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Sample records for voices singular vision

  1. Vision-Based Faint Vibration Extraction Using Singular Value Decomposition

    Directory of Open Access Journals (Sweden)

    Xiujun Lei

    2015-01-01

    Full Text Available Vibration measurement is important for understanding the behavior of engineering structures. Unlike conventional contact-type measurements, vision-based methodologies have attracted a great deal of attention because of the advantages of remote measurement, nonintrusive characteristic, and no mass introduction. It is a new type of displacement sensor which is convenient and reliable. This study introduces the singular value decomposition (SVD methods for video image processing and presents a vibration-extracted algorithm. The algorithms can successfully realize noncontact displacement measurements without undesirable influence to the structure behavior. SVD-based algorithm decomposes a matrix combined with the former frames to obtain a set of orthonormal image bases while the projections of all video frames on the basis describe the vibration information. By means of simulation, the parameters selection of SVD-based algorithm is discussed in detail. To validate the algorithm performance in practice, sinusoidal motion tests are performed. Results indicate that the proposed technique can provide fairly accurate displacement measurement. Moreover, a sound barrier experiment showing how the high-speed rail trains affect the sound barrier nearby is carried out. It is for the first time to be realized at home and abroad due to the challenge of measuring environment.

  2. Voice and Vision in The Poetry of Eavan Boland

    Directory of Open Access Journals (Sweden)

    Richard York

    2007-03-01

    Full Text Available Boland’s poetry seeks to reconcile political and personal, the moment and duration, self-knowledge –seen as an exteriorisation of the self– and narration. It is therefore fundamentally concerned with aesthetics, especially in visual art, which however it views as a form of division and hypostatization of the moment, while it also seeks to place the intense moment of vision in the processes of time by recurrent  images of transformation, anticipation, memory and loss; it is essentially elegiac, celebrating and lamenting the past and reflecting the constant presence of death within the everyday consciousness; hence the model of Vergil, and especially of the sixth book of the Aeneid,  and of Irish song.

  3. A greater voice for academic health sciences libraries: the Association of Academic Health Sciences Libraries' vision.

    Science.gov (United States)

    Bunting, Alison

    2003-04-01

    The founders of the Association of Academic Health Sciences Libraries (AAHSL) envisioned the development of a professional organization that would provide a greater voice for academic health sciences libraries, facilitate cooperation and communication with the Association of American Medical Colleges, and create a forum for identifying problems and solutions that are common to academic health sciences libraries. This article focuses on the fulfillment of the "greater voice" vision by describing action and leadership by AAHSL and its members on issues that directly influenced the role of academic health sciences libraries. These include AAHSL's participation in the work that led to the publication of the landmark report, Academic Information in the Academic Health Sciences Center: Roles for the Library in Information Management; its contributions to the recommendations of the Physicians for the Twenty-first Century: The GPEP Report; and the joint publication with the Medical Library Association of Challenge to Action: Planning and Evaluation Guidelines for Academic Health Sciences Libraries.

  4. Human Vision Inspired Based Image Illumination Enhancement by Using Local Singular Value Decomposition and Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Gholamreza Anbarjafari

    2015-01-01

    Full Text Available Recently, many computer vision applications are being inspired by human behavior, or human visual system. Also it is known that illumination issues have always been an important problem in many image processing applications. In this work we propose a new image illumination enhancement technique which is inspired from the human visual system behavior on illumination correction. The proposed technique uses local singular value decomposition (SVD and discrete wavelet transforms (DWT, inspired from the fact that human visual system equalizes a scene by disregarding the extreme illuminated areas. In other words, human brain uses local illumination enhancement and this localization is based on the extreme illuminations, e.g. existence or absence of too much light. In this technique, after dividing the image into several locals, each local is converted into the DWT domain and after updating the singular value matrix of the respective low-low subband, the local is reconstructed by using inverse DWT (IDWT. Combination of locals results in the equalized image. The technique is compared with the standard general histogram equalization (GHE and local histogram equalization (LHE. The experimental results are showing the superiority of the proposed method over the aforementioned techniques.

  5. Voices and Visions: Symbolic Convergences in the Oral Narratives of Filipino Comfort Women

    Directory of Open Access Journals (Sweden)

    Oscar Tantoco Serquiña, Jr.

    2015-12-01

    Full Text Available This paper analyzes oral narratives of 10 Filipino comfort women, who are members of the Liga ng mga Lolang Pilipina, or Lila Pilipina, an organization of victims and survivors of sexual slavery by Japanese military soldiers during the World War II in the Philippines. Guided by Ernest Bormann’s Symbolic Convergence Theory, this paper aims to describe the content, identify the salient structure, and determine the rhetorical vision in the oral narratives of Filipino comfort women. This paper argues that a pattern of characters, settings, and plotlines may be discerned from the oral narratives, and that these formal elements structurally and ideologically constitute the comfort women’s rhetorical vision of the future. This rhetorical vision is by and large a social drama that visualizes a just and warless society, renders the war as the major culprit in the destruction of Filipinos’ lives, and highlights the roles of Filipino comfort women and the youth in fighting militarization and in seeking peace and social justice in society.

  6. Removing Singularities

    CERN Document Server

    Elitzur, Shmuel; Rabinovici, Eliezer; Elitzur, Shmuel; Giveon, Amit; Rabinovici, Eliezer

    2003-01-01

    Big bang/crunch curvature singularities in exact CFT string backgrounds can be removed by turning on gauge fields. This is described within a family of {SL(2)xSU(2)xU(1)_x}/{U(1)xU(1)} quotient CFTs. Uncharged incoming wavefunctions from the ``whiskers'' of the extended universe can be fully reflected if and only if a big bang/crunch curvature singularity, from which they are scattered, exists. Extended BTZ-like singularities remain as long as U(1)_x is compact.

  7. Cosmological singularity

    CERN Document Server

    Belinski, V

    2009-01-01

    The talk at international conference in honor of Ya. B. Zeldovich 95th Anniversary, Minsk, Belarus, April 2009. The talk represents a review of the old results and contemporary development on the problem of cosmological singularity.

  8. Nonlinear singular vectors and nonlinear singular values

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel concept of nonlinear singular vector and nonlinear singular value is introduced, which is a natural generalization of the classical linear singular vector and linear singular value to the nonlinear category. The optimization problem related to the determination of nonlinear singular vectors and singular values is formulated. The general idea of this approach is demonstrated by a simple two-dimensional quasigeostrophic model in the atmospheric and oceanic sciences. The advantage and its applications of the new method to the predictability, ensemble forecast and finite-time nonlinear instability are discussed. This paper makes a necessary preparation for further theoretical and numerical investigations.

  9. Voice Disorders

    Science.gov (United States)

    Voice is the sound made by air passing from your lungs through your larynx, or voice box. In your larynx are your vocal cords, ... to make sound. For most of us, our voices play a big part in who we are, ...

  10. Every Voice

    Science.gov (United States)

    Patrick, Penny

    2008-01-01

    This article discusses how the author develops an approach that allows her students, who are part of the marginalized population, to learn the power of their own voices--not just their writing voices, but their oral voices as well. The author calls it "TWIST": Thoughts, Writing folder, Inquiring mind, Supplies, and Teamwork. It is where…

  11. Every Voice

    Science.gov (United States)

    Patrick, Penny

    2008-01-01

    This article discusses how the author develops an approach that allows her students, who are part of the marginalized population, to learn the power of their own voices--not just their writing voices, but their oral voices as well. The author calls it "TWIST": Thoughts, Writing folder, Inquiring mind, Supplies, and Teamwork. It is where…

  12. Voice restoration

    NARCIS (Netherlands)

    Hilgers, F.J.M.; Balm, A.J.M.; van den Brekel, M.W.M.; Tan, I.B.; Remacle, M.; Eckel, H.E.

    2010-01-01

    Surgical prosthetic voice restoration is the best possible option for patients to regain oral communication after total laryngectomy. It is considered to be the present "gold standard" for voice rehabilitation of laryngectomized individuals. Surgical prosthetic voice restoration, in essence, is alwa

  13. Gravity sans singularities

    CERN Document Server

    Mariwalla, K H

    2002-01-01

    Basis and limitations of singularity theorems for Gravity are examined. As singularity is a critical situation in course of time, study of time paths, in full generality of Equivalence principle, provides two mechanisms to prevent singularity. Resolution of singular Time translation generators into space of its orbits, and essential higher dimensions for Relativistic particle interactions has facets to resolve any real singularity problem. Conceptually, these varied viewpoints have a common denominator: arbitrariness in the definition of `energy' intrinsic to the space of operation in each case, so as to render absence of singularity a tautology for self-consistency of the systems.

  14. Resolution of quantum singularities

    Science.gov (United States)

    Konkowski, Deborah; Helliwell, Thomas

    2017-01-01

    A review of quantum singularities in static and conformally static spacetimes is given. A spacetime is said to be quantum mechanically non-singular if a quantum wave packet does not feel, in some sense, the presence of a singularity; mathematically, this means that the wave operator is essentially self-adjoint on the space of square integrable functions. Spacetimes with classical mild singularities (quasiregular ones) to spacetimes with classical strong curvature singularities have been tested. Here we discuss the similarities and differences between classical singularities that are healed quantum mechanically and those that are not. Possible extensions of the mathematical technique to more physically realistic spacetimes are discussed.

  15. Singular solutions of a singular differential equation

    Directory of Open Access Journals (Sweden)

    Naito Manabu

    2000-01-01

    Full Text Available An attempt is made to study the problem of existence of singular solutions to singular differential equations of the type which have never been touched in the literature. Here and are positive constants and is a positive continuous function on . A solution with initial conditions given at is called singular if it ceases to exist at some finite point . Remarkably enough, it is observed that the equation may admit, in addition to a usual blowing-up singular solution, a completely new type of singular solution with the property that Such a solution is named a black hole solution in view of its specific behavior at . It is shown in particular that there does exist a situation in which all solutions of are black hole solutions.

  16. On exceptional quotient singularities

    OpenAIRE

    Cheltsov, Ivan; Shramov, Constantin

    2011-01-01

    We study exceptional quotient singularities. In particular, we prove an exceptionality criterion in terms of the $\\alpha$-invariant of Tian, and utilize it to classify four-dimensional and five-dimensional exceptional quotient singularities.

  17. Low Vision

    Science.gov (United States)

    ... HHS USAJobs Home > Statistics and Data > Low Vision Low Vision Low Vision Defined: Low Vision is defined as the ... Ethnicity 2010 U.S. Age-Specific Prevalence Rates for Low Vision by Age, and Race/Ethnicity Table for ...

  18. Solitons on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe solitons that live on the world--volumes of D5 branes wrapped on deformed $A_2$ singularities fibered over $C(x)$. We show that monopoles are D3 branes wrapped on a node of the deformed singularity and stretched along $C(x)$. F and D--term strings are D3 branes wrapped on a node of a singularity that is deformed and resolved respectively. Domain walls require deformed $A_3$ singularities and correspond to D5 branes wrapped on a node and stretched along $C(x)$.

  19. Singular stochastic differential equations

    CERN Document Server

    Cherny, Alexander S

    2005-01-01

    The authors introduce, in this research monograph on stochastic differential equations, a class of points termed isolated singular points. Stochastic differential equations possessing such points (called singular stochastic differential equations here) arise often in theory and in applications. However, known conditions for the existence and uniqueness of a solution typically fail for such equations. The book concentrates on the study of the existence, the uniqueness, and, what is most important, on the qualitative behaviour of solutions of singular stochastic differential equations. This is done by providing a qualitative classification of isolated singular points, into 48 possible types.

  20. Singularity v1.x

    Energy Technology Data Exchange (ETDEWEB)

    2016-04-12

    Singularity is a container solution designed to facilitate mobility of compute across systems and HPC infrastructures. It does this by creating minimal containers that are defined by a specfile and files from the host system are used to build the container. The resulting container can then be launched by any Linux computer with Singularity installed regardless if the programs inside the container are present on the target system, or if they are a different version, or even incompatible versions. Singularity achieves extreme portability without sacrificing usability thus solving the need of mobility of compute. Singularity containers can be executed within a normal/standard command line process flow.

  1. Do naked singularities form?

    CERN Document Server

    Vaz, C; Vaz, Cenalo; Witten, Louis

    1995-01-01

    A naked singularity is formed by the collapse of a Sine-Gordon soliton in 1+1 dimensional dilaton gravity with a negative cosmological constant. We examine the quantum stress tensor resulting from the formation of the singularity. Consistent boundary conditions require that the incoming soliton is accompanied by a flux of incoming radiation across past null infinity, but neglecting the back reaction of the spacetime leads to the absurd conclusion that the total energy entering the system by the time the observer is able to receive information from the singularity is infinite. We conclude that the back reaction must prevent the formation of the naked singularity.

  2. On singular and sincerely singular compact patterns

    Science.gov (United States)

    Rosenau, Philip; Zilburg, Alon

    2016-08-01

    A third order dispersive equation ut +(um)x +1/b[ua∇2ub]x = 0 is used to explore two very different classes of compact patterns. In the first, the prevailing singularity at the edge induces traveling compactons, solitary waves with a compact support. In the second, the singularity induced at the perimeter of the initial excitation, entraps the dynamics within the domain's interior (nonetheless, certain very singular excitations may escape it). Here, overlapping compactons undergo interaction which may result in an interchange of their positions, or form other structures, all confined within their initial support. We conjecture, and affirm it empirically, that whenever the system admits more than one type of compactons, only the least singular compactons may be evolutionary. The entrapment due to singularities is also unfolded and confirmed numerically in a class of diffusive equations ut =uk∇2un with k > 1 and n > 0 with excitations entrapped within their initial support observed to converge toward a space-time separable structure. A similar effect is also found in a class of nonlinear Klein-Gordon Equations.

  3. Keeping Your Voice Healthy

    Science.gov (United States)

    ... Find an ENT Doctor Near You Keeping Your Voice Healthy Keeping Your Voice Healthy Patient Health Information ... heavily voice-related. Key Steps for Keeping Your Voice Healthy Drink plenty of water. Moisture is good ...

  4. Singularities around w=-1

    CERN Document Server

    Fernández-Jambrina, L

    2015-01-01

    In this talk we would like to analyse the appearance of singularities in FLRW cosmological models which evolve close to w=-1, where w is the barotropic index of the universe. We relate small terms in cosmological time around w=-1 with the correspondent scale factor of the universe and check for the formation of singularities.

  5. Domain Walls on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe domain walls that live on $A_2$ and $A_3$ singularities. The walls are BPS if the singularity is resolved and non--BPS if it is deformed and fibered. We show that these domain walls may interpolate between vacua that support monopoles and/or vortices.

  6. Introduction to singularities

    CERN Document Server

    Ishii, Shihoko

    2014-01-01

    This book is an introduction to singularities for graduate students and researchers. It is said that algebraic geometry originated in the seventeenth century with the famous work Discours de la méthode pour bien conduire sa raison, et chercher la vérité dans les sciences by Descartes. In that book he introduced coordinates to the study of geometry. After its publication, research on algebraic varieties developed steadily. Many beautiful results emerged in mathematicians’ works. Most of them were about non-singular varieties. Singularities were considered “bad” objects that interfered with knowledge of the structure of an algebraic variety. In the past three decades, however, it has become clear that singularities are necessary for us to have a good description of the framework of varieties. For example, it is impossible to formulate minimal model theory for higher-dimensional cases without singularities. Another example is that the moduli spaces of varieties have natural compactification, the boundar...

  7. Singular Continuous Spectrum for Singular Potentials

    Science.gov (United States)

    Jitomirskaya, Svetlana; Yang, Fan

    2017-05-01

    We prove that Schrödinger operators with meromorphic potentials {(H_{α,θ}u)_n=u_{n+1}+u_{n-1}+ g(θ+nα)/f(θ+nα) u_n} have purely singular continuous spectrum on the set {{E: L(E) operator. Preprint, 2015) for the almost Mathieu operator to the general family of meromorphic potentials.

  8. Singularities and Closed String Tachyons

    CERN Document Server

    Silverstein, E

    2006-01-01

    A basic problem in gravitational physics is the resolution of spacetime singularities where general relativity breaks down. The simplest such singularities are conical singularities arising from orbifold identifications of flat space, and the most challenging are spacelike singularities inside black holes (and in cosmology). Topology changing processes also require evolution through classically singular spacetimes. I briefly review how a phase of closed string tachyon condensate replaces, and helps to resolve, basic singularities of each of these types. Finally I discuss some interesting features of singularities arising in the small volume limit of compact negatively curved spaces and the emerging zoology of spacelike singularities.

  9. Surface Plasmon Singularities

    Directory of Open Access Journals (Sweden)

    Gabriel Martínez-Niconoff

    2012-01-01

    Full Text Available With the purpose to compare the physical features of the electromagnetic field, we describe the synthesis of optical singularities propagating in the free space and on a metal surface. In both cases the electromagnetic field has a slit-shaped curve as a boundary condition, and the singularities correspond to a shock wave that is a consequence of the curvature of the slit curve. As prototypes, we generate singularities that correspond to fold and cusped regions. We show that singularities in free space may generate bifurcation effects while plasmon fields do not generate these kinds of effects. Experimental results for free-space propagation are presented and for surface plasmon fields, computer simulations are shown.

  10. The Big Bang Singularity

    Science.gov (United States)

    Ling, Eric

    The big bang theory is a model of the universe which makes the striking prediction that the universe began a finite amount of time in the past at the so called "Big Bang singularity." We explore the physical and mathematical justification of this surprising result. After laying down the framework of the universe as a spacetime manifold, we combine physical observations with global symmetrical assumptions to deduce the FRW cosmological models which predict a big bang singularity. Next we prove a couple theorems due to Stephen Hawking which show that the big bang singularity exists even if one removes the global symmetrical assumptions. Lastly, we investigate the conditions one needs to impose on a spacetime if one wishes to avoid a singularity. The ideas and concepts used here to study spacetimes are similar to those used to study Riemannian manifolds, therefore we compare and contrast the two geometries throughout.

  11. Singularities in Speckled Speckle

    CERN Document Server

    Freund, Isaac

    2007-01-01

    Speckle patterns produced by random optical fields with two (or more) widely different correlation lengths exhibit speckle spots that are themselves highly speckled. Using computer simulations and analytic theory we present results for the point singularities of speckled speckle fields: optical vortices in scalar (one polarization component) fields; C points in vector (two polarization component) fields. In single correlation length fields both types of singularities tend to be more{}-or{}-less uniformly distributed. In contrast, the singularity structure of speckled speckle is anomalous: for some sets of source parameters vortices and C points tend to form widely separated giant clusters, for other parameter sets these singularities tend to form chains that surround large empty regions. The critical point statistics of speckled speckle is also anomalous. In scalar (vector) single correlation length fields phase (azimuthal) extrema are always outnumbered by vortices (C points). In contrast, in speckled speckl...

  12. Complex singularities and PDEs

    CERN Document Server

    Caflisch, R E; Sammartino, M; Sciacca, V

    2015-01-01

    In this paper we give a review on the computational methods used to characterize the complex singularities developed by some relevant PDEs. We begin by reviewing the singularity tracking method based on the analysis of the Fourier spectrum. We then introduce other methods generally used to detect the hidden singularities. In particular we show some applications of the Pad\\'e approximation, of the Kida method, and of Borel-Polya method. We apply these techniques to the study of the singularity formation of some nonlinear dispersive and dissipative one dimensional PDE of the 2D Prandtl equation, of the 2D KP equation, and to Navier-Stokes equation for high Reynolds number incompressible flows in the case of interaction with rigid boundaries.

  13. Singularity methods for magnetohydrodynamics

    Directory of Open Access Journals (Sweden)

    A. D. Alawneh

    1986-01-01

    Full Text Available Singular solutions for linearized MHD equations based on Oseen approximations have been obtained such as Oseenslet. Oseenrotlet, mass source, etc. By suitably distributing these singular solutions along the axes of symmetry of an axially symmetric bodies, we derive the approximate values for the velocity fields, the force and the momentum for the case of translational and rotational motions of such bodies in a steady flow of an incompressible viscous and magnetized fluid.

