form of written materials and manykinds of interventions. The level of accuracy of developmental theory informationgenerated and used outside of academe demonstrates wide variety. This variety isreflected in materials and interventions. The information used in materials andinterventions becomes increasingly distorted as it becomes further removed from originaltheoretical sources. This has major implications for the ethics and expertise issues that areinherent in applied developmental theory. A classification scheme of information-usebehaviors, many of which contribute to distortion processes, is used to code actual casesof creating and disseminating distorted developmental theory information, invoking themetaphor of telephone games. Case evidence indicates that casual, illustrative figures in a2006 book by Wilber were used by others for various serious and theoretical purposes,and resulted in major distortions of developmental theory. Wilber’s figures representproblematic issues and errors, including distortion of theory, if they are used—as theyindeed were—for any purpose more serious than his original purpose. Stemming fromthose issues and errors, a highly distorted picture of cognitive development and a pseudoversionof Commons and Richards’ Model of Hierarchical Complexity theory emerged,telephone game-like, in the cases discussed. Errors were widely propagated on theinternet. Because outside of academe, specialized expertise in developmental theory isdifficult to acquire, the sub-field of applied developmental theory requires not onlyaccurate information but also strong communication ethics to govern behaviors ofinformation providers. Such providers need to protect themselves at the same time theyprotect and inform consumers of

  11. Fifty years of Szigeti's dielectric theory – A review

    Indian Academy of Sciences (India)

    However, the treatment of Born and Huang was qualitative. Lundquist [19] used the Heitler–London approach to evaluate the overlap distortion moment for NaCl. Dick and Overhauser [20] reexamined Szigeti's theory. They pointed out that apart from the electronic polarization and polarization due to displacement of ions.

  12. Progress in all-order breakup reaction theories

    Indian Academy of Sciences (India)

    Progress in breakup reaction theories, like the distorted wave Born approximation, the continuum discretized coupled channels method and the dynamical eikonal approximation, is brought into focus. The need to calculate exclusive reaction observables and the utility of benchmark tests as arbitrators of theoretical models ...

  13. First-principles investigations of homogeneous lattice-distortive strain and shuffles in Ni sub 2 MnGa

    CERN Document Server

    Zayak, A T; Enkovaara, J A; Ayuela, A; Nieminen, R M

    2003-01-01

    A series of first-principles calculations were performed for ferromagnetic Ni sub 2 MnGa using density functional theory and PAW potentials. Theoretically, a tetragonal crystal structure homogeneous lattice-distortive strain is stabilized around c/a = 0.94 with respect to the L2 sub 1 structure when, in addition, modulation shuffles with a period of five atomic planes are taken into account. This is in agreement with the observed structures in experimental works. The modulation appears to be critically important for stability of the tetragonal structure with c/a < 1. Here, we report a new feature which is related to the optimum amplitudes of the modulation in different atomic planes. Related to this are systematic changes in the minority spin density of states near the Fermi surface, like in the formalism of a pseudo-gap.

  14. Monitoring carboplatin ototoxicity with distortion-product otoacoustic emissions in children with retinoblastoma

    Science.gov (United States)

    Bhagat, Shaum P.; Bass, Johnnie K.; White, Stephanie T.; Qaddoumi, Ibrahim; Wilson, Matthew W.; Wu, Jianrong; Rodriguez-Galindo, Carlos

    2016-01-01

    Objective Carboplatin is a common chemotherapy agent with potential ototoxic side effects that is used to treat a variety of pediatric cancers, including retinoblastoma. Retinoblastoma is a malignant tumor of the retina that is usually diagnosed in young children. Distortion-product otoacoustic emission tests offer an effective method of monitoring for ototoxicity in young children. This study was designed to compare measurements of distortion-product otoacoustic emissions obtained before and after several courses of carboplatin chemotherapy in order to examine if (a) mean distortion-product otoacoustic emission levels were significantly different; and (b) if criterion reductions in distortion-product otoacoustic emission levels were observed in individual children. Methods A prospective repeated measures study. Ten children with a median age of 7.6 months (range, 3–72 months) diagnosed with unilateral or bilateral retinoblastoma were examined. Distortion-product otoacoustic emissions were acquired from both ears of the children with 65/55 dB SPL primary tones (f2= 793–7996 Hz) and a frequency resolution of 3 points/octave. Distortion-product otoacoustic emission levels in dB SPL were measured before chemotherapy treatment (baseline measurement) and after 3–4 courses of chemotherapy (interim measurement). Comparisons were made between baseline and interim distortion-product otoacoustic emission levels (collapsed across ears). Evidence of ototoxicity was based on criterion reductions (≥ 6 dB) in distortion-product otoacoustic emission levels. Results Significant differences between baseline and interim mean distortion-product otoacoustic emission levels were only observed at f2=7996 Hz. Four children exhibited criterion reductions in distortion-product otoacoustic emission levels. Conclusions Mean distortion-product otoacoustic emission levels at most frequencies were not changed following 3–4 courses of carboplatin chemotherapy in children with

  15. Distortion product otoacoustic emissions in young adult and geriatric cats.

    Science.gov (United States)

    Strain, George M; McGee, Kain A

    2017-03-01

    Recordings of distortion product otoacoustic emissions (DPOAEs) were taken from 15 geriatric cats (mean age ± standard deviation, SD, 13.6 ± 2.7 years; range 10.2-19.4 years) and 12 young adult control cats (mean ± SD 4.6 ± 0.5 years; range 3.4-5 years) to identify frequency-specific age-related changes in cochlear responses. Recordings were performed for primary frequencies from 2 to 12 kHz in 2 kHz increments. Cats were considered to be geriatric > 11.9 ± 1.9 years of age. Brainstem auditory evoked response (BAER) recordings were also made for subjective comparison with DPOAE responses. No differences in DPOAE response amplitudes were observed at any tested frequency in geriatric cats compared to control cats, reflecting an apparent absence of loss of cochlear outer hair cells along the length of the cochlea. No linear regression relationships were found for DPOAE response amplitude versus age in geriatric cats, despite the progressive nature of age-related hearing loss in other species. The absence of reductions in response at any of the tested frequencies in cats within the age span where cats are considered to be geriatric indicates that age-related hearing loss, if it does develop in cats, begins later in the life span of cats than in dogs or human beings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Analysis of angular reading distortions of photographic images.

    Science.gov (United States)

    Codarin, Gabriela F; Felicio, Lilian R; Coelho, Daniel M; Oliveira, Anamaria S

    2012-01-01

    Although photogrammetry is a widespread technique in the health field, despite of the methodological efforts distortions in the angular readings of the images are common. To measure the error of angular measurements in photo images with different digital resolutions in an object with pre-determined angles. We used a rubber ball with 52 cm in circumference. The object was previously marked with angles of 10°, 30°, 60° and 90° degrees. The photographic records were performed with the focal axis of the camera perpendicular and three meters away from the object, without the use of optical zoom and a resolution of 3, 5 and 10 Megapixels (Mp). All photographic records were stored and a previously trained experimenter using the computer program ImageJ analyzed the angular values of each photo. The measurements were performed twice within a fifteen-days interval. Subsequently, we calculated the accuracy, relative error and error in degrees values, precision and the Intraclass Correlation Coefficient (ICC). When analyzing the angle of 10°, the average accuracy of measurements was higher for those records of 3 Mp resolution compared to 5 and 10 Mp resolutions. The ICC was considered excellent for all resolutions. With regards to the analyzed angles in photographic records, it was possible to verify that the 90-degree angle photographs were more accurate, had lower relative error and error in degrees, and were more precise, regardless of image resolution. The photographs records that were taken with a 3 Mp resolution provided great accuracy and precision measurements and lower errors values, suggesting to be the proper resolution to generate image of angles of 10º and 30º.