  14. Generic singularity studies revisited

    Science.gov (United States)

    Barrow, John D.; Tipler, Frank J.

    1981-04-01

    We comment on a reply by Belinskii, Khalatnikov and Lifshitz to our analysis of their conclusions regarding the general structure of space-time singularities. We support our contention that it is impossible to provide a reliable analysis of the evolution of a general (or stable) solution with local techniques in a synchronous coordinate system having a simultaneous physical singularity. Work supported in part by the National Science Foundation under grant number PHY 78-26592.

  15. Deformations of singularities

    CERN Document Server

    Stevens, Jan

    2003-01-01

    These notes deal with deformation theory of complex analytic singularities and related objects. The first part treats general theory. The central notion is that of versal deformation in several variants. The theory is developed both in an abstract way and in a concrete way suitable for computations. The second part deals with more specific problems, specially on curves and surfaces. Smoothings of singularities are the main concern. Examples are spread throughout the text.

  16. Algorithms in Singular

    Directory of Open Access Journals (Sweden)

    Hans Schonemann

    1996-12-01

    Full Text Available Some algorithms for singularity theory and algebraic geometry The use of Grobner basis computations for treating systems of polynomial equations has become an important tool in many areas. This paper introduces of the concept of standard bases (a generalization of Grobner bases and the application to some problems from algebraic geometry. The examples are presented as SINGULAR commands. A general introduction to Grobner bases can be found in the textbook [CLO], an introduction to syzygies in [E] and [St1]. SINGULAR is a computer algebra system for computing information about singularities, for use in algebraic geometry. The basic algorithms in SINGULAR are several variants of a general standard basis algorithm for general monomial orderings (see [GG]. This includes wellorderings (Buchberger algorithm ([B1], [B2] and tangent cone orderings (Mora algorithm ([M1], [MPT] as special cases: It is able to work with non-homogeneous and homogeneous input and also to compute in the localization of the polynomial ring in 0. Recent versions include algorithms to factorize polynomials and a factorizing Grobner basis algorithm. For a complete description of SINGULAR see [Si].

  17. Vision Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Vision Lab personnel perform research, development, testing and evaluation of eye protection and vision performance. The lab maintains and continues to develop...

  18. Vision Screening

    Science.gov (United States)

    ... of Prematurity Strabismus Stye (defined) Vision Screening Vision Screening Recommendations Loading... Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye ...

  19. Singular Continuous Spectrum for Singular Potentials

    Science.gov (United States)

    Jitomirskaya, Svetlana; Yang, Fan

    2017-01-01

    We prove that Schrödinger operators with meromorphic potentials {(H_{α,θ}u)_n=u_{n+1}+u_{n-1}+ g(θ+nα)/f(θ+nα) u_n} have purely singular continuous spectrum on the set {{E: L(E) Lyapunov exponent. This extends results of Jitomirskaya and Liu (Arithmetic spectral transitions for the Maryland model. CPAM, to appear) for the Maryland model and of Avila,You and Zhou (Sharp Phase transitions for the almost Mathieu operator. Preprint, 2015) for the almost Mathieu operator to the general family of meromorphic potentials.

  20. Abelian Vortices with Singularities

    CERN Document Server

    Baptista, J M

    2012-01-01

    Let L --> X be a complex line bundle over a compact connected Riemann surface. We consider the abelian vortex equations on L when the metric on the surface has finitely many point degeneracies or conical singularities and the line bundle has parabolic structure. These conditions appear naturally in the study of vortex configurations with constraints, or configurations invariant under the action of a finite group. We first show that the moduli space of singular vortex solutions is the same as in the regular case. Then we compute the total volume and total scalar curvature of the moduli space singular vortex solutions. These numbers differ from the case of regular vortices by a very natural term. Finally we exhibit explicit non-trivial vortex solutions over the thrice punctured hyperbolic sphere.

  1. Singular Mueller matrices

    CERN Document Server

    Gil, José J; José, Ignacio San

    2015-01-01

    Singular Mueller matrices play an important role in polarization algebra and have peculiar properties that stem from the fact that either the medium exhibits maximum diattenuation and/or polarizance, or because its associated canonical depolarizer has the property of fully randomizing, the circular component (at least) of the states of polarization of light incident on it. The formal reasons for which the Mueller matrix M of a given medium is singular are systematically investigated, analyzed and interpreted in the framework of the serial decompositions and the characteristic ellipsoids of M. The analysis allows for a general classification and geometric representation of singular Mueller matrices, of potential usefulness to experimentalists dealing with such media.

  2. Using modulation spectra for voice pathology detection and classification.

    Science.gov (United States)

    Markaki, Maria; Stylianou, Yannis

    2009-01-01

    In this paper, we consider the use of Modulation Spectra for voice pathology detection and classification. To reduce the high-dimensionality space generated by Modulation spectra we suggest the use of Higher Order Singular Value Decomposition (SVD) and we propose a feature selection algorithm based on the Mutual Information between subjective voice quality and computed features. Using SVM with a radial basis function (RBF) kernel as classifier, we conducted experiments on a database of sustained vowel recordings from healthy and pathological voices. For voice pathology detection, the suggested approach achieved a detection rate of 94.1% and an Area Under the Curve (AUC) score of 97.8%. For voice pathology classification, an average detection rate and AUC of 88.6% and 94.8%, respectively, was achieved in classifying polyp against keratosis leukoplakia, adductor spasmodic dysphonia and vocal nodules.

  3. Singularities of invariant connections

    Energy Technology Data Exchange (ETDEWEB)

    Amores, A.M. (Universidad Complutense, Madrid (Spain)); Gutierrez, M. (Universidad Politecnica, Madrid (Spain))

    1992-12-01

    A reductive homogeneous space M = P/G is considered, endowed with an invariant connection, i.e., such that all left translations of M induced by members of P preserve it. The authors study the set of singularities of such connections giving sufficient conditions for it to be empty, or, in other cases, familities of b-incomplete curves converging to singularities. A full description of the b-completion of a connection with M = R[sup m] (or a quotient of it) is given with information on its topology. 5 refs.

  4. Supersymmetry in singular spaces

    NARCIS (Netherlands)

    Bergshoeff, E; Kallosh, R; Van Proeyen, A

    2000-01-01

    We develop the concept of supersymmetry in singular spaces, apply it in an example for 3-branes in D = 5 and comment on 8-branes in D = 10. The new construction has an interpretation that the brane is a sink for the flux and requires adding to the standard supergravity a (D - 1)-form field and a sup

  5. Supersymmetry in singular spaces

    NARCIS (Netherlands)

    Bergshoeff, E; Kallosh, R; Van Proeyen, A

    2000-01-01

    We develop the concept of supersymmetry in singular spaces, apply it in an example for 3-branes in D = 5 and comment on 8-branes in D = 10. The new construction has an interpretation that the brane is a sink for the flux and requires adding to the standard supergravity a (D - 1)-form field and a

  6. Supersymmetry in Singular Spaces

    NARCIS (Netherlands)

    Bergshoeff, E. A.; Kallosh, R.; Proeyen, A. van

    2000-01-01

    Published in: J. High Energy Phys. 10 (2000) 033 citations recorded in [Science Citation Index] Abstract: We develop the concept of supersymmetry in singular spaces, apply it in an example for 3-branes in D=5 and comment on 8-branes in D=10. The new construction has an interpretation that the brane

  7. Pseudospherical surfaces with singularities

    DEFF Research Database (Denmark)

    Brander, David

    2016-01-01

    We study a generalization of constant Gauss curvature −1 surfaces in Euclidean 3-space, based on Lorentzian harmonic maps, that we call pseudospherical frontals. We analyse the singularities of these surfaces, dividing them into those of characteristic and non-characteristic type. We give methods...

  8. Sewn singularity cosmology

    CERN Document Server

    Szydlowski, Marek; Borowiec, Andrzej; Wojnar, Aneta

    2015-01-01

    We investigate modified gravity cosmological model $f(R)=R+\\gamma R^2$ in Palatini formalism. We consider the universe filled with the Chaplygin gas and baryonic matter. The dynamics is reduced to the 2D sewn dynamical system of a Newtonian type. For this aim we use dynamical system theory. We classify all evolutional paths in the model as well as trajectories in the phase space. We demonstrate that the presence of a degenerate freeze singularity (glued freeze type singularities) is a generic feature of early evolution of the universe. We point out that a degenerate type III of singularity can be considered as an endogenous model of inflation between the matter dominating epoch and the dark energy phase. We also investigate cosmological models with negative $\\gamma$. It is demonstrated that $\\gamma$ equal zero is a bifurcation parameter and dynamics qualitatively changes in comparison to positive $\\gamma$. Instead of the big bang the sudden singularity appears and there is a generic class of bouncing solution...

  9. Quantum effects near future singularities

    CERN Document Server

    Barrow, John D; Dito, Giuseppe; Fabris, Julio C; Houndjo, Mahouton J S

    2012-01-01

    General relativity allows a variety of future singularities to occur in the evolution of the universe. At these future singularities, the universe will end in a singular state after a finite proper time and geometrical invariants of the space time will diverge. One question that naturally arises with respect to these cosmological scenarios is the following: can quantum effects lead to the avoidance of these future singularities? We analyze this problem considering massless and conformally coupled scalar fields in an isotropic and homogeneous background leading to future singularities. It is shown that near strong, big rip-type singularities, with violation of the energy conditions, the quantum effects are very important, while near some milder classes of singularity like the sudden singularity, which preserve the energy conditions, quantum effects are irrelevant.

  10. Approximation by Multivariate Singular Integrals

    CERN Document Server

    Anastassiou, George A

    2011-01-01

    Approximation by Multivariate Singular Integrals is the first monograph to illustrate the approximation of multivariate singular integrals to the identity-unit operator. The basic approximation properties of the general multivariate singular integral operators is presented quantitatively, particularly special cases such as the multivariate Picard, Gauss-Weierstrass, Poisson-Cauchy and trigonometric singular integral operators are examined thoroughly. This book studies the rate of convergence of these operators to the unit operator as well as the related simultaneous approximation. The last cha

  11. String theory and cosmological singularities

    Indian Academy of Sciences (India)

    Sumit R Das

    2007-07-01

    In general relativity space-like or null singularities are common: they imply that `time' can have a beginning or end. Well-known examples are singularities inside black holes and initial or final singularities in expanding or contracting universes. In recent times, string theory is providing new perspectives of such singularities which may lead to an understanding of these in the standard framework of time evolution in quantum mechanics. In this article, we describe some of these approaches.

  12. Can we see naked singularities?

    OpenAIRE

    Deshingkar, Shrirang S.

    2007-01-01

    We study singularities which can form in a spherically symmetric gravitational collapse of a general matter field obeying weak energy condition. We show that no energy can reach an outside observer from a null naked singularity. That means they will not be a serious threat to the Cosmic Censorship Conjecture (CCC). For the timelike naked singularities, where only the central shell gets singular, the redshift is always finite and they can in principle, carry energy to a faraway observer. Hence...

  13. Holographic complexity and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Barbón, José L.F. [Instituto de Física Teórica IFT UAM/CSIC,C/ Nicolás Cabrera 13, Campus Universidad Autónoma de Madrid,Madrid 28049 (Spain); Rabinovici, Eliezer [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2016-01-15

    We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.

  14. Speaking and Nonspeaking Voice Professionals: Who Has the Better Voice?

    Science.gov (United States)

    Chitguppi, Chandala; Raj, Anoop; Meher, Ravi; Rathore, P K

    2017-04-18

    Voice professionals can be classified into two major subgroups: the primarily speaking and the primarily nonspeaking voice professionals. Nonspeaking voice professionals mainly include singers, whereas speaking voice professionals include the rest of the voice professionals. Although both of these groups have high vocal demands, it is currently unknown whether both groups show similar voice changes after their daily voice use. Comparison of these two subgroups of voice professionals has never been done before. This study aimed to compare the speaking voice of speaking and nonspeaking voice professionals with no obvious vocal fold pathology or voice-related complaints on the day of assessment. After obtaining relevant voice-related history, voice analysis and videostroboscopy were performed in 50 speaking and 50 nonspeaking voice professionals. Speaking voice professionals showed significantly higher incidence of voice-related complaints as compared with nonspeaking voice professionals. Voice analysis revealed that most acoustic parameters including fundamental frequency, jitter percent, and harmonic-to-noise ratio were significantly higher in speaking voice professionals, whereas videostroboscopy did not show any significant difference between the two groups. This is the first study of its kind to analyze the effect of daily voice use in the two subgroups of voice professionals with no obvious vocal fold pathology. We conclude that voice professionals should not be considered as a homogeneous group. The detrimental effects of excessive voice use were observed to occur more significantly in speaking voice professionals than in nonspeaking voice professionals. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Leveraging voice

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth

    2017-01-01

    researchers improve our practices and how could digital online video help offer more positive stories about research and higher education? How can academics in higher education be better to tell about our research, thereby reclaiming and leveraging our voice in a post-factual era? As higher education......This paper speculates on how researchers share research without diluting our credibility and how to make strategies for the future. It also calls for consideration of new traditions and practices for communicating knowledge to a wider audience across multiple media platforms. How might we...... continues to engage with digital and networked technologies it becomes increasingly relevant to question why and how academics could (re) position research knowledge in the digital and online media landscape of today and the future. The paper highlights methodological issues that arise in relation...

  16. Feeling voices.

    Directory of Open Access Journals (Sweden)

    Paolo Ammirante

    Full Text Available Two experiments investigated deaf individuals' ability to discriminate between same-sex talkers based on vibrotactile stimulation alone. Nineteen participants made same/different judgments on pairs of utterances presented to the lower back through voice coils embedded in a conforming chair. Discrimination of stimuli matched for F0, duration, and perceived magnitude was successful for pairs of spoken sentences in Experiment 1 (median percent correct = 83% and pairs of vowel utterances in Experiment 2 (median percent correct = 75%. Greater difference in spectral tilt between "different" pairs strongly predicted their discriminability in both experiments. The current findings support the hypothesis that discrimination of complex vibrotactile stimuli involves the cortical integration of spectral information filtered through frequency-tuned skin receptors.

  17. Singularities in loop quantum cosmology.

    Science.gov (United States)

    Cailleteau, Thomas; Cardoso, Antonio; Vandersloot, Kevin; Wands, David

    2008-12-19

    We show that simple scalar field models can give rise to curvature singularities in the effective Friedmann dynamics of loop quantum cosmology (LQC). We find singular solutions for spatially flat Friedmann-Robertson-Walker cosmologies with a canonical scalar field and a negative exponential potential, or with a phantom scalar field and a positive potential. While LQC avoids big bang or big rip type singularities, we find sudden singularities where the Hubble rate is bounded, but the Ricci curvature scalar diverges. We conclude that the effective equations of LQC are not in themselves sufficient to avoid the occurrence of curvature singularities.

  18. Infinitesimal Structure of Singularities

    Directory of Open Access Journals (Sweden)

    Michael Heller

    2017-02-01

    Full Text Available Some important problems of general relativity, such as the quantisation of gravity or classical singularity problems, crucially depend on geometry on very small scales. The so-called synthetic differential geometry—a categorical counterpart of the standard differential geometry—provides a tool to penetrate infinitesimally small portions of space-time. We use this tool to show that on any “infinitesimal neighbourhood” the components of the curvature tensor are themselves infinitesimal, and construct a simplified model in which the curvature singularity disappears, owing to this effect. However, one pays a price for this result. Using topoi as a generalisation of spaces requires a weakening of arithmetic (the existence of infinitesimals and of logic (to the intuitionistic logic. Is this too high a price to pay for acquiring a new method of solving unsolved problems in physics? Without trying, we shall never know the answer.

  19. Multiscale singularity trees

    DEFF Research Database (Denmark)

    Somchaipeng, Kerawit; Sporring, Jon; Johansen, Peter

    2007-01-01

    We propose MultiScale Singularity Trees (MSSTs) as a structure to represent images, and we propose an algorithm for image comparison based on comparing MSSTs. The algorithm is tested on 3 public image databases and compared to 2 state-of-theart methods. We conclude that the computational complexity...... of our algorithm only allows for the comparison of small trees, and that the results of our method are comparable with state-of-the-art using much fewer parameters for image representation....

  20. Neural Excitability and Singular Bifurcations.

    Science.gov (United States)

    De Maesschalck, Peter; Wechselberger, Martin

    2015-12-01

    We discuss the notion of excitability in 2D slow/fast neural models from a geometric singular perturbation theory point of view. We focus on the inherent singular nature of slow/fast neural models and define excitability via singular bifurcations. In particular, we show that type I excitability is associated with a novel singular Bogdanov-Takens/SNIC bifurcation while type II excitability is associated with a singular Andronov-Hopf bifurcation. In both cases, canards play an important role in the understanding of the unfolding of these singular bifurcation structures. We also explain the transition between the two excitability types and highlight all bifurcations involved, thus providing a complete analysis of excitability based on geometric singular perturbation theory.

  1. Computational vision

    CERN Document Server

    Wechsler, Harry

    1990-01-01

    The book is suitable for advanced courses in computer vision and image processing. In addition to providing an overall view of computational vision, it contains extensive material on topics that are not usually covered in computer vision texts (including parallel distributed processing and neural networks) and considers many real applications.

  2. Quantum Singularity of Quasiregular Spacetimes

    Science.gov (United States)

    Konkowski, Deborah A.; Helliwell, Thomas M.

    2001-04-01

    A quasiregular spacetime is a spacetime with a classical quasiregular singularity, the mildest form of true singularity [G.F.R. Ellis and B.G. Schmidt, Gen. Rel. Grav. 8, 915 (1977)]. The definition of G.T. Horowitz and D. Marolf [Phys. Rev. D52, 5670 (1995)] for a quantum-mechanically singular spacetime is one in which the spatial-derivative operator in the Klein-Gordon equation for a massive scalar field is not essentially self-adjoint. In such a quantum-mechanically singular spacetime, the time evolution of a quantum test particle is not uniquely determined. Horowitz and Marolf showed that a two-dimensional spacetime with a classical conical singularity (i.e., a two-dimensional quasiregular singularity) is also quantum-mechanically singular. Here we show that a class of static quasiregular spacetimes possessing disclinations and dislocations [R.A.Puntigam and H.H. Soleng , Class. Quantum Grav. 14, 1129 (1997)] is quantum-mechanically singular, since the scalar wave operator is not essentially self-adjoint. These spacetimes include an idealized cosmic string spacetime, i.e., a four-dimensional spacetime with conical singularity, and a Galtsov/Letelier/Tod spacetime featuring a screw dislocation [K.P. Tod, Class. Quantum Grav. 11, 1331 (1994); D.V. Galtsov and P.S. Letelier, Phys. Rev. D47, 4273 (1993)]. In addition, we show that the definition of quantum-mechanically singular spacetimes can be extended to include Maxwell and Dirac fields.

  3. Dimensionality in voice quality.

    Science.gov (United States)

    Bele, Irene Velsvik

    2007-05-01

    This study concerns speaking voice quality in a group of male teachers (n = 35) and male actors (n = 36), as the purpose was to investigate normal and supranormal voices. The goal was the development of a method of valid perceptual evaluation for normal to supranormal and resonant voices. The voices (text reading at two loudness levels) had been evaluated by 10 listeners, for 15 vocal characteristics using VA scales. In this investigation, the results of an exploratory factor analysis of the vocal characteristics used in this method are presented, reflecting four dimensions of major importance for normal and supranormal voices. Special emphasis is placed on the effects on voice quality of a change in the loudness variable, as two loudness levels are studied. Furthermore, the vocal characteristics Sonority and Ringing voice quality are paid special attention, as the essence of the term "resonant voice" was a basic issue throughout a doctoral dissertation where this study was included.

  4. Voice box (image)

    Science.gov (United States)

    The larynx, or voice box, is located in the neck and performs several important functions in the body. The larynx is involved in swallowing, breathing, and voice production. Sound is produced when the air which ...

  5. Voice and Aging

    Science.gov (United States)

    ... dramatic voice changes are those during childhood and adolescence. The larynx (or voice box) and vocal cord tissues do not fully mature until late teenage years. Hormone-related changes during adolescence are ...

  6. Voice and endocrinology

    OpenAIRE

    KVS Hari Kumar; Anurag Garg; Ajai Chandra, N. S.; Singh, S. P.; Rakesh Datta

    2016-01-01

    Voice is one of the advanced features of natural evolution that differentiates human beings from other primates. The human voice is capable of conveying the thoughts into spoken words along with a subtle emotion to the tone. This extraordinary character of the voice in expressing multiple emotions is the gift of God to the human beings and helps in effective interpersonal communication. Voice generation involves close interaction between cerebral signals and the peripheral apparatus consistin...

  7. DLMS Voice Data Entry.

    Science.gov (United States)

    1980-06-01

    between operator and computer displayed on ADM-3A 20c A-I Possible Hardware Configuration for a Multistation Cartographic VDES ...this program a Voice Recognition System (VRS) which can be used to explore the use of voice data entry ( VDE ) in the DIMS or other cartographic data...Multi-Station Cartographic Voice Data Entry System An engineering development model voice data entry system ( VDES ) could be most efficiently

  8. Dilatonic effects near naked singularities

    CERN Document Server

    Morris, J R

    2011-01-01

    Static spherically symmetric solutions of 4d Brans-Dicke theory include a set of naked singularity solutions. Dilatonic effects near the naked singularities result in either a shielding or an antishielding effect from intruding massive test particles. One result is that for a portion of the solution parameter space, no communication between the singularity and a distant observer is possible via massive particle exchanges. Kaluza-Klein gravity is considered as a special case.

  9. How Does Naked Singularity Look?

    OpenAIRE

    Nakao, Ken-ichi; Kobayashi, Naoki; Ishihara, Hideki

    2002-01-01

    There are non-radial null geodesics emanating from the shell focusing singularity formed at the symmetric center in a spherically symmetric dust collapse. In this article, assuming the self-similarity in the region filled with the dust fluid, we study these singular null geodesics in detail. We see the time evolution of the angular diameter of the central naked singularity and show that it might be bounded above by the value corresponding to the circular null geodesic in the Schwarzschild spa...

  10. Writing with Voice

    Science.gov (United States)

    Kesler, Ted

    2012-01-01

    In this Teaching Tips article, the author argues for a dialogic conception of voice, based in the work of Mikhail Bakhtin. He demonstrates a dialogic view of voice in action, using two writing examples about the same topic from his daughter, a fifth-grade student. He then provides five practical tips for teaching a dialogic conception of voice in…

  11. Tips for Healthy Voices

    Science.gov (United States)

    ... social interaction as well as for most people’s occupation. Proper care and use of your voice will give you the best chance for having a healthy voice for your entire lifetime. Hoarseness or roughness in your voice is often ...

  12. Living with vision loss

    Science.gov (United States)

    Diabetes - vision loss; Retinopathy - vision loss; Low vision; Blindness - vision loss ... Low vision is a visual disability. Wearing regular glasses or contacts does not help. People with low vision have ...

  13. Voice handicap in singers.

    Science.gov (United States)

    Murry, Thomas; Zschommler, Anne; Prokop, Jan

    2009-05-01

    The study aimed to determine the differences in responses to the Voice Handicap Index (VHI-10) between singers and nonsingers and to evaluate the ranked order differences of the VHI-10 statements for both groups. The VHI-10 was modified to include statements related to the singing voice for comparison to the original VHI-10. Thirty-five nonsingers with documented voice disorders responded to the VHI-10. A second group, consisting of 35 singers with voice complaints, responded to the VHI-10 with three statements added specifically addressing the singing voice. Data from both groups were analyzed in terms of overall subject self-rating of voice handicap and the rank order of statements from least to most important. The difference between the mean VHI-10 for the singers and nonsingers was not statistically significant, thus, supporting the validity of the VHI-10. However, the 10 statements were ranked differently in terms of their importance by both groups. In addition, when three statements related specifically to the singing voice were substituted in the original VHI-10, the singers judged their voice problem to be more severe than when using the original VHI-10. The type of statements used to assess self-perception of voice handicap may be related to the subject population. Singers with voice problems do not rate their voices to be more handicapped than nonsingers unless statements related specifically to singing are included.

  14. Singular coverings of toposes

    CERN Document Server

    Bunge, Marta

    2006-01-01

    The self-contained theory of certain singular coverings of toposes called complete spreads, that is presented in this volume, is a field of interest to topologists working in knot theory, as well as to various categorists. It extends the complete spreads in topology due to R. H. Fox (1957) but, unlike the classical theory, it emphasizes an unexpected connection with topos distributions in the sense of F. W. Lawvere (1983). The constructions, though often motivated by classical theories, are sometimes quite different from them. Special classes of distributions and of complete spreads, inspired respectively by functional analysis and topology, are studied. Among the former are the probability distributions; the branched coverings are singled out amongst the latter. This volume may also be used as a textbook for an advanced one-year graduate course introducing topos theory with an emphasis on geometric applications. Throughout the authors emphasize open problems. Several routine proofs are left as exercises, but...

  15. A SINGULARLY UNFEMININE PROFESSION

    CERN Document Server

    2016-01-01

    Mary K Gaillard back to CERN to present her book and talk diversity - In 1981 Mary K Gaillard became the first woman on the physics faculty at the University of California at Berkeley. Her career as a theoretical physicist spanned the period from the inception — in the late 1960s and early 1970s — of what is now known as the Standard Model of particle physics and its experimental confirmation, culminating with the discovery of the Higgs particle in 2012. Her book A Singularly Unfeminine Profession recounts Gaillard's experiences as a woman in a very male-dominated field, while tracing the development of the Standard Model as she witnessed it and participated in it.

  16. Micro Vision

    OpenAIRE

    Ohba, Kohtaro; OHARA, Kenichi

    2007-01-01

    In the field of the micro vision, there are few researches compared with macro environment. However, applying to the study result for macro computer vision technique, you can measure and observe the micro environment. Moreover, based on the effects of micro environment, it is possible to discovery the new theories and new techniques.

  17. Entanglement Entropy for Singular Surfaces

    CERN Document Server

    Myers, Robert C

    2012-01-01

    We study entanglement entropy for regions with a singular boundary in higher dimensions using the AdS/CFT correspondence and find that various singularities make new universal contributions. When the boundary CFT has an even spacetime dimension, we find that the entanglement entropy of a conical surface contains a term quadratic in the logarithm of the UV cut-off. In four dimensions, the coefficient of this contribution is proportional to the central charge 'c'. A conical singularity in an odd number of spacetime dimensions contributes a term proportional to the logarithm of the UV cut-off. We also study the entanglement entropy for various boundary surfaces with extended singularities. In these cases, similar universal terms may appear depending on the dimension and curvature of the singular locus.

  18. Naked singularities are not singular in distorted gravity

    Energy Technology Data Exchange (ETDEWEB)

    Garattini, Remo, E-mail: Remo.Garattini@unibg.it [Università degli Studi di Bergamo, Facoltà di Ingegneria, Viale Marconi 5, 24044 Dalmine (Bergamo) (Italy); I.N.F.N. – sezione di Milano, Milan (Italy); Majumder, Barun, E-mail: barunbasanta@iitgn.ac.in [Indian Institute of Technology Gandhinagar, Ahmedabad, Gujarat 382424 (India)

    2014-07-15

    We compute the Zero Point Energy (ZPE) induced by a naked singularity with the help of a reformulation of the Wheeler–DeWitt equation. A variational approach is used for the calculation with Gaussian Trial Wave Functionals. The one loop contribution of the graviton to the ZPE is extracted keeping under control the UltraViolet divergences by means of a distorted gravitational field. Two examples of distortion are taken under consideration: Gravity's Rainbow and Noncommutative Geometry. Surprisingly, we find that the ZPE is no more singular when we approach the singularity.

  19. Singing voice outcomes following singing voice therapy.

    Science.gov (United States)

    Dastolfo-Hromack, Christina; Thomas, Tracey L; Rosen, Clark A; Gartner-Schmidt, Jackie

    2016-11-01

    The objectives of this study were to describe singing voice therapy (SVT), describe referred patient characteristics, and document the outcomes of SVT. Retrospective. Records of patients receiving SVT between June 2008 and June 2013 were reviewed (n = 51). All diagnoses were included. Demographic information, number of SVT sessions, and symptom severity were retrieved from the medical record. Symptom severity was measured via the 10-item Singing Voice Handicap Index (SVHI-10). Treatment outcome was analyzed by diagnosis, history of previous training, and SVHI-10. SVHI-10 scores decreased following SVT (mean change = 11, 40% decrease) (P singing lessons (n = 10) also completed an average of three SVT sessions. Primary muscle tension dysphonia (MTD1) and benign vocal fold lesion (lesion) were the most common diagnoses. Most patients (60%) had previous vocal training. SVHI-10 decrease was not significantly different between MTD and lesion. This is the first outcome-based study of SVT in a disordered population. Diagnosis of MTD or lesion did not influence treatment outcomes. Duration of SVT was short (approximately three sessions). Voice care providers are encouraged to partner with a singing voice therapist to provide optimal care for the singing voice. This study supports the use of SVT as a tool for the treatment of singing voice disorders. 4 Laryngoscope, 126:2546-2551, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  20. Computer vision

    Science.gov (United States)

    Gennery, D.; Cunningham, R.; Saund, E.; High, J.; Ruoff, C.

    1981-01-01

    The field of computer vision is surveyed and assessed, key research issues are identified, and possibilities for a future vision system are discussed. The problems of descriptions of two and three dimensional worlds are discussed. The representation of such features as texture, edges, curves, and corners are detailed. Recognition methods are described in which cross correlation coefficients are maximized or numerical values for a set of features are measured. Object tracking is discussed in terms of the robust matching algorithms that must be devised. Stereo vision, camera control and calibration, and the hardware and systems architecture are discussed.

  1. The theory of singular perturbations

    CERN Document Server

    De Jager, E M

    1996-01-01

    The subject of this textbook is the mathematical theory of singular perturbations, which despite its respectable history is still in a state of vigorous development. Singular perturbations of cumulative and of boundary layer type are presented. Attention has been given to composite expansions of solutions of initial and boundary value problems for ordinary and partial differential equations, linear as well as quasilinear; also turning points are discussed. The main emphasis lies on several methods of approximation for solutions of singularly perturbed differential equations and on the mathemat

  2. BOUNDEDNESS OF MAXIMAL SINGULAR INTEGRALS

    Institute of Scientific and Technical Information of China (English)

    CHEN JIECHENG; ZHU XIANGRONG

    2005-01-01

    The authors study the singular integrals under the Hormander condition and the measure not satisfying the doubling condition. At first, if the corresponding singular integral is bounded from L2 to itseff, it is proved that the maximal singu lar integral is bounded from L∞ to RBMO except that it is infinite μ-a.e. on Rd. A sufficient condition and a necessary condition such that the maximal singular integral is bounded from L2 to itself are also obtained. There is a small gap between the two conditions.

  3. Contrast structure for singular singularly perturbed boundary value problem

    Institute of Scientific and Technical Information of China (English)

    王爱峰; 倪明康

    2014-01-01

    The step-type contrast structure for a singular singularly perturbed problem is shown. By use of the method of boundary function, the formal asymptotic expansion is constructed. At the same time, based on sewing orbit smooth, the existence of the step-type solution and the uniform validity of the asymptotic expansion are proved. Finally, an example is given to demonstrate the effectiveness of the present results.

  4. What Is Low Vision?

    Science.gov (United States)

    ... Condition Eye Health Low Vision What Is Low Vision? What "Low Vision" Means Signs and Symptoms of ... Services The Low Vision Pilot Project What "Low Vision" Means As we age, our eyes change too. ...

  5. All Vision Impairment

    Science.gov (United States)

    ... Home > Statistics and Data > All Vision Impairment All Vision Impairment Vision Impairment Defined Vision impairment is defined as the ... Ethnicity 2010 U.S. Age-Specific Prevalence Rates for Vision Impairment by Age and Race/Ethnicity Table for ...

  6. Healthy Living, Healthy Vision

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  7. Pregnancy and Your Vision

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  8. Clinical Voices - an update

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Weed, Ethan

    Anomalous aspects of speech and voice, including pitch, fluency, and voice quality, are reported to characterise many mental disorders. However, it has proven difficult to quantify and explain this oddness of speech by employing traditional statistical methods. In this talk we will show how the t...... the temporal dynamics of the voice in Asperger's patients enable us to automatically reconstruct the diagnosis, and assess the Autism quotient score. We then generalise the findings to Danish and American children with autism....

  9. Effects of Medications on Voice

    Science.gov (United States)

    ... ENT Doctor Near You Effects of Medications on Voice Effects of Medications on Voice Patient Health Information ... entnet.org . Could Your Medication Be Affecting Your Voice? Some medications including prescription, over-the-counter, and ...

  10. Gravitational collapse and naked singularities

    Indian Academy of Sciences (India)

    Tomohiro Harada

    2004-10-01

    Gravitational collapse is one of the most striking phenomena in gravitational physics. The cosmic censorship conjecture has provided strong motivation for research in this field. In the absence of a general proof for censorship, many examples have been proposed, in which naked singularity is the outcome of gravitational collapse. Recent developments have revealed that there are examples of naked singularity formation in the collapse of physically reasonable matter fields, although the stability of these examples is still uncertain. We propose the concept of `effective naked singularities', which will be quite helpful because general relativity has limitation in its application at the high-energy end. The appearance of naked singularities is not detestable but can open a window for the new physics of strongly curved space-times.

  11. Holographic signatures of cosmological singularities.

    Science.gov (United States)

    Engelhardt, Netta; Hertog, Thomas; Horowitz, Gary T

    2014-09-19

    To gain insight into the quantum nature of cosmological singularities, we study anisotropic Kasner solutions in gauge-gravity duality. The dual description of the bulk evolution towards the singularity involves N=4 super Yang-Mills theory on the expanding branch of deformed de Sitter space and is well defined. We compute two-point correlators of Yang-Mills operators of large dimensions using spacelike geodesics anchored on the boundary. The correlators show a strong signature of the singularity around horizon scales and decay at large boundary separation at different rates in different directions. More generally, the boundary evolution exhibits a process of particle creation similar to that in inflation. This leads us to conjecture that information on the quantum nature of cosmological singularities is encoded in long-wavelength features of the boundary wave function.

  12. Penrose Limits and Spacetime Singularities

    CERN Document Server

    Blau, Matthias; O'Loughlin, M; Papadopoulos, G; Blau, Matthias; Borunda, Monica; Loughlin, Martin O'; Papadopoulos, George

    2003-01-01

    We give a covariant characterisation of the Penrose plane wave limit: the plane wave profile matrix $A(u)$ is the restriction of the null geodesic deviation matrix (curvature tensor) of the original spacetime metric to the null geodesic, evaluated in a comoving frame. We also consider the Penrose limits of spacetime singularities and show that for a large class of black hole, cosmological and null singularities (of Szekeres-Iyers ``power-law type''), including those of the FRW and Schwarzschild metrics, the result is a singular homogeneous plane wave with profile $A(u)\\sim u^{-2}$, the scale invariance of the latter reflecting the power-law behaviour of the singularities.

  13. Dual geometries and spacetime singularities

    CERN Document Server

    Quirós, I

    2000-01-01

    The concept of geometrical duality is disscused in the context of Brans-Dicke theory and extended to general relativity. It is shown, in some generic cases, that spacetime singularities that arise in usual Riemannian general relativity, may be avoided in its dual representation: Weyl-like general relativity, thus providing a singularity-free picture of the World that is physicaly equivalent to the canonical general relativistic one.

  14. Polarization singularity anisotropy: determining monstardom

    CERN Document Server

    Dennis, Mark R

    2008-01-01

    C points, that is isolated points of circular polarization in transverse fields of varying polarization, are classified morphologically into three distinct types, known as lemons, stars and monstars. These morphologies are interpreted here according to two natural parameters associated with the singularity, namely the anisotropy of the C point, and the polarization azimuth on the anisotropy axis. In addition to providing insight into singularity morphology, this observation applies to the densities of the various morphologies in isotropic random polarization speckle fields.

  15. Singular traces theory and applications

    CERN Document Server

    Sukochev, Fedor; Zanin, Dmitriy

    2012-01-01

    This text is the first complete study and monograph dedicated to singular traces. For mathematical readers the text offers, due to Nigel Kalton's contribution, a complete theory of traces on symmetrically normed ideals of compact operators. For mathematical physicists and other users of Connes' noncommutative geometry the text offers a complete reference to Dixmier traces and the deeper mathematical features of singular traces. An application section explores the consequences of these features, which previously were not discussed in general texts on noncommutative geometry.

  16. Dynkin graphs and quadrilateral singularities

    CERN Document Server

    Urabe, Tohsuke

    1993-01-01

    The study of hypersurface quadrilateral singularities can be reduced to the study of elliptic K3 surfaces with a singular fiber of type I * 0 (superscript *, subscript 0), and therefore these notes consider, besides the topics of the title, such K3 surfaces too. The combinations of rational double points that can occur on fibers in the semi-universal deformations of quadrilateral singularities are examined, to show that the possible combinations can be described by a certain law from the viewpoint of Dynkin graphs. This is equivalent to saying that the possible combinations of singular fibers in elliptic K3 surfaces with a singular fiber of type I * 0 (superscript *, subscript 0) can be described by a certain law using classical Dynkin graphs appearing in the theory of semi-simple Lie groups. Further, a similar description for thecombination of singularities on plane sextic curves is given. Standard knowledge of algebraic geometry at the level of graduate students is expected. A new method based on graphs wil...

  17. SINGULAR INTEGRALS ALONG SURFACES ON PRODUCT DOMAINS

    Institute of Scientific and Technical Information of China (English)

    Hussain Al-Qassem

    2004-01-01

    In this paper, we study the mapping properties of singular integral operator along surfaces of revolution. We prove Lp bounds (1 < p <∞) for such singular integral operators as well as for their corresponding maximal truncated singular integrals if the singular kernels are allowed to be in certain block spaces.

  18. A New Type of Singularity Theorem

    CERN Document Server

    Senovilla, José M M

    2007-01-01

    A new type of singularity theorem, based on spatial averages of physical quantities, is presented and discussed. Alternatively, the results inform us of when a spacetime can be singularity-free. This theorem provides a decisive observational difference between singular and non-singular, globally hyperbolic, open cosmological models.

  19. Voiced Reading and Rhythm

    Institute of Scientific and Technical Information of China (English)

    詹艳萍

    2007-01-01

    Since voiced reading is an important way in learning English,rhythm is the most critical factor that enables to read beautifully.This article illustrates the relationship between rhythm and voiced reading,the importance of rhythm,and the methods to develop the sense of rhythm.

  20. Clinical Voices - an update

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Weed, Ethan

    Anomalous aspects of speech and voice, including pitch, fluency, and voice quality, are reported to characterise many mental disorders. However, it has proven difficult to quantify and explain this oddness of speech by employing traditional statistical methods. In this talk we will show how...