  17. Variation of distortion product otoacoustic emissions with furosemide injection.

    Science.gov (United States)

    Mills, D M; Rubel, E W

    1994-06-15

    Cochlear function was monitored in adult gerbils using distortion product otoacoustic emissions (DPOAE) during intraperitoneal injection of furosemide. All stimulus parameters were varied independently over a wide range, the stimulus frequencies f1 and f2 from 1 to 16 kHz, and the stimulus levels L1 and L2 from 20 to 80 dB SPL. The observed emissions at 2f1-f2 and 3f1-2f2 could be considered to be made up of two distinct components: (1) an 'active' source which depended in a complex way on the stimulus frequencies and levels, which was dominant at low and moderate stimulus levels, and which, by definition, was eliminated by sufficient furosemide intoxication; and (2) a 'passive' source which was essentially the same at all frequencies, with a level dependence given approximately by a simple power law distribution. The change from the active to the passive source was usually accompanied by an abrupt shift in emission phase angle. A simple summation model was shown to account for the observed form of this transition. The amount of the decrease in 2f1-f2 emission amplitude after furosemide injection was approximately independent of frequency and consistent for the middle frequency ratios and intensity levels (f2/f1 approximately equal to 1.3, L1 x L2 approximately equal to 55 x 50 dB SPL). It was concluded that the combination of DPOAE with furosemide injection can usefully be employed as a probe of active cochlear mechanics.

  18. Quantifying and Reducing Posture-Dependent Distortion in Ballistocardiogram Measurements

    Science.gov (United States)

    Javaid, Abdul Q.; Wiens, Andrew D.; Fesmire, N. Forrest; Weitnauer, Mary A.; Inan, Omer T.

    2015-01-01

    Ballistocardiography is a non-invasive measurement of the mechanical movement of the body caused by cardiac ejection of blood. Recent studies have demonstrated that ballistocardiogram (BCG) signals can be measured using a modified home weighing scale, and used to track changes in myocardial contractility and cardiac output. With this approach, the BCG can potentially be used both for preventive screening and for chronic disease management applications. However, for achieving high signal quality, subjects are required to stand still on the scale in an upright position for the measurement; the effects of intentional (for user comfort) or unintentional (due to user error) modifications in the position or posture of the subject during the measurement have not been investigated in the existing literature. In this study, we quantified the effects of different standing and seated postures on the measured BCG signals, and on the most salient BCG-derived features compared to reference standard measurements (e.g., impedance cardiography). We determined that the standing upright posture led to the least distorted signals as hypothesized, and that the correlation between BCG-derived timing interval features (R-J interval) and the pre-ejection period, PEP (measured using ICG), decreased significantly with impaired posture or sitting position. We further implemented two novel approaches to improve the PEP estimates from other standing and sitting postures, using system identification and improved J-wave detection methods. These approaches can improve the usability of standing BCG measurements in unsupervised settings (i.e. the home), by improving the robustness to non-ideal posture, as well as enabling high quality seated BCG measurements. PMID:26058064

  19. Distortion Product Otoacoustic Emissions in acute acoustic trauma.

    Science.gov (United States)

    Oeken, Jens

    1998-01-01

    Acute acoustic traumas are caused by exposure to extremely high noise levels ranging from milliseconds to several hours' duration. In pure tone audiometry they range from the C5 dip to basomediocochlear sensorineural hearing loss. Their pathogenesis is assumed to consist of micromechanical-traumatic and biochemical-metabolic damage to the outer hair cells. In order to establish the changes to the DPOAE (distortion products of otoacoustic emissions), 17 patients were examined after sustaining acute acoustic trauma. The causes included firework explosions, anti-tank rocket launchers, vehicle tyre bursting, rock concerts, hand-gun shots, sub-machine gun fire, hand grenade explosion, exploding car battery. The pure tone audiogram, tympanogram, tinnitus maskability and DPOAE (both DP-gram and growth rate in various frequencies) were determined in all patients. If the event had occurred some time ago, measurements were taken only once; in acute cases measurements were repeated at different times. In nine patients with persistent hearing impairment, clear DPs were found in the unaffected frequencies but were completely absent in the affected frequency range. Four of these patients were unilaterally and two patients were bilaterally affected; three patients had a different (not noise-induced) hearing loss on the opposite side. In eight patients with regressive hearing loss, DPs were by contrast detectable throughout the entire frequency range, their amplitudes only rising slightly as hearing recovered. Of these eight patients, three were unilaterally and five bilaterally affected. DPOAE seem to indicate the likelihood of recovery of hearing threshold after an acute acoustic trauma. In cases with DPs completely absent in the affected frequency range, the prognosis seems to be much worse than in cases with present DPs in the frequency range of hearing.