  1. Borderline Space for Voice

    Science.gov (United States)

    Batchelor, Denise

    2012-01-01

    Being on the borderline as a student in higher education is not always negative, to do with marginalisation, exclusion and having a voice that is vulnerable. Paradoxically, being on the edge also has positive connections with integration, inclusion and having a voice that is strong. Alternative understandings of the concept of borderline space can…

  2. Voice and endocrinology

    Directory of Open Access Journals (Sweden)

    KVS Hari Kumar

    2016-01-01

    Full Text Available Voice is one of the advanced features of natural evolution that differentiates human beings from other primates. The human voice is capable of conveying the thoughts into spoken words along with a subtle emotion to the tone. This extraordinary character of the voice in expressing multiple emotions is the gift of God to the human beings and helps in effective interpersonal communication. Voice generation involves close interaction between cerebral signals and the peripheral apparatus consisting of the larynx, vocal cords, and trachea. The human voice is susceptible to the hormonal changes throughout life right from the puberty until senescence. Thyroid, gonadal and growth hormones have tremendous impact on the structure and function of the vocal apparatus. The alteration of voice is observed even in physiological states such as puberty and menstruation. Astute clinical observers make out the changes in the voice and refer the patients for endocrine evaluation. In this review, we shall discuss the hormonal influence on the voice apparatus in normal and endocrine disorders.

  3. Face the voice

    DEFF Research Database (Denmark)

    Lønstrup, Ansa

    2014-01-01

    will be based on a reception aesthetic and phenomenological approach, the latter as presented by Don Ihde in his book Listening and Voice. Phenomenologies of Sound , and my analytical sketches will be related to theoretical statements concerning the understanding of voice and media (Cavarero, Dolar, La...

  4. Voice integrated systems

    Science.gov (United States)

    Curran, P. Mike

    1977-01-01

    The program at Naval Air Development Center was initiated to determine the desirability of interactive voice systems for use in airborne weapon systems crew stations. A voice recognition and synthesis system (VRAS) was developed and incorporated into a human centrifuge. The speech recognition aspect of VRAS was developed using a voice command system (VCS) developed by Scope Electronics. The speech synthesis capability was supplied by a Votrax, VS-5, speech synthesis unit built by Vocal Interface. The effects of simulated flight on automatic speech recognition were determined by repeated trials in the VRAS-equipped centrifuge. The relationship of vibration, G, O2 mask, mission duration, and cockpit temperature and voice quality was determined. The results showed that: (1) voice quality degrades after 0.5 hours with an O2 mask; (2) voice quality degrades under high vibration; and (3) voice quality degrades under high levels of G. The voice quality studies are summarized. These results were obtained with a baseline of 80 percent recognition accuracy with VCS.

  5. Ontario's Student Voice Initiative

    Science.gov (United States)

    Courtney, Jean

    2014-01-01

    This article describes in some detail aspects of the Student Voice initiative funded and championed by Ontario's Ministry of Education since 2008. The project enables thousands of students to make their voices heard in meaningful ways and to participate in student-led research. Some students from grades 7 to 12 become members of the Student…

  6. Negative Point Mass Singularities in General Relativity

    CERN Document Server

    Robbins, Nicholas

    2010-01-01

    First we review the definition of a negative point mass singularity. Then we examine the gravitational lensing effects of these singularities in isolation and with shear and convergence from continuous matter. We review the Inverse Mean Curvature Flow and use this flow to prove some new results about the mass of a singularity, the ADM mass of the manifold, and the capacity of the singularity. We describe some particular examples of these singularities that exhibit additional symmetries.

  7. On the Milnor fibers of sandwiched singularities

    OpenAIRE

    Nemethi, Andras; Popescu-Pampu, Patrick

    2009-01-01

    The sandwiched surface singularities are those rational surface singularities which dominate birationally smooth surface singularities. de Jong and van Straten showed that one can reduce the study of the deformations of a sandwiched surface singularity to the study of deformations of a 1-dimensional object, a so-called decorated plane curve singularity. In particular, the Milnor fibers corresponding to their various smoothing components may be reconstructed up to diffeomorphisms from those de...

  8. On the genericity of spacetime singularities

    Indian Academy of Sciences (India)

    Pankaj S Joshi

    2007-07-01

    We consider here the genericity aspects of spacetime singularities that occur in cosmology and in gravitational collapse. The singularity theorems (that predict the occurrence of singularities in general relativity) allow the singularities of gravitational collapse to be either visible to external observers or covered by an event horizon of gravity. It is shown that the visible singularities that develop as final states of spherical collapse are generic. Some consequences of this fact are discussed.

  9. EasyVoice: Integrating voice synthesis with Skype

    CERN Document Server

    Condado, Paulo A

    2007-01-01

    This paper presents EasyVoice, a system that integrates voice synthesis with Skype. EasyVoice allows a person with voice disabilities to talk with another person located anywhere in the world, removing an important obstacle that affect these people during a phone or VoIP-based conversation.

  10. Spacetime Singularities in Quantum Gravity

    Science.gov (United States)

    Minassian, Eric A.

    2000-04-01

    Recent advances in 2+1 dimensional quantum gravity have provided tools to study the effects of quantization of spacetime on black hole and big bang/big crunch type singularities. I investigate effects of quantization of spacetime on singularities of the 2+1 dimensional BTZ black hole and the 2+1 dimensional torus universe. Hosoya has considered the BTZ black hole, and using a "quantum generalized affine parameter" (QGAP), has shown that, for some specific paths, quantum effects "smear" the singularities. Using gaussian wave functions as generic wave functions, I found that, for both BTZ black hole and the torus universe, there are families of paths that still reach the singularities with a finite QGAP, suggesting that singularities persist in quantum gravity. More realistic calculations, using modular invariant wave functions of Carlip and Nelson for the torus universe, offer further support for this conclusion. Currently work is in progress to study more realistic quantum gravity effects for BTZ black holes and other spacetime models.

  11. Singular solutions of doubly singular parabolic equations with absorption

    Directory of Open Access Journals (Sweden)

    Yuanwei Qi

    2000-11-01

    Full Text Available In this paper we study a doubly singular parabolic equation with absorption, $$ u_t = hbox{ m div} ( |abla u^m|^{p-2}abla u^m -u^q $$ with $m>0$, $p>1$, $m(p-11$. We give a complete classification of solutions, which we call singular, that are non-negative, non-trivial, continuous in ${mathbb R}^n imes [0, inftybackslash{(0,0} $, and satisfy $u(x,0=0$ for all $xeq 0$. Applications of similar but simpler equations show that these solutions are very important in the study of intermediate asymptotic behavior of general solutions.

  12. On the singularities of solutions to singular perturbation problems

    Energy Technology Data Exchange (ETDEWEB)

    Fruchard, A [Laboratoire de Mathematiques, Informatique et Applications, Faculte des Sciences et Techniques, Universite de Haute Alsace, 4 rue des Freres Lumiere, 68093 Mulhouse cedex (France); Schaefke, R [Departement de Mathematiques, Universite Louis Pasteur, 7 rue Rene-Descartes, 67084 Strasbourg cedex (France)

    2005-01-01

    We consider a singularly perturbed complex first order ODE {epsilon}u ' {phi}(x, u, a, {epsilon}), x, u element of C, {epsilon} > 0 is a small complex parameter and a element of C is a control parameter. It is proven that the singularities of some solutions are regularly spaced and that they move from one to the next as a runs about a loop of index one around a value of overstability. This gives a positive answer to a question of J. L. Callot.

  13. Voice Savers for Music Teachers

    Science.gov (United States)

    Cookman, Starr

    2012-01-01

    Music teachers are in a class all their own when it comes to voice use. These elite vocal athletes require stamina, strength, and flexibility from their voices day in, day out for hours at a time. Voice rehabilitation clinics and research show that music education ranks high among the professionals most commonly affected by voice problems.…

  14. Neural mechanisms for voice recognition

    NARCIS (Netherlands)

    Andics, A.V.; McQueen, J.M.; Petersson, K.M.; Gal, V.; Rudas, G.; Vidnyanszky, Z.

    2010-01-01

    We investigated neural mechanisms that support voice recognition in a training paradigm with fMRI. The same listeners were trained on different weeks to categorize the mid-regions of voice-morph continua as an individual's voice. Stimuli implicitly defined a voice-acoustics space, and training expli

  15. Brane-like singularities with no brane

    Energy Technology Data Exchange (ETDEWEB)

    Yurov, A.V., E-mail: artyom_yurov@mail.r [I. Kant Russian State University, Theoretical Physics Department, Al. Nevsky St. 14, Kaliningrad 236041 (Russian Federation)

    2010-05-17

    We use a method of linearization to study the emergence of the future cosmological singularity characterized by finite value of the cosmological radius. We uncover such singularities that keep Hubble parameter finite while making all higher derivatives of the scale factor (starting out from the a) diverge as the cosmological singularity is approached. Since such singularities has been obtained before in the brane world model we name them the 'brane-like' singularities. These singularities can occur during the expanding phase in usual Friedmann universe filled with both a self-acting, minimally coupled scalar field and a homogeneous tachyon field. We discover a new type of finite-time, future singularity which is different from type I-IV cosmological singularities in that it has the scale factor, pressure and density finite and nonzero. The generalization of w-singularity is obtained as well.

  16. Self-similar singular solution of doubly singular parabolic equation with gradient absorption term

    Directory of Open Access Journals (Sweden)

    Shi Peihu

    2006-01-01

    Full Text Available We deal with the self-similar singular solution of doubly singular parabolic equation with a gradient absorption term for , and in . By shooting and phase plane methods, we prove that when there exists self-similar singular solution, while there is no any self-similar singular solution. In case of existence, the self-similar singular solution is the self-similar very singular solutions which have compact support. Moreover, the interface relation is obtained.

  17. Naked singularities as particle accelerators

    CERN Document Server

    Patil, Mandar; 10.1103/PhysRevD.82.104049

    2010-01-01

    We investigate here the particle acceleration by naked singularities to arbitrarily high center of mass energies. Recently it has been suggested that black holes could be used as particle accelerators to probe the Planck scale physics. We show that the naked singularities serve the same purpose and probably would do better than their black hole counterparts. We focus on the scenario of a self-similar gravitational collapse starting from a regular initial data, leading to the formation of a globally naked singularity. It is seen that when particles moving along timelike geodesics interact and collide near the Cauchy horizon, the energy of collision in the center of mass frame will be arbitrarily high, thus offering a window to Planck scale physics.

  18. El singular como diferencia divina

    Directory of Open Access Journals (Sweden)

    Maria Jose Binetti

    2012-01-01

    Full Text Available Mucho se ha hablado sobre la posición de la diferencia como motor dialéctico de la existencia singular kierkegaardiana. El pecado, el otro o el Otro fisuran la subjetividad humana y la obligan a una identidad que guardará siempre la herida. El sujeto de la escisión es, en este sentido, el existente mismo, y tal debe ser el caso si la perspectiva se concentra en la individualidad. No obstante, y desde el punto de vista especulativo, creemos que los mismos principios utilizados por Kierkegaard para explicar el dinamismo de la existencia singular nos llevan más lejos, a saber, nos conducen al absoluto mismo como sujeto último de toda alteridad, respecto del cual el singular hace la diferencia.

  19. Infrared singularities in QCD amplitudes

    CERN Document Server

    Gardi, Einan

    2009-01-01

    We review recent progress in determining the infrared singularity structure of on-shell scattering amplitudes in massless gauge theories. We present a simple ansatz where soft singularities of any scattering amplitude of massless partons, to any loop order, are written as a sum over colour dipoles, governed by the cusp anomalous dimension. We explain how this formula was obtained, as the simplest solution to a newly-derived set of equations constraining the singularity structure to all orders. We emphasize the physical ideas underlying this derivation: the factorization of soft and collinear modes, the special properties of soft gluon interactions, and the notion of the cusp anomaly. Finally, we briefly discuss potential multi-loop contributions going beyond the sum-over-dipoles formula, which cannot be excluded at present.

  20. Singular Integrals with Bilinear Phases

    Institute of Scientific and Technical Information of China (English)

    Elena PRESTINI

    2006-01-01

    We prove the boundedness from Lp(T2) to itself, 1 < p <∞, of highly oscillatory singular integrals Sf(x, y) presenting singularities of the kind of the double Hilbert transform on a non-rectangular domain of integration, roughly speaking, defined by |y′| > | x′|, and presenting phases λ(Ax + By) with 0 ≤ A, B ≤ 1 and λ≥ 0. The norms of these oscillatory singular integrals are proved to be independent of all parameters A, B and λ involved. Our method extends to a more general family of phases. These results are relevant to problems of almost everywhere convergence of double Fourier and Walsh series.

  1. Dominant Voice in Hamlet

    Institute of Scientific and Technical Information of China (English)

    李丹

    2015-01-01

    <正>The Tragedy of Hamlet dramatizes the revenge Prince Hamlet exacts on his uncle Claudius for murdering King Hamlet,Claudius’s brother and Prince Hamlet’s father,and then succeeding to the throne and taking as his wife Gertrude,the old king’s widow and Prince Hamlet’s mother.This paper will discuss something about dominant voice in the play.Dominant voice is the major voice in the country,the society,or the whole world.Those people who have the power or

  2. Vision Loss, Sudden

    Science.gov (United States)

    ... of age-related macular degeneration. Spotlight on Aging: Vision Loss in Older People Most commonly, vision loss ... Some Causes and Features of Sudden Loss of Vision Cause Common Features* Tests Sudden loss of vision ...

  3. Healthy Vision Tips

    Science.gov (United States)

    ... NEI for Kids > Healthy Vision Tips All About Vision About the Eye Ask a Scientist Video Series ... Links to More Information Optical Illusions Printables Healthy Vision Tips Healthy vision starts with you! Use these ...

  4. Ambient cosmology and spacetime singularities

    CERN Document Server

    Antoniadis, Ignatios

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary.

  5. Ambient cosmology and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios [Bern University, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland); Ecole Polytechnique, Palaiseau (France); Cotsakis, Spiros [CERN, Theory Division, Department of Physics, Geneva 23 (Switzerland); National Technical University, School of Applied Mathematics and Physical Sciences, Athens (Greece)

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary. (orig.)

  6. Singularity Theory and its Applications

    CERN Document Server

    Stewart, Ian; Mond, David; Montaldi, James

    1991-01-01

    A workshop on Singularities, Bifuraction and Dynamics was held at Warwick in July 1989, as part of a year-long symposium on Singularity Theory and its applications. The proceedings fall into two halves: Volume I mainly on connections with algebraic geometry and volume II on connections with dynamical systems theory, bifurcation theory and applications in the sciences. The papers are original research, stimulated by the symposium and workshop: All have been refereed and none will appear elsewhere. The main topic of volume II is new methods for the study of bifurcations in nonlinear dynamical systems, and applications of these.

  7. Laser Singular Theta-Pinch

    CERN Document Server

    Okulov, A Yu

    2009-01-01

    The interaction of the two counter-propagating ultrashort laser pulses of a picosecond duration with a singular wavefronts in the thin slice of the underdense plasma is considered. It is shown that ion-acoustic wave excited via Brillouin three-wave resonance by corkscrew interference pattern acts as a rotating solenoid generating kilogauss quasi-static magnetic fields. The orbital angular momentum carried by light is imprinted into an ion-acoustic liquid. The exact analytical configurations for an ion-acoustic wave current and magnetic field are given for a general class of a paraxial singular beams with an integer topological charges. The range of experimentally accessible parameters is evaluated.

  8. Blindness and vision loss

    Science.gov (United States)

    ... means you cannot see anything and DO NOT see light. (Most people who use the term "blindness" mean ... the vision loss. For long-term vision loss, see a low-vision specialist, who can help you learn to care for yourself and ... of vision; No light perception (NLP); Low vision; Vision loss and blindness ...

  9. Visions and visioning in foresight activities

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Grosu, Dan

    2007-01-01

    The paper discusses the roles of visioning processes and visions in foresight activities and in societal discourses and changes parallel to or following foresight activities. The overall topic can be characterised as the dynamics and mechanisms that make visions and visioning processes work...... or not work. The theoretical part of the paper presents an actor-network theory approach to the analyses of visions and visioning processes, where the shaping of the visions and the visioning and what has made them work or not work is analysed. The empirical part is based on analyses of the roles of visions...... and visioning processes in a number of foresight processes from different societal contexts. The analyses have been carried out as part of the work in the COST A22 network on foresight. A vision is here understood as a description of a desirable or preferable future, compared to a scenario which is understood...

  10. Ethnographic Voice Memo Narratives

    DEFF Research Database (Denmark)

    Rasmussen, Mette Apollo; Conradsen, Maria Bosse

    1800-01-01

    -based technique which actively involves actors in producing ethnography-based data concerning their everyday practice. With the help from smartphone technology it is possible to complement ethnography-based research methods when involving the actors and having them create small voice memo narratives. The voice...... memos create insights of actors‟ everyday practice, without the direct presence of a researcher and could be considered a step towards meeting the dilemmas of research in complex fieldwork settings....

  11. Singularity: Raychaudhuri equation once again

    Indian Academy of Sciences (India)

    Naresh Dadhich

    2007-07-01

    I first recount Raychaudhuri's deep involvement with the singularity problem in general relativity. I then argue that precisely the same situation has arisen today in loop quantum cosmology as obtained when Raychaudhuri discovered his celebrated equation. We thus need a new analogue of the Raychaudhuri equation in quantum gravity.

  12. Singularity: zijn wij technologisch upgradable

    NARCIS (Netherlands)

    drs. Frans van den Reep

    2013-01-01

    1e alinea column: Ik wil een paar dingen kwijt over singularity en de hele horde van buitengewoon slimme mensen die daar vorm aan geven. Aanleiding hiervoor is de speech van Peter Diamandis, cofounder en chairman of the Singularty University, Nasa Research Park, Silicon Valley, die hij vorige week

  13. Lightlike singularities in compactified supergravity

    NARCIS (Netherlands)

    Baal, P. van; Bais, F.A.

    1983-01-01

    We discuss the (causal) structure of a recently found black hole solution of compatified d = 11 supergravity. It is shown that the singularity is in fact lightlike and coincides with the horizon. Consequences are that the Hawking temperature is undetermined and that there is no other universe connec

  14. Singularity: zijn wij technologisch upgradable

    NARCIS (Netherlands)

    drs. Frans van den Reep

    2013-01-01

    1e alinea column: Ik wil een paar dingen kwijt over singularity en de hele horde van buitengewoon slimme mensen die daar vorm aan geven. Aanleiding hiervoor is de speech van Peter Diamandis, cofounder en chairman of the Singularty University, Nasa Research Park, Silicon Valley, die hij vorige week i

  15. Lightlike singularities in compactified supergravity

    NARCIS (Netherlands)

    Baal, P. van; Bais, F.A.

    1983-01-01

    We discuss the (causal) structure of a recently found black hole solution of compatified d = 11 supergravity. It is shown that the singularity is in fact lightlike and coincides with the horizon. Consequences are that the Hawking temperature is undetermined and that there is no other universe connec

  16. Singularities in Speckled Speckle: Screening

    CERN Document Server

    Kessler, David A

    2008-01-01

    We study screening of optical singularities in random optical fields with two widely different length scales. We call the speckle patterns generated by such fields speckled speckle, because the major speckle spots in the pattern are themselves highly speckled. We study combinations of fields whose components exhibit short- and long-range correlations, and find unusual forms of screening.

  17. Singularity: zijn wij technologisch upgradable

    NARCIS (Netherlands)

    Reep, Frans van der

    2013-01-01

    1e alinea column: Ik wil een paar dingen kwijt over singularity en de hele horde van buitengewoon slimme mensen die daar vorm aan geven. Aanleiding hiervoor is de speech van Peter Diamandis, cofounder en chairman of the Singularty University, Nasa Research Park, Silicon Valley, die hij vorige week i

  18. Industrial vision

    DEFF Research Database (Denmark)

    Knudsen, Ole

    1998-01-01

    of an implementation in real production environments. The theory for projection of world points into images is concentrated upon the direct linear transformation (DLT), also called the Extended Pinhole model, and the stability of this method. A complete list of formulas for calculating all parameters in the model...... is present ed, and the variability of the parameters is examined and described. The concept of using CAD together with vision information is based on the fact that all items processed at OSS have an associated complete 3D CAD model that is accessible at all production states. This concept gives numerous...... possibilities for using vision in applications which otherwise would be very difficult to automate. The requirement for low tolerances in production is, despite the huge dimensions of the items involved, extreme. This fact makes great demands on the ability to do robust sub pixel estimation. A new method based...