  20. Higher Education: Reputational Effects, Distorted Signaling and Propitious Selection

    Directory of Open Access Journals (Sweden)

    Elena V. Savitskaya

    2017-03-01

    Full Text Available In the paper the authors attempt to underpin the hypothesis that under certain conditions a propitious selection may take place on the higher education market. It is a phenomenon when brand universities automatically reproduce their positive reputation without improving the quality of teaching due to influx of talented entrants. The authors apply econometric modelling and regression analysis based on survey of first-year students from Moscow to demonstrate that graduates with high USE marks really prefer to choose among brand universities; moreover, they appreciate a possibility to obtain a prestigious diploma even more than that of acquiring a particular profession. However, entrants do not possess full information about the quality of teaching in a particular university. The analysis presented in the paper shows that university rankings do not contribute to overcoming of this information asymmetry, since they transmit distorted signals caused by the methodology of ranking. The rankings, first of all, accentuate academic activity of teachers rather than educational process and interaction with students. For this reason, higher schools often adopt such a strategy to meet the ranking criteria as much as possible; they also tend to improve namely these indicators disregarding the other to become a leader. As a result, brand universities may surpass ordinary universities not due to rendering educational services of higher quality but due to selection of best entrants and peer-effects. These factors allow them to have excellent graduates, thus maintain positive reputation in employers’ opinion and simultaneously raise the brand value by advancing in a ranking.

  1. The evolution of sex ratio distorter suppression affects a 25 cM genomic region in the butterfly Hypolimnas bolina.

    Directory of Open Access Journals (Sweden)

    Emily A Hornett

    2014-12-01

    Full Text Available Symbionts that distort their host's sex ratio by favouring the production and survival of females are common in arthropods. Their presence produces intense Fisherian selection to return the sex ratio to parity, typified by the rapid spread of host 'suppressor' loci that restore male survival/development. In this study, we investigated the genomic impact of a selective event of this kind in the butterfly Hypolimnas bolina. Through linkage mapping, we first identified a genomic region that was necessary for males to survive Wolbachia-induced male-killing. We then investigated the genomic impact of the rapid spread of suppression, which converted the Samoan population of this butterfly from a 100:1 female-biased sex ratio in 2001 to a 1:1 sex ratio by 2006. Models of this process revealed the potential for a chromosome-wide effect. To measure the impact of this episode of selection directly, the pattern of genetic variation before and after the spread of suppression was compared. Changes in allele frequencies were observed over a 25 cM region surrounding the suppressor locus, with a reduction in overall diversity observed at loci that co-segregate with the suppressor. These changes exceeded those expected from drift and occurred alongside the generation of linkage disequilibrium. The presence of novel allelic variants in 2006 suggests that the suppressor was likely to have been introduced via immigration rather than through de novo mutation. In addition, further sampling in 2010 indicated that many of the introduced variants were lost or had declined in frequency since 2006. We hypothesize that this loss may have resulted from a period of purifying selection, removing deleterious material that introgressed during the initial sweep. Our observations of the impact of suppression of sex ratio distorting activity reveal a very wide genomic imprint, reflecting its status as one of the strongest selective forces in nature.

  2. The evolution of sex ratio distorter suppression affects a 25 cM genomic region in the butterfly Hypolimnas bolina.

    Science.gov (United States)

    Hornett, Emily A; Moran, Bruce; Reynolds, Louise A; Charlat, Sylvain; Tazzyman, Samuel; Wedell, Nina; Jiggins, Chris D; Hurst, Greg D D

    2014-12-01

    Symbionts that distort their host's sex ratio by favouring the production and survival of females are common in arthropods. Their presence produces intense Fisherian selection to return the sex ratio to parity, typified by the rapid spread of host 'suppressor' loci that restore male survival/development. In this study, we investigated the genomic impact of a selective event of this kind in the butterfly Hypolimnas bolina. Through linkage mapping, we first identified a genomic region that was necessary for males to survive Wolbachia-induced male-killing. We then investigated the genomic impact of the rapid spread of suppression, which converted the Samoan population of this butterfly from a 100:1 female-biased sex ratio in 2001 to a 1:1 sex ratio by 2006. Models of this process revealed the potential for a chromosome-wide effect. To measure the impact of this episode of selection directly, the pattern of genetic variation before and after the spread of suppression was compared. Changes in allele frequencies were observed over a 25 cM region surrounding the suppressor locus, with a reduction in overall diversity observed at loci that co-segregate with the suppressor. These changes exceeded those expected from drift and occurred alongside the generation of linkage disequilibrium. The presence of novel allelic variants in 2006 suggests that the suppressor was likely to have been introduced via immigration rather than through de novo mutation. In addition, further sampling in 2010 indicated that many of the introduced variants were lost or had declined in frequency since 2006. We hypothesize that this loss may have resulted from a period of purifying selection, removing deleterious material that introgressed during the initial sweep. Our observations of the impact of suppression of sex ratio distorting activity reveal a very wide genomic imprint, reflecting its status as one of the strongest selective forces in nature.

  3. Modified Theories of Gravitation behind the Spacetime Deformation

    Directory of Open Access Journals (Sweden)

    Gagik Ter-Kazarian

    2015-01-01

    Full Text Available In the framework of proposed theory of spacetime deformation/distortion, we have a way to deform the spacetime through a nontrivial choice of the distortion-complex, displaying different connections, which may reveal different post-Riemannian spacetime structures as corollary. We extend this theory to address, in particular, the gauge model of the most general metric-affine gravity carrying both nontrivial torsion and nonmetricity. This model is constructed in the framework of the first order Lagrangian expressed in terms of the gauge potentials and their first derivatives. The equations of the standard theory, which have no propagating modes for torsion, can be equivalently replaced in modified framework by the modified equations, which in the limit of reducing the affine group leads to the modified Einstein-Cartan theory with dynamical torsion and beyond. In testing the modified framework for various particular cases, we use the Lagrange multipliers for extinguishing nonmetricity and torsion.

  4. Ring theory

    CERN Document Server

    Rowen, Louis H

    1991-01-01

    This is an abridged edition of the author's previous two-volume work, Ring Theory, which concentrates on essential material for a general ring theory course while ommitting much of the material intended for ring theory specialists. It has been praised by reviewers:**""As a textbook for graduate students, Ring Theory joins the best....The experts will find several attractive and pleasant features in Ring Theory. The most noteworthy is the inclusion, usually in supplements and appendices, of many useful constructions which are hard to locate outside of the original sources....The audience of non

  5. Atomic theories

    CERN Document Server

    Loring, FH

    2014-01-01

    Summarising the most novel facts and theories which were coming into prominence at the time, particularly those which had not yet been incorporated into standard textbooks, this important work was first published in 1921. The subjects treated cover a wide range of research that was being conducted into the atom, and include Quantum Theory, the Bohr Theory, the Sommerfield extension of Bohr's work, the Octet Theory and Isotopes, as well as Ionisation Potentials and Solar Phenomena. Because much of the material of Atomic Theories lies on the boundary between experimentally verified fact and spec

  6. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  7. Number theory via Representation theory

    Indian Academy of Sciences (India)

    2014-11-09

    Number theory via Representation theory. Eknath Ghate. November 9, 2014. Eightieth Annual Meeting, Chennai. Indian Academy of Sciences1. 1. This is a non-technical 20 minute talk intended for a general Academy audience.

  8. Optimal correction of distortion for high-angular-resolution images: Application to GeMS data

    Science.gov (United States)

    Bernard, A.; Neichel, B.; Mugnier, L. M.; Fusco, T.

    2018-01-01

    Whether ground based or space based, any optical instrument suffers from some amount of optical geometric distortion. Recently, the diffraction-limited image quality afforded by space-based telescopes and by instruments corrected with adaptive optics on ground-based telescope has increased the relative importance of the error terms induced by optical distortions. In particular, the variable distortion in multi-conjugate adaptive optics (MCAO) data limits the astrometric and photometric accuracy of such high-resolution instruments. These phenomena have become a critical issue for high-precision studies. We present in this paper an optimal method of distortion correction for high-angular-resolution images. Based on prior knowledge of the static distortion, the method aims to correct the dynamic distortion for each observation set and each frame. The method follows an inverse problem approach based on the work by Gratadour, Mugnier & Rouan on image re-centring, and we aim to generalize this to any kind of distortion mode. The complete formalism of a weighted least-squares minimization as well as a detailed characterization of the error budget are presented. In particular, we study the influence of different parameters such as the number of frames, the density of the field (sparse or crowed images), the noise level and the aliasing effect. Finally, we show the first application of the method on real observations collected with the Gemini MCAO instrument, GeMS/GSAOI. The performance of as well as the gain brought by this method are presented.