  19. Pleiades Visions

    Science.gov (United States)

    Whitehouse, M.

    2016-01-01

    Pleiades Visions (2012) is my new musical composition for organ that takes inspiration from traditional lore and music associated with the Pleiades (Seven Sisters) star cluster from Australian Aboriginal, Native American, and Native Hawaiian cultures. It is based on my doctoral dissertation research incorporating techniques from the fields of ethnomusicology and cultural astronomy; this research likely represents a new area of inquiry for both fields. This large-scale work employs the organ's vast sonic resources to evoke the majesty of the night sky and the expansive landscapes of the homelands of the above-mentioned peoples. Other important themes in Pleiades Visions are those of place, origins, cosmology, and the creation of the world.

  20. Cartesian visions.

    Science.gov (United States)

    Fara, Patricia

    2008-12-01

    Few original portraits exist of René Descartes, yet his theories of vision were central to Enlightenment thought. French philosophers combined his emphasis on sight with the English approach of insisting that ideas are not innate, but must be built up from experience. In particular, Denis Diderot criticised Descartes's views by describing how Nicholas Saunderson--a blind physics professor at Cambridge--relied on touch. Diderot also made Saunderson the mouthpiece for some heretical arguments against the existence of God.

  1. Lambda Vision

    Science.gov (United States)

    Czajkowski, Michael

    2014-06-01

    There is an explosion in the quantity and quality of IMINT data being captured in Intelligence Surveillance and Reconnaissance (ISR) today. While automated exploitation techniques involving computer vision are arriving, only a few architectures can manage both the storage and bandwidth of large volumes of IMINT data and also present results to analysts quickly. Lockheed Martin Advanced Technology Laboratories (ATL) has been actively researching in the area of applying Big Data cloud computing techniques to computer vision applications. This paper presents the results of this work in adopting a Lambda Architecture to process and disseminate IMINT data using computer vision algorithms. The approach embodies an end-to-end solution by processing IMINT data from sensors to serving information products quickly to analysts, independent of the size of the data. The solution lies in dividing up the architecture into a speed layer for low-latent processing and a batch layer for higher quality answers at the expense of time, but in a robust and fault-tolerant way. This approach was evaluated using a large corpus of IMINT data collected by a C-130 Shadow Harvest sensor over Afghanistan from 2010 through 2012. The evaluation data corpus included full motion video from both narrow and wide area field-of-views. The evaluation was done on a scaled-out cloud infrastructure that is similar in composition to those found in the Intelligence Community. The paper shows experimental results to prove the scalability of the architecture and precision of its results using a computer vision algorithm designed to identify man-made objects in sparse data terrain.

  2. On the concept of spectral singularities

    Indian Academy of Sciences (India)

    Gusein Sh Guseinov

    2009-09-01

    In this paper, we discuss the concept of spectral singularities for non-Hermitian Hamiltonians. We exihibit spectral singularities of some well-known concrete Hamiltonians with complex-valued coefficients.

  3. Artificial vision.

    Science.gov (United States)

    Zarbin, M; Montemagno, C; Leary, J; Ritch, R

    2011-09-01

    A number treatment options are emerging for patients with retinal degenerative disease, including gene therapy, trophic factor therapy, visual cycle inhibitors (e.g., for patients with Stargardt disease and allied conditions), and cell transplantation. A radically different approach, which will augment but not replace these options, is termed neural prosthetics ("artificial vision"). Although rewiring of inner retinal circuits and inner retinal neuronal degeneration occur in association with photoreceptor degeneration in retinitis pigmentosa (RP), it is possible to create visually useful percepts by stimulating retinal ganglion cells electrically. This fact has lead to the development of techniques to induce photosensitivity in cells that are not light sensitive normally as well as to the development of the bionic retina. Advances in artificial vision continue at a robust pace. These advances are based on the use of molecular engineering and nanotechnology to render cells light-sensitive, to target ion channels to the appropriate cell type (e.g., bipolar cell) and/or cell region (e.g., dendritic tree vs. soma), and on sophisticated image processing algorithms that take advantage of our knowledge of signal processing in the retina. Combined with advances in gene therapy, pathway-based therapy, and cell-based therapy, "artificial vision" technologies create a powerful armamentarium with which ophthalmologists will be able to treat blindness in patients who have a variety of degenerative retinal diseases.

  4. Singular Soliton Operators and Indefinite Metrics

    OpenAIRE

    Grinevich, P. G.; Novikov, S. P.

    2011-01-01

    The singular real second order 1D Schrodinger operators are considered here with such potentials that all local solutions near singularities to the eigenvalue problem are meromorphic for all values of the spectral parameter. All algebro-geometrical or "singular finite-gap" potentials satisfy to this condition. A Spectral Theory is constructed here for the periodic and rapidly decreasing cases in the special classes of functions with singularities and indefinite inner product. It has a finite ...

  5. Free string evolution across plane wave singularities

    CERN Document Server

    Craps, Ben; Evnin, Oleg

    2009-01-01

    In these proceedings, we summarize our studies of free string propagation in (near-)singular scale-invariant plane wave geometries. We analyze the singular limit of the evolution for the center-of-mass motion and all excited string modes. The requirement that the entire excitation energy of the string should be finite excludes consistent propagation across the singularity, in case no dimensionful scales are introduced at the singular locus (in an otherwise scale-invariant space-time).

  6. Singular integral on bounded strictly pseudoconvex domain

    Institute of Scientific and Technical Information of China (English)

    GONG Ding-dong

    2008-01-01

    Kytmanov and Myslivets gave a special Cauchy principal value of the singular integral on the bounded strictly pseudoconvex domain with smooth boundary. By means of this Cauchy integral principal value, the corresponding singular integral and a composition formula are obtained. This composition formula is quite different from usual ones in form. As an application, the corresponding singular integral equation and the system of singular integral equations are discussed as well.

  7. Singularities from colliding plane gravitational waves

    Science.gov (United States)

    Tipler, Frank J.

    1980-12-01

    A simple geometrical argument is given which shows that a collision between two plane gravitational waves must result in singularities. The argument suggests that these singularities are a peculiar feature of plane waves, because singularities are also a consequence of a collision between self-gravitating plane waves of other fields with arbitrarily small energy density.

  8. Singularities from colliding plane gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, F.J.

    1980-12-15

    A simple geometrical argument is given which shows that a collision between two plane gravitational waves must result in singularities. The argument suggests that these singularities are a peculiar feature of plane waves, because singularities are also a consequence of a collision between self-gravitating plane waves of other fields with arbitrarily small energy density.

  9. Singularity development and supersymmetry in holography

    Science.gov (United States)

    Buchel, Alex

    2017-08-01

    We study the effects of supersymmetry on singularity development scenario in holography presented in [1] (BBL). We argue that the singularity persists in a supersymmetric extension of the BBL model. The challenge remains to find a string theory embedding of the singularity mechanism.

  10. Numerical Quadrature of Periodic Singular Integral Equations

    DEFF Research Database (Denmark)

    Krenk, Steen

    1978-01-01

    This paper presents quadrature formulae for the numerical integration of a singular integral equation with Hilbert kernel. The formulae are based on trigonometric interpolation. By integration a quadrature formula for an integral with a logarithmic singularity is obtained. Finally...... it is demonstrated how a singular integral equation with infinite support can be solved by use of the preceding formulae....

  11. Voice Matching Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Abhishek Bal

    2014-03-01

    Full Text Available In this paper, the use of Genetic Algorithm (GA for voice recognition is described. The practical application of Genetic Algorithm (GA to the solution of engineering problem is a rapidly emerging approach in the field of control engineering and signal processing. Genetic algorithms are useful for searching a space in multi-directional way from large spaces and poorly defined space. Voice is a signal of infinite information. Digital processing of voice signal is very important for automatic voice recognition technology. Nowadays, voice processing is very much important in security mechanism due to mimicry characteristic. So studying the voice feature extraction in voice processing is very necessary in military, hospital, telephone system, investigation bureau and etc. In order to extract valuable information from the voice signal, make decisions on the process, and obtain results, the data needs to be manipulated and analyzed. In this paper, if the instant voice is not matched with same person’s reference voices in the database, then Genetic Algorithm (GA is applied between two randomly chosen reference voices. Again the instant voice is compared with the result of Genetic Algorithm (GA which is used, including its three main steps: selection, crossover and mutation. We illustrate our approach with different sample of voices from human in our institution.

  12. Multidimensional singular integrals and integral equations

    CERN Document Server

    Mikhlin, Solomon Grigorievich; Stark, M; Ulam, S

    1965-01-01

    Multidimensional Singular Integrals and Integral Equations presents the results of the theory of multidimensional singular integrals and of equations containing such integrals. Emphasis is on singular integrals taken over Euclidean space or in the closed manifold of Liapounov and equations containing such integrals. This volume is comprised of eight chapters and begins with an overview of some theorems on linear equations in Banach spaces, followed by a discussion on the simplest properties of multidimensional singular integrals. Subsequent chapters deal with compounding of singular integrals

  13. Voice Therapy Practices and Techniques: A Survey of Voice Clinicians.

    Science.gov (United States)

    Mueller, Peter B.; Larson, George W.

    1992-01-01

    Eighty-three voice disorder therapists' ratings of statements regarding voice therapy practices indicated that vocal nodules are the most frequent disorder treated; vocal abuse and hard glottal attack elimination, counseling, and relaxation were preferred treatment approaches; and voice therapy is more effective with adults than with children.…

  14. Voice in early glottic cancer compared to benign voice pathology

    NARCIS (Netherlands)

    Van Gogh, C. D. L.; Mahieu, H. F.; Kuik, D. J.; Rinkel, R. N. P. M.; Langendijk, J. A.; Verdonck-de Leeuw, I. M.

    2007-01-01

    The purpose of this study is to compare (Dutch) Voice Handicap Index (VHIvumc) scores from a selected group of patients with voice problems after treatment for early glottic cancer with patients with benign voice disorders and subjects from the normal population. The study included a group of 35 pat

  15. The inner voice

    Directory of Open Access Journals (Sweden)

    Anthony James Ridgway

    2009-12-01

    Full Text Available The inner voice- we all know what it is because we all have it and use it when we are thinking or reading, for example. Little work has been done on it in our field, with the notable exception of Brian Tomlinson, but presumably it must be a cognitive phenomenon which is of great importance in thinking, language learning, and reading in a foreign language. The inner voice will be discussed as a cognitive psychological phenomenon associated with short-term memory, and distinguished from the inner ear. The process of speech recoding will be examined (the process of converting written language into the inner voice and the importance of developing the inner voice, as a means of both facilitating the production of a new language and enhancing the comprehension of a text in a foreign language, will be emphasized. Finally, ways of developing the inner voice in beginning and intermediate readers of a foreign language will be explored and recommended.

  16. Singularities formation, structure, and propagation

    CERN Document Server

    Eggers, J

    2015-01-01

    Many key phenomena in physics and engineering are described as singularities in the solutions to the differential equations describing them. Examples covered thoroughly in this book include the formation of drops and bubbles, the propagation of a crack and the formation of a shock in a gas. Aimed at a broad audience, this book provides the mathematical tools for understanding singularities and explains the many common features in their mathematical structure. Part I introduces the main concepts and techniques, using the most elementary mathematics possible so that it can be followed by readers with only a general background in differential equations. Parts II and III require more specialised methods of partial differential equations, complex analysis and asymptotic techniques. The book may be used for advanced fluid mechanics courses and as a complement to a general course on applied partial differential equations.

  17. Energy conditions and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, F.J.

    1978-05-15

    In this paper, a number of theorems are proven which collectively show that singularities will occur in spacetime under weaker energy conditions than the strong energy condition. In particular, the Penrose theorem, which uses only the weak energy condition but which applies only to open universes, is extended to all closed universes which have a Cauchy surface whose universal covering manifold is not a three-sphere. Furthermore, it is shown that the strong energy condition in the Hawking-Penrose theorem can be replaced by the weak energy condition and the assumption that the strong energy condition holds only on the average. In addition, it is demonstrated that if the Universe is closed, then the existence of singularities follows from the averaged strong energy condition alone. It is argued that any globally hyperbolic spacetime which satisfies the weak energy condition and which contains a black hole must be null geodesically incomplete.

  18. Singularities in fully developed turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Shivamoggi, Bhimsen K., E-mail: bhimsen.shivamoggi@ucf.edu

    2015-09-18

    Phenomenological arguments are used to explore finite-time singularity (FTS) development in different physical fully-developed turbulence (FDT) situations. Effects of spatial intermittency and fluid compressibility in three-dimensional (3D) FDT and the role of the divorticity amplification mechanism in two-dimensional (2D) FDT and quasi-geostrophic FDT and the advection–diffusion mechanism in magnetohydrodynamic turbulence are considered to provide physical insights into the FTS development in variant cascade physics situations. The quasi-geostrophic FDT results connect with the 2D FDT results in the barotropic limit while they connect with 3D FDT results in the baroclinic limit and hence apparently provide a bridge between 2D and 3D. - Highlights: • Finite-time singularity development in turbulence situations is phenomenologically explored. • Spatial intermittency and compressibility effects are investigated. • Quasi-geostrophic turbulence is shown to provide a bridge between two-dimensional and three-dimensional cases.

  19. Smartphone App for Voice Disorders

    Science.gov (United States)

    ... on. Feature: Taste, Smell, Hearing, Language, Voice, Balance Smartphone App for Voice Disorders Past Issues / Fall 2013 ... developed a mobile monitoring device that relies on smartphone technology to gather a week's worth of talking, ...

  20. Shadow of a naked singularity

    Science.gov (United States)

    Ortiz, Néstor; Sarbach, Olivier; Zannias, Thomas

    2015-08-01

    We analyze the redshift suffered by photons originating from an external source, traversing a collapsing dust cloud, and finally being received by an asymptotic observer. In addition, we study the shadow that the collapsing cloud casts on the sky of the asymptotic observer. We find that the resulting redshift and properties of the shadow depend crucially on whether the final outcome of the complete gravitational collapse is a black hole or a naked singularity. In the black hole case, the shadow is due to the high redshift acquired by the photons as they approach the event horizon, implying that their energy is gradually redshifted toward zero within a few crossing times associated with the event horizon radius. In contrast to this, a naked singularity not only absorbs photons originating from the source, but it also emits infinitely redshifted photons with and without angular momenta. This emission introduces an abrupt cutoff in the frequency shift of the photons detected in directions close to the radial one, and it is responsible for the shadow masking the source in the naked singularity case. Furthermore, even though the shadow forms and begins to grow immediately after the observer crosses the Cauchy horizon, it takes many more crossing times than in the black hole case for the source to be occulted from the observer's eyes. We discuss possible implications of our results for testing the weak cosmic censorship hypothesis. Even though at late times the image of the source perceived by the observer looks the same in both cases, the dynamical formation of the shadow and the redshift images has distinct features and time scales in the black hole versus the naked singularity case. For stellar collapse, these time scales seem to be too short to be resolved with existing technology. However, our results may be relevant for the collapse of seeds leading to supermassive black holes.

  1. Singularities in Speckled Speckle: Statistics

    CERN Document Server

    Freund, Isaac

    2008-01-01

    Random optical fields with two widely different correlation lengths generate far field speckle spots that are themselves highly speckled. We call such patterns speckled speckle, and study their critical points (singularities and stationary points) using analytical theory and computer simulations. We find anomalous spatial arrangements of the critical points and orders of magnitude anomalies in their relative number densities, and in the densities of the associated zero crossings.

  2. Singularity Problem in Teleparallel Dark Energy Models

    CERN Document Server

    Geng, Chao-Qiang; Lee, Chung-Chi

    2013-01-01

    We study the singularity problem in teleparallel dark energy models. A future singularity may occur due to the non-minimal coupling of the dark energy scalar field to teleparallel gravity that effectively changes the gravitational coupling strength and can even make it diverge. This singularity may be avoided by a binding-type self-potential that keeps the scalar field away from the singularity point. For demonstration we analyze the model with a quadratic potential and show how the (non)occurrence of the singularity depends on the initial conditions and the steepness of the potential, both of which affect the competition between the self-interaction and the non-minimal coupling. To examine the capability of the binding-type potential to fit observational data and meanwhile to avoid the singularity, we perform the data fitting for this model and show that the observationally viable region up to the $3\\sigma$ confidence level is free of the future singularity.

  3. On the Milnor fibers of sandwiched singularities

    CERN Document Server

    Nemethi, Andras

    2009-01-01

    The sandwiched surface singularities are those rational surface singularities which dominate birationally smooth surface singularities. de Jong and van Straten showed that one can reduce the study of the deformations of a sandwiched surface singularity to the study of deformations of a 1-dimensional object, a so-called decorated plane curve singularity. In particular, the Milnor fibers corresponding to their various smoothing components may be reconstructed up to diffeomorphisms from those deformations of associated decorated curves which have only ordinary singularities. Part of the topology of such a deformation is encoded in the incidence matrix between the irreducible components of the deformed curve and the points which decorate it, well-defined up to permutations of columns. Extending a previous theorem ofours, which treated the case of cyclic quotient singularities, we show that the Milnor fibers which correspond to deformations whose incidence matrices are different up to permutations of columns are n...

  4. Non-singular dislocation fields

    Energy Technology Data Exchange (ETDEWEB)

    Aifantis, Elias C, E-mail: mom@mom.gen.auth.gr [Laboratory of Mechanics and Materials, Faculty of Engineering, Aristotle University of Thessaloniki, GR-54124, Thessaloniki (Greece); Center for Mechanics of Materials, Michigan Technological University, Houghton MI 49931 (United States)

    2009-07-15

    Non-singular solutions for dislocation and disclination fields have recently been obtained by the author and his co-workers by using a robust model of gradient elasticity theory. These solutions, whose form is simple and easy to implement, are obtained by reducing the gradient elasticity problem to a corresponding linear elasticity boundary value problem through the solutions of an inhomogeneous Helmholtz equation where the source term is the classical singular solution. The Laplacian in the Helmholtz equation, involving the extra gradient coefficient, produces a new term in the gradient solution which asymptotically approaches the negative of the classical elasticity solution on the dislocation line. Thus, the singularity is eliminated and an arbitrary estimate of the dislocation core size introduced in classical theory, is not required. These predictions are tested against atomistic calculations and their implications to various dislocation related configurations are discussed. Due to the simple and elegant form of these solutions, it is hoped that they will be useful in discrete dislocation dynamics simulations.

  5. Stringy Resolutions of Null Singularities

    Energy Technology Data Exchange (ETDEWEB)

    Fabinger, Michal

    2003-02-06

    We study string theory in supersymmetric time-dependent backgrounds. In the framework of general relativity, supersymmetry for spacetimes without flux implies the existence of a covariantly constant null vector, and a relatively simple form of the metric. As a result, the local nature of any such spacetime can be easily understood. We show that we can view any such geometry as a sequence of solutions to lower-dimensional Euclidean gravity. If we choose the lower-dimensional solutions to degenerate at some light-cone time, we obtain null singularities, which may be thought of as generalizations of the parabolic orbifold singularity. We find that in string theory, many such null singularities get repaired by {alpha}{prime}-corrections--in particular, by worldsheet instantons. As a consequence, the resulting string theory solutions do not suffer from any instability. Even though the CFT description of these solutions is not always valid, they can still be well understood after taking the effects of light D-branes into account; the breakdown of the worldsheet conformal field theory is purely gauge-theoretic, not involving strong gravitational effects.