  9. Measuring cognitive distortions in pathological gambling: review and meta-analyses.

    Science.gov (United States)

    Goodie, Adam S; Fortune, Erica E

    2013-09-01

    There is broad agreement that cognitive distortions are an integral component of the development, maintenance, and treatment of pathological gambling. There is no authoritative catalog of the distortions that are observed more frequently in pathological gamblers than in others, but several instruments have been successfully developed that measure various distortions of interest, which are reviewed. All of the prominent instruments include measures of the illusion of control (perceiving more personal control over events than is warranted), and almost all include measures of gambler's fallacy (the belief that after a string of one event, such as a coin landing heads, an alternative event, such as the coin landing tails, becomes more likely). Beyond these two errors, there is scant consensus on relevant errors, and a wide variety has been studied. Meta-analyses were conducted on differences between PGs and non-PGs in scores on six published instruments that were developed to measure distortions in gamblers. All instruments reveal large effects using Hedge's g statistic, suggesting that the impact of distortions on PG is robust. Several subscales, assigned diverse names by scale authors, can be viewed as reflecting common distortions. Those judged to assess gambler's fallacy show evidence of more robust effects sizes than those that assess illusion of control. It is recommended that future research focus more specifically on the impact of particular distortions on gambling disorders. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  10. Distortion Correction in EPI Using an Extended PSF Method with a Reversed Phase Gradient Approach

    Science.gov (United States)

    In, Myung-Ho; Posnansky, Oleg; Beall, Erik B.; Lowe, Mark J.; Speck, Oliver

    2015-01-01

    In echo-planar imaging (EPI), such as commonly used for functional MRI (fMRI) and diffusion-tensor imaging (DTI), compressed distortion is a more difficult challenge than local stretching as spatial information can be lost in strongly compressed areas. In addition, the effects are more severe at ultra-high field (UHF) such as 7T due to increased field inhomogeneity. To resolve this problem, two EPIs with opposite phase-encoding (PE) polarity were acquired and combined after distortion correction. For distortion correction, a point spread function (PSF) mapping method was chosen due to its high correction accuracy and extended to perform distortion correction of both EPIs with opposite PE polarity thus reducing the PSF reference scan time. Because the amount of spatial information differs between the opposite PE datasets, the method was further extended to incorporate a weighted combination of the two distortion-corrected images to maximize the spatial information content of a final corrected image. The correction accuracy of the proposed method was evaluated in distortion-corrected data using both forward and reverse phase-encoded PSF reference data and compared with the reversed gradient approaches suggested previously. Further we demonstrate that the extended PSF method with an improved weighted combination can recover local distortions and spatial information loss and be applied successfully not only to spin-echo EPI, but also to gradient-echo EPIs acquired with both PE directions to perform geometrically accurate image reconstruction. PMID:25707006

  11. Automated detection method for architectural distortion areas on mammograms based on morphological processing and surface analysis

    Science.gov (United States)

    Ichikawa, Tetsuko; Matsubara, Tomoko; Hara, Takeshi; Fujita, Hiroshi; Endo, Tokiko; Iwase, Takuji

    2004-05-01

    As well as mass and microcalcification, architectural distortion is a very important finding for the early detection of breast cancer via mammograms, and such distortions can be classified into three typical types: spiculation, retraction, and distortion. The purpose of this work is to develop an automatic method for detecting areas of architectural distortion with spiculation. The suspect areas are detected by concentration indexes of line-structures extracted by using mean curvature. After that, discrimination analysis of nine features is employed for the classifications of true and false positives. The employed features are the size, the mean pixel value, the mean concentration index, the mean isotropic index, the contrast, and four other features based on the power spectrum. As a result of this work, the accuracy of the classification was 76% and the sensitivity was 80% with 0.9 false positives per image in our database in regard to spiculation. It was concluded that our method was effective in detectiong the area of architectural distortion; however, some architectural distortions were not detected accurately because of the size, the density, or the different appearance of the distorted areas.

  12. Practical analysis and mathematical modelling of harmonic distortions caused by electronic loads

    Energy Technology Data Exchange (ETDEWEB)

    Jabbar, R.A.; Akmal, M.; Qureshi, W.A.; Ahmad, A. [Rachna College of Engineering and Technology, Gujranwala (Pakistan); Qureshi, S.A. [Univ. of Engineering and Technology, Lahore (Pakistan)

    2007-07-01

    Power supply systems have no control over the currents that particular loads may draw upon, and standards in power quality tend to focus on maintaining supply voltage within certain limits. This study examined the impact of personal computers (PCs) connected to a single power supply on voltage and current waveforms. Total harmonic distortion in current and voltage was measured using a power quality analyzer. Distorted waveforms of current and voltage in time and frequency domains for the 23 personal computers were presented. Mathematical expressions were then developed using the data. The analysis demonstrated that voltage distortions increased with the addition of more PCs, while current distortions decreased. The power factor also increased when additional PCs were added. The study showed that there is a linear relationship between the number of PCs and the number of total voltage distortions. An approximate linear relationship between the number of PCs and the number of total current distortions was also observed. It was concluded that the model can be used to evaluate anticipated voltage distortions in power distribution networks as well as to improve performance and power quality. 14 refs., 2 tabs., 10 figs.

  13. The Analysis of the Relationship Between Interpersonal Cognitive Distortions and Aggression Responses of High School Students

    Directory of Open Access Journals (Sweden)

    Erol UĞUR

    2014-12-01

    Full Text Available The purpose of this study is to display the relationship between interpersonal cognitive distortions and aggression responses of high school students and to determine if how interpersonal cognitive distortions predict aggression level. The subjects of this study were 843 students who have been studying in 9th, 10th, 11th and 12th grads of high schools in Gaziantep. The data were collected by using three instruments, namely, ‘’Demographic Data Form’’, ‘’Interpersonal Cognitive Distortions Scale’’ (Hamamcı ve Büyüköztürk, 2003 and ‘’Aggression Scale’’ (Can, 2002 in this study. According to the results of this study; significant positive correlations were found between interpersonal cognitive distortions and aggression responses. It has been found out that the students having high interpersonal cognitive distortion level has higher points of all subscales of Aggression Responses Scale than students have low interpersonal cognitive distortion level. According to the results of multiple regression analysis, it is indicated that all subscales points of interpersonal cognitive distortions were significant predictors for student’s total aggression points

  14. Demand effects on positive response distortion by police officer applicants on the Revised NEO Personality Inventory.

    Science.gov (United States)

    Detrick, Paul; Chibnall, John T; Call, Cynthia

    2010-09-01

    Understanding and detecting response distortion is important in the high-demand circumstances of personnel selection. In this article, we describe positive response distortion on the Revised NEO Personality Inventory (NEO PI-R; Costa & McCrae, 1992) among police officer applicants under high and low demand conditions. Positive response distortion primarily reflected denial/minimization of Neuroticism and accentuation of traits associated with moralistic bias (Agreeableness and Conscientiousness). Validity of the NEO PI-R research validity scale, Positive Presentation Management, was weakly supported with respect to the Neuroticism domain only. Results will be useful in interpreting personality inventory results in the police personnel selection process.

  15. Response distortion in personality measurement: born to deceive, yet capable of providing valid self-assessments?

    Directory of Open Access Journals (Sweden)

    STEPHAN DILCHERT

    2006-09-01

    Full Text Available This introductory article to the special issue of Psychology Science devoted to the subject of “Considering Response Distortion in Personality Measurement for Industrial, Work and Organizational Psychology Research and Practice” presents an overview of the issues of response distortion in personality measurement. It also provides a summary of the other articles published as part of this special issue addressing social desirability, impression management, self-presentation, response distortion, and faking in personality measurement in industrial, work, and organizational settings.

  16. A Coherent Optical OFDM Communication System with Nonlinear Distortion Compensation in the Channel and Receiver

    Science.gov (United States)

    Asha, R. S.; Jayasree, V. K.