  6. Pediatric Low Vision

    Science.gov (United States)

    ... Asked Questions Español Condiciones Chinese Conditions Pediatric Low Vision What is Low Vision? Partial vision loss that cannot be corrected causes ... and play. What are the signs of Low Vision? Some signs of low vision include difficulty recognizing ...

  7. Low Vision FAQs

    Science.gov (United States)

    ... de los Ojos Cómo hablarle a su oculista Low Vision FAQs What is low vision? Low vision is a visual impairment, not ... person’s ability to perform everyday activities. What causes low vision? Low vision can result from a variety ...

  8. Color vision.

    Science.gov (United States)

    Gegenfurtner, Karl R; Kiper, Daniel C

    2003-01-01

    Color vision starts with the absorption of light in the retinal cone photoreceptors, which transduce electromagnetic energy into electrical voltages. These voltages are transformed into action potentials by a complicated network of cells in the retina. The information is sent to the visual cortex via the lateral geniculate nucleus (LGN) in three separate color-opponent channels that have been characterized psychophysically, physiologically, and computationally. The properties of cells in the retina and LGN account for a surprisingly large body of psychophysical literature. This suggests that several fundamental computations involved in color perception occur at early levels of processing. In the cortex, information from the three retino-geniculate channels is combined to enable perception of a large variety of different hues. Furthermore, recent evidence suggests that color analysis and coding cannot be separated from the analysis and coding of other visual attributes such as form and motion. Though there are some brain areas that are more sensitive to color than others, color vision emerges through the combined activity of neurons in many different areas.

  9. A rapid local singularity analysis algorithm with applications

    Science.gov (United States)

    Chen, Zhijun; Cheng, Qiuming; Agterberg, Frits

    2015-04-01

    The local singularity model developed by Cheng is fast gaining popularity in characterizing mineralization and detecting anomalies of geochemical, geophysical and remote sensing data. However in one of the conventional algorithms involving the moving average values with different scales is time-consuming especially while analyzing a large dataset. Summed area table (SAT), also called as integral image, is a fast algorithm used within the Viola-Jones object detection framework in computer vision area. Historically, the principle of SAT is well-known in the study of multi-dimensional probability distribution functions, namely in computing 2D (or ND) probabilities (area under the probability distribution) from the respective cumulative distribution functions. We introduce SAT and it's variation Rotated Summed Area Table in the isotropic, anisotropic or directional local singularity mapping in this study. Once computed using SAT, any one of the rectangular sum can be computed at any scale or location in constant time. The area for any rectangular region in the image can be computed by using only 4 array accesses in constant time independently of the size of the region; effectively reducing the time complexity from O(n) to O(1). New programs using Python, Julia, matlab and C++ are implemented respectively to satisfy different applications, especially to the big data analysis. Several large geochemical and remote sensing datasets are tested. A wide variety of scale changes (linear spacing or log spacing) for non-iterative or iterative approach are adopted to calculate the singularity index values and compare the results. The results indicate that the local singularity analysis with SAT is more robust and superior to traditional approach in identifying anomalies.

  10. Sustainable Consumer Voices

    DEFF Research Database (Denmark)

    Klitmøller, Anders; Rask, Morten; Jensen, Nevena

    2011-01-01

    Aiming to explore how user driven innovation can inform high level design strategies, an in-depth empirical study was carried out, based on data from 50 observations of private vehicle users. This paper reports the resulting 5 consumer voices: Technology Enthusiast, Environmentalist, Design Lover......, Pragmatist and Status Seeker. Expedient use of the voices in creating design strategies is discussed, thus contributing directly to the practice of high level design managers. The main academic contribution of this paper is demonstrating how applied anthropology can be used to generate insights...... into disruptive emergence of product service systems, where quantitative user analyses rely on historical continuation....

  11. VoiceRelay: voice key operation using visual basic.

    Science.gov (United States)

    Abrams, Lise; Jennings, David T

    2004-11-01

    Using a voice key is a popular method for recording vocal response times in a variety of language production tasks. This article describes a class module called VoiceRelay that can be easily utilized in Visual Basic programs for voice key operation. This software-based voice key offers the precision of traditional voice keys (although accuracy is system dependent), as well as the flexibility of volume and sensitivity control. However, VoiceRelay is a considerably less expensive alternative for recording vocal response times because it operates with existing PC hardware and does not require the purchase of external response boxes or additional experiment-generation software. A sample project demonstrating implementation of the VoiceRelay class module may be downloaded from the Psychonomic Society Web archive, www.psychonomic.org/archive.

  12. Impairments to Vision

    Science.gov (United States)

    ... an external Non-Government web site. Impairments to Vision Normal Vision Diabetic Retinopathy Age-related Macular Degeneration In this ... pictures, fixate on the nose to simulate the vision loss. In diabetic retinopathy, the blood vessels in ...

  13. Color vision test

    Science.gov (United States)

    ... present from birth) color vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling ... Vision test - color; Ishihara color vision test Images Color blindness tests References Bowling B. Hereditary fundus dystrophies. In: ...

  14. Mathematical models with singularities a zoo of singular creatures

    CERN Document Server

    Torres, Pedro J

    2015-01-01

    The book aims to provide an unifying view of a variety (a 'zoo') of mathematical models with some kind of singular nonlinearity, in the sense that it becomes infinite when the state variable approaches a certain point. Up to 11 different concrete models are analyzed in separate chapters. Each chapter starts with a discussion of the basic model and its physical significance. Then the main results and typical proofs are outlined, followed by open problems. Each chapter is closed by a suitable list of references. The book may serve as a guide for researchers interested in the modelling of real world processes.

  15. Assessment voice synthesizers for reading in digital books

    Directory of Open Access Journals (Sweden)

    Sérvulo Fernandes da Silva Neto

    2013-07-01

    Full Text Available The digital accessibility shows ways to information access in digital media that assist people with different types of disabilities to a better interaction with the computer independent of its limitations. Of these tools are composed by voice synthesizers, that supposedly simplifying their access to any recorded knowledge through digital technologies. However such tools have emerged originally in countries foreign language. Which brings us to the following research problem: the voice synthesizers are appropriate for reading digital books in the Portuguese language? The objective of this study was to analyze and classify different software tools voice synthesizers in combination with software digital book readers to support accessibility to e-books in Portuguese. Through literature review were identified applications software voice synthesizers, composing the sample analyzed in this work. We used a simplified version of the method of Multiple Criteria Decision Support - MMDA, to assess these. In the research 12 were considered readers of e-books and 11 software voice synthesizer, tested with six formats of e-books (E-pub, PDF, HTML, DOC, TXT, and Mobi. In accordance with the results, the software Virtual Vision achieved the highest score. Relative to formats, it was found that the PDF has measured a better score when summed the results of the three synthesizers. In the studied universe contacted that many synthesizers simply cannot be used because they did not support the Portuguese language.

  16. Artificial vision.

    Science.gov (United States)

    Humayun, M S; de Juan, E

    1998-01-01

    Outer retinal degenerations such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD) lead to blindness because of photoreceptor degeneration. To test whether controlled electrical stimulation of the remaining retinal neurons could provide form vision, we electrically stimulated the inner retinal surface with micro-electrodes inserted through the sclera/eye wall of 14 of these patients (12 RP and 2 AMD). This procedure was performed in the operating room under local anaesthesia and all responses were recorded via a video camera mounted on the surgical microscope. Electrical stimulation of the inner retinal surface elicited visual perception of a spot of light (phosphene) in all subjects. This perception was retinotopically correct in 13 of 14 patients. In a resolution test in a subject with no light perception, the patient could resolve phosphenes at 1.75 degrees centre-to-centre distance (i.e. visual acuity compatible with mobility; Snellen visual acuity of 4/200).

  17. Voice application development for Android

    CERN Document Server

    McTear, Michael

    2013-01-01

    This book will give beginners an introduction to building voice-based applications on Android. It will begin by covering the basic concepts and will build up to creating a voice-based personal assistant. By the end of this book, you should be in a position to create your own voice-based applications on Android from scratch in next to no time.Voice Application Development for Android is for all those who are interested in speech technology and for those who, as owners of Android devices, are keen to experiment with developing voice apps for their devices. It will also be useful as a starting po

  18. Sustainable Consumer Voices

    DEFF Research Database (Denmark)

    Klitmøller, Anders; Rask, Morten; Jensen, Nevena

    2011-01-01

    Aiming to explore how user driven innovation can inform high level design strategies, an in-depth empirical study was carried out, based on data from 50 observations of private vehicle users. This paper reports the resulting 5 consumer voices: Technology Enthusiast, Environmentalist, Design Lover...

  19. Voices of courage

    Directory of Open Access Journals (Sweden)

    Noraida Abdullah Karim

    2007-07-01

    Full Text Available In May 2007 the Women’s Commission for Refugee Women and Children1 presented its annual Voices of Courage awards to three displaced people who have dedicated their lives to promoting economic opportunities for refugee and displaced women and youth. These are their (edited testimonies.

  20. Listen to a voice

    DEFF Research Database (Denmark)

    Hølge-Hazelton, Bibi

    2001-01-01

    Listen to the voice of a young girl Lonnie, who was diagnosed with Type 1 diabetes at 16. Imagine that she is deeply involved in the social security system. She lives with her mother and two siblings in a working class part of a small town. She is at a special school for problematic youth, and he...

  1. Political animal voices

    NARCIS (Netherlands)

    Meijer, E.R.

    2017-01-01

    In this thesis, I develop a theory of political animal voices. The first part of the thesis focuses on non-human animal languages and forming interspecies worlds. I first investigate the relation between viewing language as exclusively human and seeing humans as categorically different from other

  2. Finding a Voice

    Science.gov (United States)

    Stuart, Shannon

    2012-01-01

    Schools have struggled for decades to provide expensive augmentative and alternative communication (AAC) resources for autistic students with communication challenges. Clunky voice output devices, often included in students' individualized education plans, cost about $8,000, a difficult expense to cover in hard times. However, mobile technology is…

  3. the Voice of Tomorrow

    Institute of Scientific and Technical Information of China (English)

    AlanBurdick

    2003-01-01

    Have you heard Mide? Coule be.Mike is a professional reader,and he's everywhere these days. On MapQuest, the Web-based map service,he'll read aloud whatever directions you ask for. If you like to have AOL or Yahoo! e-mail read aloud to you over the phone, that's Mike's voice you 're hearing. Soon

  4. What the voice reveals.

    NARCIS (Netherlands)

    Ko, Sei Jin

    2007-01-01

    Given that the voice is our main form of communication, we know surprisingly little about how it impacts judgment and behavior. Furthermore, the modern advancement in telecommunication systems, such as cellular phones, has meant that a large proportion of our everyday interactions are conducted voca

  5. The Inner Voice

    Science.gov (United States)

    Ridgway, Anthony James

    2009-01-01

    The inner voice- we all know what it is because we all have it and use it when we are thinking or reading, for example. Little work has been done on it in our field, with the notable exception of Brian Tomlinson, but presumably it must be a cognitive phenomenon which is of great importance in thinking, language learning, and reading in a foreign…

  6. Moving beyond Youth Voice

    Science.gov (United States)

    Serido, Joyce; Borden, Lynne M.; Perkins, Daniel F.

    2011-01-01

    This study combines research documenting the benefits of positive relationships between youth and caring adults on a young person's positive development with studies on youth voice to examine the mechanisms through which participation in youth programs contributes to positive developmental outcomes. Specifically, the study explores whether youth's…

  7. Bodies and Voices

    DEFF Research Database (Denmark)

    A wide-ranging collection of essays centred on readings of the body in contemporary literary and socio-anthropological discourse, from slavery and rape to female genital mutilation, from clothing, ocular pornography, voice, deformation and transmutation to the imprisoned, dismembered, remembered...

  8. Voices for Careers.

    Science.gov (United States)

    York, Edwin G.; Kapadia, Madhu

    Listed in this annotated bibliography are 502 cassette tapes of value to career exploration for Grade 7 through the adult level, whether as individualized instruction, small group study, or total class activity. Available to New Jersey educators at no charge, this Voices for Careers System is also available for duplication on request from the New…

  9. What the voice reveals

    NARCIS (Netherlands)

    Ko, Sei Jin

    2007-01-01

    Given that the voice is our main form of communication, we know surprisingly little about how it impacts judgment and behavior. Furthermore, the modern advancement in telecommunication systems, such as cellular phones, has meant that a large proportion of our everyday interactions are conducted voca

  10. Bodies and Voices

    DEFF Research Database (Denmark)

    A wide-ranging collection of essays centred on readings of the body in contemporary literary and socio-anthropological discourse, from slavery and rape to female genital mutilation, from clothing, ocular pornography, voice, deformation and transmutation to the imprisoned, dismembered, remembered...

  11. Dimensional Mutation and Spacelike Singularities

    CERN Document Server

    Silverstein, E

    2006-01-01

    I argue that critical string theory on a Riemann surface of genus $h >> 1$ crosses over, when the surface approaches the string scale in size, to a background of supercritical string theory with effective central charge as large as $2h$. Concrete evidence for this proposal is provided by the high energy density of states (realized on the Riemann surface side by strings wrapping nontrivial elements of the fundamental group) and by a linear sigma model which at large $h$ approximates the time evolution through the initial transition. This suggests that cosmological singularities arising in negatively curved FRW backgrounds may be replaced by a phase of supercritical string theory.

  12. Multichannel framework for singular quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Camblong, Horacio E., E-mail: camblong@usfca.edu [Department of Physics and Astronomy, University of San Francisco, San Francisco, CA 94117-1080 (United States); Epele, Luis N., E-mail: epele@fisica.unlp.edu.ar [Laboratorio de Física Teórica, Departamento de Física, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67–1900 La Plata (Argentina); Fanchiotti, Huner, E-mail: huner@fisica.unlp.edu.ar [Laboratorio de Física Teórica, Departamento de Física, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67–1900 La Plata (Argentina); García Canal, Carlos A., E-mail: garcia@fisica.unlp.edu.ar [Laboratorio de Física Teórica, Departamento de Física, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67–1900 La Plata (Argentina); Ordóñez, Carlos R., E-mail: ordonez@uh.edu [Department of Physics, University of Houston, Houston, TX 77204-5506 (United States)

    2014-01-15

    A multichannel S-matrix framework for singular quantum mechanics (SQM) subsumes the renormalization and self-adjoint extension methods and resolves its boundary-condition ambiguities. In addition to the standard channel accessible to a distant (“asymptotic”) observer, one supplementary channel opens up at each coordinate singularity, where local outgoing and ingoing singularity waves coexist. The channels are linked by a fully unitary S-matrix, which governs all possible scenarios, including cases with an apparent nonunitary behavior as viewed from asymptotic distances. -- Highlights: •A multichannel framework is proposed for singular quantum mechanics and analogues. •The framework unifies several established approaches for singular potentials. •Singular points are treated as new scattering channels. •Nonunitary asymptotic behavior is subsumed in a unitary multichannel S-matrix. •Conformal quantum mechanics and the inverse quartic potential are highlighted.

  13. Weyl Anomaly and Initial Singularity Crossing

    CERN Document Server

    Awad, Adel

    2015-01-01

    We consider the role of quantum effects, mainly, Weyl anomaly in modifying FLRW model singular behavior at early times. Weyl anomaly corrections to FLRW models have been considered in the past, here we reconsider this model and show the following: The singularity of this model is weak according to Tipler and Krolak, therefore, the spacetime might admit a geodesic extension. Weyl anomaly corrections changes the nature of the initial singularity from a big bang singularity to a sudden singularity. The two branches of solutions consistent with the semiclassical treatment form a disconnected manifold. Joining these two parts at the singularity provides us with a $C^1$ extension to nonspacelike geodesics and leaves the spacetime geodesically complete. Using Gauss-Codazzi equations one can derive generalized junction conditions for this higher-derivative gravity. The extended spacetime obeys Friedmann and Raychaudhuri equations and the junction conditions. The junction does not generate Dirac delta functions in mat...

  14. Homogeneous spacelike singularities inside spherical black holes

    CERN Document Server

    Burko, L M

    1997-01-01

    Recent numerical simulations have found that the Cauchy horizon inside spherical charged black holes, when perturbed nonlinearly by a self-gravitating, minimally-coupled, massless, spherically-symmetric scalar field, turns into a null weak singularity which focuses monotonically to $r=0$ at late times, where the singularity becomes spacelike. Our main objective is to study this spacelike singularity. We study analytically the spherically-symmetric Einstein-Maxwell-scalar equations asymptotically near the singularity. We obtain a series-expansion solution for the metric functions and for the scalar field near $r=0$ under the simplifying assumption of homogeneity. Namely, we neglect spatial derivatives and keep only temporal derivatives. We find that there indeed exists a generic spacelike singularity solution for these equations (in the sense that the solution depends on enough free parameters), with similar properties to those found in the numerical simulations. This singularity is strong in the Tipler sense,...

  15. Conformal anomaly around the sudden singularity

    CERN Document Server

    Houndjo, S J M

    2010-01-01

    Quantum effects due to particle creation on a classical sudden singularity have been investigated in a previous work. The conclusion was that quantum effects do not lead to the avoidance nor the modification of the sudden future singularity. In this paper, we investigate quantum corrections coming from conformal anomaly near the sudden future singularity. We conclude that when the equation of state is chosen to be $p=-\\rho-A\\rho^\\alpha$, the conformal anomaly can transform the sudden singularity in the singularity of type III for any $\\alpha> 1/2$ and in the singularity of the type I (the big rip) or the big crunch for $1/2<\\alpha<3/2$.

  16. Conformal anomaly around the sudden singularity

    Science.gov (United States)

    Houndjo, S. J. M.

    2010-10-01

    Quantum effects due to particle creation on a classical sudden singularity have been investigated in a previous work. The conclusion was that quantum effects do not lead to the avoidance nor the modification of the sudden future singularity. In this paper, we investigate quantum corrections coming from conformal anomaly near the sudden future singularity. We conclude that when the equation of state is chosen to be p=-ρ-Aρα, the conformal anomaly can transform the sudden singularity into the singularity of type III for any α>1/2 and into the singularity of the type I (the big rip) or the big crunch for 1/2<α<3/2.

  17. The geometry of warped product singularities

    Science.gov (United States)

    Stoica, Ovidiu Cristinel

    In this article, the degenerate warped products of singular semi-Riemannian manifolds are studied. They were used recently by the author to handle singularities occurring in General Relativity, in black holes and at the big-bang. One main result presented here is that a degenerate warped product of semi-regular semi-Riemannian manifolds with the warping function satisfying a certain condition is a semi-regular semi-Riemannian manifold. The connection and the Riemann curvature of the warped product are expressed in terms of those of the factor manifolds. Examples of singular semi-Riemannian manifolds which are semi-regular are constructed as warped products. Applications include cosmological models and black holes solutions with semi-regular singularities. Such singularities are compatible with a certain reformulation of the Einstein equation, which in addition holds at semi-regular singularities too.

  18. Topological resolution of gauge theory singularities

    Energy Technology Data Exchange (ETDEWEB)

    Saracco, Fabio; Tomasiello, Alessandro; Torroba, Gonzalo

    2013-08-21

    Some gauge theories with Coulomb branches exhibit singularities in perturbation theory, which are usually resolved by nonperturbative physics. In string theory this corresponds to the resolution of timelike singularities near the core of orientifold planes by effects from F or M theory. We propose a new mechanism for resolving Coulomb branch singularities in three-dimensional gauge theories, based on Chern-Simons interactions. This is illustrated in a supersymmetric S U ( 2 ) Yang-Mills-Chern-Simons theory. We calculate the one-loop corrections to the Coulomb branch of this theory and find a result that interpolates smoothly between the high-energy metric (that would exhibit the singularity) and a regular singularity-free low-energy result. We suggest possible applications to singularity resolution in string theory and speculate a relationship to a similar phenomenon for the orientifold six-plane in massive IIA supergravity.

  19. Singularity Analysis of Geometric Constraint Systems

    Institute of Scientific and Technical Information of China (English)

    彭小波; 陈立平; 周凡利; 周济

    2002-01-01

    Singularity analysis is an important subject of the geometric constraint sat-isfaction problem. In this paper, three kinds of singularities are described and corresponding identification methods are presented for both under-constrained systems and over-constrained systems. Another special but common singularity for under-constrained geometric systems, pseudo-singularity, is analyzed. Pseudo-singularity is caused by a variety of constraint match ing of under-constrained systems and can be removed by improving constraint distribution. To avoid pseudo-singularity and decide redundant constraints adaptively, a differentiation algo rithm is proposed in the paper. Its correctness and efficiency have been validated through its practical applications in a 2D/3D geometric constraint solver CBA.

  20. Topological resolution of gauge theory singularities

    CERN Document Server

    Saracco, Fabio; Torroba, Gonzalo

    2013-01-01

    Some gauge theories with Coulomb branches exhibit singularities in perturbation theory, which are usually resolved by nonperturbative physics. In string theory this corresponds to the resolution of timelike singularities near the core of orientifold planes by effects from F or M theory. We propose a new mechanism for resolving Coulomb branch singularities in three dimensional gauge theories, based on Chern-Simons interactions. This is illustrated in a supersymmetric SU(2) Yang-Mills-Chern-Simons theory. We calculate the one loop corrections to the Coulomb branch of this theory and find a result that interpolates smoothly between the high energy metric (that would exhibit the singularity) and a regular singularity-free low energy result. We suggest possible applications to singularity resolution in string theory and speculate a relationship to a similar phenomenon for the orientifold six-plane in massive IIA supergravity.

  1. String spectra near some null cosmological singularities

    CERN Document Server

    Madhu, Kallingalthodi

    2009-01-01

    We construct cosmological spacetimes with null Kasner-like singularities as purely gravitational solutions with no other background fields turned on. These can be recast as anisotropic plane-wave spacetimes by coordinate transformations. We analyse string quantization to find the spectrum of string modes in these backgrounds. The classical string modes can be solved for exactly in these time-dependent backgrounds, which enables a detailed study of the near singularity string spectrum, (time-dependent) oscillator masses and wavefunctions. We find that for low lying string modes(finite oscillation number), the classical near-singularity string mode functions are non-divergent for various families of singularities. Furthermore, for any infinitesimal regularization of the vicinity of the singularity, we find a tower of string modes of ultra-high oscillation number which propagate essentially freely in the background. The resulting picture suggests that string interactions are non-negligible near the singularity.

  2. Singularities of Type-Q ABS Equations

    Directory of Open Access Journals (Sweden)

    James Atkinson

    2011-07-01

    Full Text Available The type-Q equations lie on the top level of the hierarchy introduced by Adler, Bobenko and Suris (ABS in their classification of discrete counterparts of KdV-type integrable partial differential equations. We ask what singularities are possible in the solutions of these equations, and examine the relationship between the singularities and the principal integrability feature of multidimensional consistency. These questions are considered in the global setting and therefore extend previous considerations of singularities which have been local. What emerges are some simple geometric criteria that determine the allowed singularities, and the interesting discovery that generically the presence of singularities leads to a breakdown in the global consistency of such systems despite their local consistency property. This failure to be globally consistent is quantified by introducing a natural notion of monodromy for isolated singularities.

  3. Precursory singularities in spherical gravitational collapse

    Science.gov (United States)

    Lake, Kayll

    1992-05-01

    General conditions are developed for the formation of naked precursory ('shell-focusing') singularities in spherical gravitational collapse. These singularities owe their nakedness to the fact that the gravitational potential fails to be single valued prior to the onset of a true gravitational singularity. It is argued that they do not violate the spirit of cosmic censorship. Rather, they may well be an essentially generic feature of relativistic gravitational collapse.

  4. Quantum dress for a naked singularity

    Science.gov (United States)

    Casals, Marc; Fabbri, Alessandro; Martínez, Cristián; Zanelli, Jorge

    2016-09-01

    We investigate semiclassical backreaction on a conical naked singularity space-time with a negative cosmological constant in (2 + 1)-dimensions. In particular, we calculate the renormalized quantum stress-energy tensor for a conformally coupled scalar field on such naked singularity space-time. We then obtain the backreacted metric via the semiclassical Einstein equations. We show that, in the regime where the semiclassical approximation can be trusted, backreaction dresses the naked singularity with an event horizon, thus enforcing (weak) cosmic censorship.

  5. Connections Between Singular Control and Optimal Switching

    OpenAIRE

    Guo, Xin; Tomecek, Pascal

    2007-01-01

    This paper builds a new theoretical connection between singular control of finite variation and optimal switching problems. This correspondence provides a novel method for solving high-dimensional singular control problems, and enables us to extend the theory of reversible investment: sufficient conditions are derived for the existence of optimal controls and for the regularity of value functions. Consequently, our regularity result links singular controls and Dynkin games through sequential ...

  6. Discrete equations and the singular manifold method

    CERN Document Server

    Estévez, P G

    1999-01-01

    The Painleve expansion for the second Painleve equation (PII) and fourth Painleve equation (PIV) have two branches. The singular manifold method therefore requires two singular manifolds. The double singular manifold method is used to derive Miura transformations from PII and PIV to modified Painleve type equations for which auto-Backlund transformations are obtained. These auto-Backlund transformations can be used to obtain discrete equations.

  7. Singularity analysis: theory and further developments

    Science.gov (United States)

    Cheng, Qiuming

    2015-04-01

    Since the concept of singularity and local singularity analysis method (LSA) were originally proposed by the author for characterizing the nonlinear property of hydrothermal mineralization processes, the local singularity analysis technique has been successfully applied for identification of geochemical and geophysical anomalies related to various types of mineral deposits. It has also been shown that the singularity is the generic property of singular geo-processes which result in anomalous amounts of energy release or material accumulation within a narrow spatial-temporal interval. In the current paper we introduce several new developments about singularity analysis. First is a new concept of 'fractal density' which describes the singularity of complex phenomena of fractal nature. While the ordinary density possesses a unit of ratio of mass and volume (e.g. g/cm3, kg/m3) or ratio of energy over volume or time (e.g. J/cm3, w/L3, w/s), the fractal density has a unit of ratio of mass over fractal set or energy over fractal set (e.g. g/cmα, kg/mα, J/ mα, w/Lα, where α can be a non-integer). For the matter with fractal density (a non-integer α), the ordinary density of the phenomena (mass or energy) no longer exists and depicts singularity. We demonstrate that most of extreme geo-processes occurred in the earth crust originated from cascade earth dynamics (mental convection, plate tectonics, orogeny and weathering etc) may cause fractal density of mass accumulation or energy release. The examples to be used to demonstrate the concepts of fractal density and singularity are earthquakes, floods, volcanos, hurricanes, heat flow over oceanic ridge, hydrothermal mineralization in orogenic belt, and anomalies in regolith over mine caused by ore and toxic elements vertical migration. Other developments of singularity theory and methodologies including singular Kriging and singularity weights of evidence model for information integration will also be introduced.

  8. Quantum dress for a naked singularity

    CERN Document Server

    Casals, Marc; Martínez, Cristián; Zanelli, Jorge

    2016-01-01

    We investigate semiclassical backreaction on a conical naked singularity space-time with a negative cosmological constant in (2+1)-dimensions. In particular, we calculate the renormalized quantum stress-energy tensor for a conformally coupled scalar field on such naked singularity space-time. We then obtain the backreacted metric via the semiclassical Einstein equations. We show that, in the regime where the semiclassical approximation can be trusted, backreaction dresses the naked singularity with an event horizon, thus enforcing cosmic censorship.

  9. A singularity theorem based on spatial averages

    Indian Academy of Sciences (India)

    J M M Senovilla

    2007-07-01

    Inspired by Raychaudhuri's work, and using the equation named after him as a basic ingredient, a new singularity theorem is proved. Open non-rotating Universes, expanding everywhere with a non-vanishing spatial average of the matter variables, show severe geodesic incompletness in the past. Another way of stating the result is that, under the same conditions, any singularity-free model must have a vanishing spatial average of the energy density (and other physical variables). This is very satisfactory and provides a clear decisive difference between singular and non-singular cosmologies.

  10. On curves on sandwiched surface singularities

    OpenAIRE

    Fernandez-Sanchez, Jesus

    2007-01-01

    Fixed a point O on a non-singular surface S and a complete mO-primary ideal I in its local ring, the curves on the surface X obtained by blowing-up I are studied in terms of the base points of I. Criteria for the principality of these curves are obtained. New formulas for their multiplicity, intersection numbers and order of singularity at the singularities of X are given. The semigroup of branches going through a sandwiched singularity is effectively determined, too.

  11. Three-qutrit entanglement and simple singularities

    Science.gov (United States)

    Holweck, Frédéric; Jaffali, Hamza

    2016-11-01

    In this paper, we use singularity theory to study the entanglement nature of pure three-qutrit systems. We first consider the algebraic variety X of separable three-qutrit states within the projective Hilbert space {{P}}({ H })={{{P}}}26. Given a quantum pure state | \\varphi > \\in {{P}}({ H }) we define the X φ -hypersuface by cutting X with a hyperplane H φ defined by the linear form ranges over the stochastic local operation and classical communication entanglement classes, the ‘worst’ possible singular X φ -hypersuface with isolated singularities, has a unique singular point of type D 4.

  12. Generalised hyperbolicity in spacetimes with singular submanifolds

    CERN Document Server

    Sanchez, Yafet Sanchez

    2015-01-01

    The idea of defining a gravitational singularity as an obstruction to the dynamical evolution of a test field (described by a PDE) rather than the dynamical evolution of a particle (described by a geodesics) is explored. In this paper we obtain general conditions under which the wave equation is well-posed in spacetimes with weak singularities in which the singularity is concentrated in a submanifold. In particular, the results can be applied to spacetimes with shell-crossing singularities, surface layers and generalised cosmic strings.

  13. On Type I Singularities in Ricci flow

    CERN Document Server

    Enders, Joerg; Topping, Peter M

    2010-01-01

    We define several notions of singular set for Type I Ricci flows and show that they all coincide. In order to do this, we prove that blow-ups around singular points converge to nontrivial gradient shrinking solitons, thus extending work of Naber. As a by-product we conclude that the volume of a finite-volume singular set vanishes at the singular time. We also define a notion of density for Type I Ricci flows and use it to prove a regularity theorem reminiscent of White's partial regularity result for mean curvature flow.

  14. Near Vision Test for Adults

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  15. Singularities of slice regular functions

    CERN Document Server

    Stoppato, Caterina

    2010-01-01

    Beginning in 2006, G. Gentili and D.C. Struppa developed a theory of regular quaternionic functions with properties that recall classical results in complex analysis. For instance, in each Euclidean ball centered at 0 the set of regular functions coincides with that of quaternionic power series converging in the same ball. In 2009 the author proposed a classification of singularities of regular functions as removable, essential or as poles and studied poles by constructing the ring of quotients. In that article, not only the statements, but also the proving techniques were confined to the special case of balls centered at 0. In a subsequent paper, F. Colombo, G. Gentili, I. Sabadini and D.C. Struppa (2009) identified a larger class of domains, on which the theory of regular functions is natural and not limited to quaternionic power series. The present article studies singularities in this new context, beginning with the construction of the ring of quotients and of Laurent-type expansions at points other than ...

  16. Helping Students Develop Vision and Voice: The Role Creativity Plays

    Science.gov (United States)

    Welkener, Michele M.

    2004-01-01

    Most college and university mission statements identify creativity as an important institutional commitment, and most educators would agree that the ideal student is complex and creative. Yet how do students view creativity and what impact might those views have on their ability to accomplish what educators hope for them? In this article, the…

  17. Constructing Professional Identities: Montessori Teachers' Voices and Visions

    Science.gov (United States)

    Malm, Birgitte

    2004-01-01

    In this study, occupational life histories of Montessori teachers in Sweden have been constructed in collaboration with a group of them. Data exploration and analysis have included journals, interviews, written reflections and conversations. Of interest has been to shed light on underlying values, ways in which professional roles reflect personal…

  18. April 16th : The World Voice Day

    NARCIS (Netherlands)

    Svec, Jan G.; Behlau, Mara

    2007-01-01

    Although the voice is used as an everyday basis of speech, most people realize its importance only when a voice problem arises. Increasing public awareness of the importance of the voice and alertness to voice problems are the main goals of the World Voice Day, which is celebrated yearly on April 16

  19. Risk factors for voice problems in teachers

    NARCIS (Netherlands)

    Kooijman, P. G. C.; de Jong, F. I. C. R. S.; Thomas, G.; Huinck, W.; Donders, R.; Graamans, K.; Schutte, H. K.

    2006-01-01

    In order to identify factors that are associated with voice problems and voice-related absenteeism in teachers, 1,878 questionnaires were analysed. The questionnaires inquired about personal data, voice complaints, voice-related absenteeism from work and conditions that may lead to voice complaints

  20. You're a What? Voice Actor

    Science.gov (United States)

    Liming, Drew

    2009-01-01

    This article talks about voice actors and features Tony Oliver, a professional voice actor. Voice actors help to bring one's favorite cartoon and video game characters to life. They also do voice-overs for radio and television commercials and movie trailers. These actors use the sound of their voice to sell a character's emotions--or an advertised…

  1. Risk factors for voice problems in teachers

    NARCIS (Netherlands)

    Kooijman, P. G. C.; de Jong, F. I. C. R. S.; Thomas, G.; Huinck, W.; Donders, R.; Graamans, K.; Schutte, H. K.

    2006-01-01

    In order to identify factors that are associated with voice problems and voice-related absenteeism in teachers, 1,878 questionnaires were analysed. The questionnaires inquired about personal data, voice complaints, voice-related absenteeism from work and conditions that may lead to voice complaints

  2. Risk factors for voice problems in teachers.

    NARCIS (Netherlands)

    Kooijman, P.G.C.; Jong, F.I.C.R.S. de; Thomas, G.; Huinck, W.J.; Donders, A.R.T.; Graamans, K.; Schutte, H.K.

    2006-01-01

    In order to identify factors that are associated with voice problems and voice-related absenteeism in teachers, 1,878 questionnaires were analysed. The questionnaires inquired about personal data, voice complaints, voice-related absenteeism from work and conditions that may lead to voice complaints

  3. Keyboard With Voice Output

    Science.gov (United States)

    Huber, W. C.

    1986-01-01

    Voice synthesizer tells what key is about to be depressed. Verbal feedback useful for blind operators or where dim light prevents sighted operator from seeing keyboard. Also used where operator is busy observing other things while keying data into control system. Used as training aid for touch typing, and to train blind operators to use both standard and braille keyboards. Concept adapted to such equipment as typewriters, computers, calculators, telephones, cash registers, and on/off controls.

  4. Timelike Constant Mean Curvature Surfaces with Singularities

    DEFF Research Database (Denmark)

    Brander, David; Svensson, Martin

    2014-01-01

    We use integrable systems techniques to study the singularities of timelike non-minimal constant mean curvature (CMC) surfaces in the Lorentz–Minkowski 3-space. The singularities arise at the boundary of the Birkhoff big cell of the loop group involved. We examine the behavior of the surfaces at ...

  5. Timelike Constant Mean Curvature Surfaces with Singularities

    DEFF Research Database (Denmark)

    Brander, David; Svensson, Martin

    2014-01-01

    We use integrable systems techniques to study the singularities of timelike non-minimal constant mean curvature (CMC) surfaces in the Lorentz–Minkowski 3-space. The singularities arise at the boundary of the Birkhoff big cell of the loop group involved. We examine the behavior of the surfaces...

  6. Discrete variable representation for singular Hamiltonians

    DEFF Research Database (Denmark)

    Schneider, B. I.; Nygaard, Nicolai

    2004-01-01

    We discuss the application of the discrete variable representation (DVR) to Schrodinger problems which involve singular Hamiltonians. Unlike recent authors who invoke transformations to rid the eigenvalue equation of singularities at the cost of added complexity, we show that an approach based...

  7. On non-singular inhomogeneous cosmological models

    CERN Document Server

    Fernández-Jambrina, L

    2009-01-01

    In this talk we would like to review recent results on non-singular cosmological models. It has been recently shown that among stiff perfect fluid inhomogeneous spacetimes the absence of singularities is more common than it was expected in the literature. We would like to generalize these results and apply them to other matter sources.

  8. Singularities inside non-Abelian black holes

    OpenAIRE

    Gal'tsov, D. V.; Donets, E. E.; Zotov, M. Yu.

    1997-01-01

    Singularities inside static spherically symmetric black holes in the SU(2) Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theories are investigated. Analytical formulas are presented describing oscillatory and power law metric behavior near spacelike singularities in generic solutions.

  9. Twisting singular solutions of Bethe's equations

    CERN Document Server

    Nepomechie, Rafael I

    2014-01-01

    The Bethe equations for the periodic XXX and XXZ spin chains admit singular solutions, for which the corresponding eigenvalues and eigenvectors are ill-defined. We use a twist regularization to derive conditions for such singular solutions to be physical, in which case they correspond to genuine eigenvalues and eigenvectors of the Hamiltonian.

  10. The Geometry of Black Hole Singularities

    Directory of Open Access Journals (Sweden)

    Ovidiu Cristinel Stoica

    2014-01-01

    Full Text Available Recent results show that important singularities in General Relativity can be naturally described in terms of finite and invariant canonical geometric objects. Consequently, one can write field equations which are equivalent to Einstein's at nonsingular points but, in addition remain well-defined and smooth at singularities. The black hole singularities appear to be less undesirable than it was thought, especially after we remove the part of the singularity due to the coordinate system. Black hole singularities are then compatible with global hyperbolicity and do not make the evolution equations break down, when these are expressed in terms of the appropriate variables. The charged black holes turn out to have smooth potential and electromagnetic fields in the new atlas. Classical charged particles can be modeled, in General Relativity, as charged black hole solutions. Since black hole singularities are accompanied by dimensional reduction, this should affect Feynman's path integrals. Therefore, it is expected that singularities induce dimensional reduction effects in Quantum Gravity. These dimensional reduction effects are very similar to those postulated in some approaches to make Quantum Gravity perturbatively renormalizable. This may provide a way to test indirectly the effects of singularities, otherwise inaccessible.

  11. Quantum fields and "Big Rip" expansion singularities

    CERN Document Server

    Calderon, H; Calderon, Hector; Hiscock, William A.

    2005-01-01

    The effects of quantized conformally invariant massless fields on the evolution of cosmological models containing a ``Big Rip'' future expansion singularity are examined. Quantized scalar, spinor, and vector fields are found to strengthen the accelerating expansion of such models as they approach the expansion singularity.

  12. Reasons for singularity in robot teleoperation

    DEFF Research Database (Denmark)

    Marhenke, Ilka; Fischer, Kerstin; Savarimuthu, Thiusius Rajeeth

    2014-01-01

    In this paper, the causes for singularity of a robot arm in teleoperation for robot learning from demonstration are analyzed. Singularity is the alignment of robot joints, which prevents the configuration of the inverse kinematics. Inspired by users' own hypotheses, we investigated speed and delay...

  13. An extension theorem for conformal gauge singularities

    CERN Document Server

    Tod, Paul

    2007-01-01

    We analyse conformal gauge, or isotropic, singularities in cosmological models in general relativity. Using the calculus of tractors, we find conditions in terms of tractor curvature for a local extension of the conformal structure through a cosmological singularity and prove a local extension theorem.

  14. Correlation singularities in partially coherent electromagnetic beams

    NARCIS (Netherlands)

    Raghunathan, S.B.; Schouten, H.F.; Visser, T.D.

    2012-01-01

    We demonstrate that coherence vortices, singularities of the correlation function, generally occur in partially coherent electromagnetic beams. In successive cross sections of Gaussian Schell-model beams, their locus is found to be a closed string. These coherence singularities have implications for

  15. Resolving curvature singularities in holomorphic gravity

    NARCIS (Netherlands)

    Mantz, C.L.M.; Prokopec, T.