    2017-08-01

    A simple and low-cost scheme is proposed for reducing the distortions in the coherent optical orthogonal frequency-division multiplexing (CO-OFDM) system. The total wireless channel noise and the distortions in the receiver can be considered as an additive white Gaussian noise model and all distortions can be reduced using maximum likelihood sequence estimation (MLSE) equalizers. The performance of the CO-OFDM is analyzed for different fiber lengths and laser powers. Results show that the MLSE-equalized system can outperform with a higher Q-factor of 8 dB than conventional CO-OFDM system.

  17. An analytical approach to space charge distortions for time projection chambers

    CERN Document Server

    Rossegger, S; Riegler, W

    2010-01-01

    In a time projection chamber (TPC), the possible ion feedback and also the primary ionization of high multiplicity events result in accumulation of ionic charges inside the gas volume (space charge). This charge introduces electrical field distortions and modifies the cluster trajectory along the drift path, affecting the tracking performance of the detector. In order to calculate the track distortions due to an arbitrary space charge distribution in the TPC, novel representations of the Green's function for a TPC geometry were worked out. This analytical approach finally permits accurate predictions of track distortions due to an arbitrary space charge distribution by solving the Langevin equation.

  18. Study of distorted octahedral structure in 3d transition metal complexes using XAFS

    Science.gov (United States)

    Gaur, A.; Nitin Nair, N.; Shrivastava, B. D.; Das, B. K.; Chakrabortty, Monideepa; Jha, S. N.; Bhattacharyya, D.

    2018-01-01

    Distortion in octahedral structure of 3d transition metal complexes (Mn, Fe, Co, Ni, Cu, Zn) has been studied using XAFS showing divergent nature of Cu complex. EXAFS analysis showed elongated metal-oxygen bonds for Cu complex leading to more distorted structure. Derivative XANES spectrum at Cu K-edge exhibits splitting of main edge which is correlated to elongated Cu-O bond length. Using these coordination geometry around metal centers, theoretical XANES spectra have been generated and features observed have been correlated to the corresponding metals p-DOS. It has been shown that distorted octahedral field in Cu complex is responsible for splitting of p-DOS.

  19. Radial lens distortion correction with sub-pixel accuracy for X-ray micro-tomography.

    Science.gov (United States)

    Vo, Nghia T; Atwood, Robert C; Drakopoulos, Michael

    2015-12-14

    Distortion correction or camera calibration for an imaging system which is highly configurable and requires frequent disassembly for maintenance or replacement of parts needs a speedy method for recalibration. Here we present direct techniques for calculating distortion parameters of a non-linear model based on the correct determination of the center of distortion. These techniques are fast, very easy to implement, and accurate at sub-pixel level. The implementation at the X-ray tomography system of the I12 beamline, Diamond Light Source, which strictly requires sub-pixel accuracy, shows excellent performance in the calibration image and in the reconstructed images.

  20. Role(s) of anti-symmetrical background field in string theory; Role(s) du champ de fond antisymetrique en theorie des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Fidanza, St

    2003-11-15

    In the first chapter (titled: non-commutative D-branes), we show that the B anti-symmetrical background fields can be embedded in the non-commutativity of branes and can distort gauge theories that branes convey. We know how to describe this transformation in the Abelian case thanks to the Kontsevic quantification formula. Moreover this formula combined to the Seiberg-Witter transformation allows one to compute more rapidly the explicit terms. For the non-Abelian case the situation is less clear. In the chapter 2 (titled: non-Abelian M5-branes), we have tackled the issue of the fields of a packet of N M5-branes. The direct approach based on a 6 dimensional super-symmetric multiplets has led to a stunning dead end, we have not been able to reproduce the expected anomaly in N{sup 3}. We have presented in a unified manner different gauge theories. We have shown that we can get a number of freedom degrees in the magnitude order of N{sup 3} from computations based on geometrical configurations of M2 membranes. In the chapter 3 (titled: systematizing mirror symmetry) we have shown that if the presence of a non-trivial Neveu-Schwarz flux constrains the compactification manifold geometry to shift from the Calabi-Yau case, we can yet specify a mirror symmetry that mixes geometry and background fields. (A.C.)