    2011-01-01

    We formulate a holomorphic theory of gravity and study how the holomorphy symmetry alters the two most important singular solutions of general relativity: black holes and cosmology. We show that typical observers (freely) falling into a holomorphic black hole do not encounter a curvature singularity

  16. Valley Singularities and Baryon Number Violation

    CERN Document Server

    Provero, P

    1994-01-01

    We consider the valley--method computation of the inclusive cross section of baryon number violating processes in the Standard Model. We show that any physically correct model of the valley action should present a singularity in the saddle point valley parameters as functions of the energy of the process. This singularity prevents the saddle point configuration from collapsing into the perturbative vacuum.

  17. Discrete singular convolution mapping methods for solving singular boundary value and boundary layer problems

    Science.gov (United States)

    Pindza, Edson; Maré, Eben

    2017-03-01

    A modified discrete singular convolution method is proposed. The method is based on the single (SE) and double (DE) exponential transformation to speed up the convergence of the existing methods. Numerical computations are performed on a wide variety of singular boundary value and singular perturbed problems in one and two dimensions. The obtained results from discrete singular convolution methods based on single and double exponential transformations are compared with each other, and with the existing methods too. Numerical results confirm that these methods are considerably efficient and accurate in solving singular and regular problems. Moreover, the method can be applied to a wide class of nonlinear partial differential equations.

  18. A singularity extraction technique for computation of antenna aperture fields from singular plane wave spectra

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Breinbjerg, Olav; Frandsen, Aksel

    2008-01-01

    An effective technique for extracting the singularity of plane wave spectra in the computation of antenna aperture fields is proposed. The singular spectrum is first factorized into a product of a finite function and a singular function. The finite function is inverse Fourier transformed...... numerically using the Inverse Fast Fourier Transform, while the singular function is inverse Fourier transformed analytically, using the Weyl-identity, and the two resulting spatial functions are then convolved to produce the antenna aperture field. This article formulates the theory of the singularity...

  19. Why Is My Voice Changing? (For Teens)

    Science.gov (United States)

    ... Week of Healthy Breakfasts Shyness Why Is My Voice Changing? KidsHealth > For Teens > Why Is My Voice ... deeper than a girl's, though. What Causes My Voice to Change? At puberty, guys' bodies begin producing ...

  20. Common Problems That Can Affect Your Voice

    Science.gov (United States)

    ... near you Common Problems That Can Affect Your Voice Common Problems That Can Affect Your Voice Patient ... that traditionally accompany gastro esophageal reflux disease (GERD). Voice Misuse and Overuse Speaking is a physical task ...

  1. Generalized Strong Curvature Singularities and Cosmic Censorship

    CERN Document Server

    Rudnicki, W; Kondracki, W

    2002-01-01

    A new definition of a strong curvature singularity is proposed. This definition is motivated by the definitions given by Tipler and Krolak, but is significantly different and more general. All causal geodesics terminating at these new singularities, which we call generalized strong curvature singularities, are classified into three possible types; the classification is based on certain relations between the curvature strength of the singularities and the causal structure in their neighborhood. A cosmic censorship theorem is formulated and proved which shows that only one class of generalized strong curvature singularities, corresponding to a single type of geodesics according to our classification, can be naked. Implications of this result for the cosmic censorship hypothesis are indicated.

  2. Singularities in gravitational collapse with radial pressure

    CERN Document Server

    Gonçalves, S M C V; Goncalves, Sergio M. C. V.; Jhingan, Sanjay

    2001-01-01

    We analyze spherical dust collapse with non-vanishing radial pressure, $\\Pi$, and vanishing tangential stresses. Considering a barotropic equation of state, $\\Pi=\\gamma\\rho$, we obtain an analytical solution in closed form---which is exact for $\\gamma=-1,0$, and approximate otherwise---near the center of symmetry (where the curvature singularity forms). We study the formation, visibility, and curvature strength of singularities in the resulting spacetime. We find that visible, Tipler strong singularities can develop from generic initial data. Radial pressure alters the spectrum of possible endstates for collapse, increasing the parameter space region that contains no visible singularities, but cannot by itself prevent the formation of visible singularities for sufficiently low values of the energy density. Known results from pressureless dust are recovered in the $\\gamma=0$ limit.

  3. Are loop quantum cosmos never singular?

    CERN Document Server

    Singh, Parampreet

    2009-01-01

    A unified treatment of all known types of singularities for flat, isotropic and homogeneous spacetimes in the framework of loop quantum cosmology (LQC) is presented. These include bangs, crunches and all future singularities. Using effective spacetime description we perform a model independent general analysis of the properties of curvature, behavior of geodesics and strength of singularities. For illustration purposes a phenomenological model based analysis is also performed. We show that all values of the scale factor at which a strong singularity may occur are excluded from the effective loop quantum spacetime. Further, if the evolution leads to either a vanishing or divergent scale factor then the loop quantum universe is asymptotically deSitter in that regime. We also show that there exist a class of sudden extremal events, which includes a recently discussed possibility, for which the curvature or its derivatives will always diverge. Such events however turn out to be harmless weak curvature singulariti...

  4. On non-singular GRADELA crack fields

    Directory of Open Access Journals (Sweden)

    Elias C. Aifantis

    2014-01-01

    Full Text Available A brief account is provided on crack-tip solutions that have recently been published in the literature by employing the so-called GRADELA model and its variants. The GRADELA model is a simple gradient elasticity theory involving one internal length in addition to the two Lame' constants, in an effort to eliminate elastic singularities and discontinuities and to interpret elastic size effects. The non-singular strains and non-singular (but sometimes singular or even hypersingular stresses derived this way under different boundary conditions differ from each other and their physical meaning in not clear. This is discussed which focus on the form and physical meaning of non-singular solutions for crack-tip stresses and strains that are possible to obtain within the GRADELA model and its extensions.

  5. Biclustering via Sparse Singular Value Decomposition

    KAUST Repository

    Lee, Mihee

    2010-02-16

    Sparse singular value decomposition (SSVD) is proposed as a new exploratory analysis tool for biclustering or identifying interpretable row-column associations within high-dimensional data matrices. SSVD seeks a low-rank, checkerboard structured matrix approximation to data matrices. The desired checkerboard structure is achieved by forcing both the left- and right-singular vectors to be sparse, that is, having many zero entries. By interpreting singular vectors as regression coefficient vectors for certain linear regressions, sparsity-inducing regularization penalties are imposed to the least squares regression to produce sparse singular vectors. An efficient iterative algorithm is proposed for computing the sparse singular vectors, along with some discussion of penalty parameter selection. A lung cancer microarray dataset and a food nutrition dataset are used to illustrate SSVD as a biclustering method. SSVD is also compared with some existing biclustering methods using simulated datasets. © 2010, The International Biometric Society.

  6. New Isotropic and Anisotropic Sudden Singularities

    CERN Document Server

    Barrow, J D; Barrow, John D.; Tsagas, Christos G.

    2004-01-01

    We show the existence of an infinite family of finite-time singularities in isotropically expanding universes which obey the weak, strong, and dominant energy conditions. We show what new type of energy condition is needed to exclude them ab initio. We also determine the conditions under which finite-time future singularities can arise in a wide class of anisotropic cosmological models. New types of finite-time singularity are possible which are characterised by divergences in the time-rate of change of the anisotropic-pressure tensor. We investigate the conditions for the formation of finite-time singularities in a Bianchi type $VII_{0}$ universe with anisotropic pressures and construct specific examples of anisotropic sudden singularities in these universes.

  7. Singularities in minimax optimization of networks

    DEFF Research Database (Denmark)

    Madsen, Kaj; Schjær-Jacobsen, Hans

    1976-01-01

    A theoretical treatment of singularities in nonlinear minimax optimization problems, which allows for a classification in regular and singular problems, is presented. A theorem for determining a singularity that is present in a given problem is formulated. A group of problems often used...... in the literature to test nonlinear minimax algorithms, i.e., minimax design of multisection quarter-wave transformers, is shown to exhibit singularities and the reason for this is pointed out. Based on the theoretical results presented an algorithm for nonlinear minimax optimization is developed. The new algorithm...... maintains the quadratic convergence property of a recent algorithm by Madsen et al. when applied to regular problems and it is demonstrated to significantly improve the final convergence on singular problems....

  8. $f(R,T)$ and future singularities

    CERN Document Server

    Mirza, Behrouz

    2014-01-01

    We investigate equations of motion and future singularities of $f(R,T)$ gravity where $R$ is the Ricci scalar and $T$ is the trace of stress-energy tensor. Future singularities for two kinds of equation of state (barotropic perfect fluid and generalized form of equation of state) are studied. While no future singularity is found for the first case, some kind of singularity is found to be possible for the second. Using the method of fixed points and certain assumptions, a large number of singularities can be removed. Finally, the effect of the Noether symmetry on $f(R,T)$ is studied and the consistent form of $f(R,T)$ function is found using the symmetry and the conserved charge.

  9. Voice and silence in organizations

    Directory of Open Access Journals (Sweden)

    Moaşa, H.

    2011-01-01

    Full Text Available Unlike previous research on voice and silence, this article breaksthe distance between the two and declines to treat them as opposites. Voice and silence are interrelated and intertwined strategic forms ofcommunication which presuppose each other in such a way that the absence of one would minimize completely the other’s presence. Social actors are not voice, or silence. Social actors can have voice or silence, they can do both because they operate at multiple levels and deal with multiple issues at different moments in time.

  10. VOICE REHABILITATION FOLLOWING TOTAL LARYNGECTOMY

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2015-03-01

    Full Text Available Despite continuing advances in surgical management of laryngeal malignancy, total laryngectomy is still the treatment of choice in advanced laryngeal malignancies. Considering the longevity of the patient following total laryngectomy, various measures have been adopted in order to provide voice function to the patient. Significant advancements have taken place in voice rehabilitation of post laryngectomy patients. Advancements in oncological surgical techniques and irradiation techniques have literally cured laryngeal malignancies. Among the various voice rehabilitation techniques available TEP (Tracheo oesophageal puncture is considered to be the gold standard. This article attempts to explore the various voice rehabilitation technique available with primary focus on TEP.

  11. The impact of voice on speech realization

    OpenAIRE

    Jelka Breznik

    2014-01-01

    The study discusses spoken literary language and the impact of voice on speech realization. The voice consists of a sound made by a human being using the vocal folds for talking, singing, laughing, crying, screaming… The human voice is specifically the part of human sound production in which the vocal folds (vocal cords) are the primary sound source. Our voice is our instrument and identity card. How does the voice (voice tone) affect others and how do they respond, positively or negatively? ...

  12. Singular solution of the Liouville equation under perturbation

    CERN Document Server

    Kalyakin, L A

    1999-01-01

    Small perturbation of the Liouville equation under singular initial data is considered. An asymptotics of the singular solution is constructed by the method which is similar to Bogolubov -- Krylov one. The main object is an asymptotics of the singular lines.

  13. Definition and classification of singularities in GR: classical and quantum

    CERN Document Server

    Konkowski, D A

    2004-01-01

    We will briefly review the definition and classification of classical and quantum singularities in general relativity. Examples of classically singular spacetimes that do not have quantum singularities will be given. We will present results on quantum singularities in quasiregular spacetimes. We will also show that a strong repulsive "potential" near the classical singularity can turn a classically singular spacetime into a quantum mechanically nonsingular spacetime.

  14. The Voice Handicap Index with Post-Laryngectomy Male Voices

    Science.gov (United States)

    Evans, Eryl; Carding, Paul; Drinnan, Michael

    2009-01-01

    Background: Surgical treatment for advanced laryngeal cancer involves complete removal of the larynx ("laryngectomy") and initial total loss of voice. Post-laryngectomy rehabilitation involves implementation of different means of "voicing" for these patients wherever possible. There is little information about laryngectomees'…

  15. Pedagogic Voice: Student Voice in Teaching and Engagement Pedagogies

    Science.gov (United States)

    Baroutsis, Aspa; McGregor, Glenda; Mills, Martin

    2016-01-01

    In this paper, we are concerned with the notion of "pedagogic voice" as it relates to the presence of student "voice" in teaching, learning and curriculum matters at an alternative, or second chance, school in Australia. This school draws upon many of the principles of democratic schooling via its utilisation of student voice…

  16. Numerical quadrature methods for integrals of singular periodic functions and their application to singular and weakly singular integral equations

    Science.gov (United States)

    Sidi, A.; Israeli, M.

    1986-01-01

    High accuracy numerical quadrature methods for integrals of singular periodic functions are proposed. These methods are based on the appropriate Euler-Maclaurin expansions of trapezoidal rule approximations and their extrapolations. They are used to obtain accurate quadrature methods for the solution of singular and weakly singular Fredholm integral equations. Such periodic equations are used in the solution of planar elliptic boundary value problems, elasticity, potential theory, conformal mapping, boundary element methods, free surface flows, etc. The use of the quadrature methods is demonstrated with numerical examples.

  17. The structure of the classical cosmological singularity

    Science.gov (United States)

    Tipler, Frank J.

    The existence of an all-encompassing initial classical cosmological singularity is established: it is shown that if: (1) global hyperbolicity, (2) the timelike convergence condition, and (3) all past-directed nonspacelike geodesics start to reconverge within a compact region in the causal past of the present-day earth, then all timelike curves in the past have a finite proper time length less than a universal constant L. It is argued that an analogue of this predicted cosmological singularity should exist even when quantum effects are taken into account. In particular, in a closed Friedmann radiation-filled universe quantized via the ADM method, the R = 0 singularity still exists and influences wave packet evolution at all times. Furthermore, quantum effects can in most cases eliminate curvature singularities only by introducing singularities in the universal action; most classical closed universes have finite action if and only if they begin and end in curvature singularities. Finally, the two basic ways of studying the structure of cosmological singularities are reviewed: completion methods (e.g., the c-boundary construction), and approach methods (e.g., analyzing metric behavior in a synchronous coordinate system).

  18. Spin Singularities: Clifford Kaleidoscopes and Particle Masses

    CERN Document Server

    Cohen, Marcus S

    2009-01-01

    Are particles singularities- vortex lines, tubes, or sheets in some global ocean of dark energy? We visit the zoo of Lagrangian singularities, or caustics in a spin(4,C) phase flow over compactifed Minkowsky space, and find that their varieties and energies parallel the families and masses of the elementary particles. Singularities are classified by tensor products of J Coxeter groups s generated by reflections. The multiplicity, s, is the number reflections needed to close a cycle of null zigzags: nonlinear resonances of J chiral pairs of lightlike matter spinors with (4-J) Clifford mirrors: dyads in the remaining unperturbed vacuum pairs. Using singular perturbations to "peel" phase-space singularities by orders in the vacuum intensity, we find that singular varieties with quantized mass, charge, and spin parallel the families of leptons (J=1), mesons (J=2), and hadrons (J=3). Taking the symplectic 4 form - the volume element in the 8- spinor phase space- as a natural Lagrangian, these singularities turn ou...

  19. Voice and Speech after Laryngectomy

    Science.gov (United States)

    Stajner-Katusic, Smiljka; Horga, Damir; Musura, Maja; Globlek, Dubravka

    2006-01-01

    The aim of the investigation is to compare voice and speech quality in alaryngeal patients using esophageal speech (ESOP, eight subjects), electroacoustical speech aid (EACA, six subjects) and tracheoesophageal voice prosthesis (TEVP, three subjects). The subjects reading a short story were recorded in the sound-proof booth and the speech samples…

  20. Voice Quality of Psychological Origin

    Science.gov (United States)

    Teixeira, Antonio; Nunes, Ana; Coimbra, Rosa Lidia; Lima, Rosa; Moutinho, Lurdes

    2008-01-01

    Variations in voice quality are essentially related to modifications of the glottal source parameters, such as: F[subscript 0], jitter, and shimmer. Voice quality is affected by prosody, emotional state, and vocal pathologies. Psychogenic vocal pathology is particularly interesting. In the present case study, the speaker naturally presented a…

  1. Voice handicap index in Swedish.

    Science.gov (United States)

    Ohlsson, Ann-Christine; Dotevall, Hans

    2009-01-01

    The objective of this study was to evaluate a Swedish version of the voice handicap index questionnaire (Sw-VHI). A total of 57 adult, dysphonic patients and 15 healthy controls completed the Sw-VHI and rated the degree of vocal fatigue and hoarseness on visual analogue scales. A perceptual voice evaluation was also performed. Test-retest reliability was analyzed in 38 subjects without voice complaints. Sw-VHI distinguished between dysphonic subjects and controls (P 0.84) and test-retest reliability (intraclass correlation coefficient >0.75) were good. Only moderate or weak correlations were found between Sw-VHI and the subjective and perceptual voice ratings. The data indicate that a difference above 13 points for the total Sw-VHI score and above 6 points for the Sw-VHI subscales is significant for an individual when comparing two different occasions. In conclusion, the Sw-VHI appears to be a robust instrument for assessment of the psycho-social impact of a voice disorder. However, Sw-VHI seems to, at least partly, capture different aspects of voice function to the subjective voice ratings and the perceptual voice evaluation.

  2. Enhancing Author's Voice through Scripting

    Science.gov (United States)

    Young, Chase J.; Rasinski, Timothy V.

    2011-01-01

    The authors suggest using scripting as a strategy to mentor and enhance author's voice in writing. Through gradual release, students use authentic literature as a model for writing with voice. The authors also propose possible extensions for independent practice, integration across content areas, and tips for evaluation.

  3. Voice, Schooling, Inequality, and Scale

    Science.gov (United States)

    Collins, James

    2013-01-01

    The rich studies in this collection show that the investigation of voice requires analysis of "recognition" across layered spatial-temporal and sociolinguistic scales. I argue that the concepts of voice, recognition, and scale provide insight into contemporary educational inequality and that their study benefits, in turn, from paying attention to…

  4. Voices in History

    Directory of Open Access Journals (Sweden)

    Ivan Leudar

    2001-06-01

    Full Text Available Experiences of “hearing voices” nowadays usually count as verbal hallucinations and they indicate serious mental illness. Some are first rank symptoms of schizophrenia, and the mass media, at least in Britain, tend to present them as antecedents of impulsive violence. They are, however, also found in other psychiatric conditions and epidemiological surveys reveal that even individuals with no need of psychiatric help can hear voices, sometimes following bereavement or abuse, but sometimes for no discernible reason. So do these experiences necessarily mean insanity and violence, and must they be thought of as pathogenic hallucinations; or are there other ways to understand them and live with them, and with what consequences?One way to make our thinking more flexible is to turn to history. We find that hearing voices was always an enigmatic experience, and the people who had it were rare. The gallery of voice hearers is, though, distinguished and it includes Galilei, Bunyan and St Teresa. Socrates heard a daemon who guided his actions, but in his time this did not signify madness, nor was it described as a hallucination. Yet in 19th century French psychological medicine the daemon became a hallucination and Socrates was retrospectively diagnosed as mentally ill. This paper examines the controversies which surrounded the experience at different points in history as well as the practice of retrospective psychiatry. The conclusion reached on the basis of the historical materials is that the experience and the ontological status it is ascribed are not trans-cultural or trans-historic but situated both in history and in the contemporary conflicts.

  5. Facing Sound - Voicing Art

    DEFF Research Database (Denmark)

    Lønstrup, Ansa

    2013-01-01

    This article is based on examples of contemporary audiovisual art, with a special focus on the Tony Oursler exhibition Face to Face at Aarhus Art Museum ARoS in Denmark in March-July 2012. My investigation involves a combination of qualitative interviews with visitors, observations of the audienc......´s interactions with the exhibition and the artwork in the museum space and short analyses of individual works of art based on reception aesthetics and phenomenology and inspired by newer writings on sound, voice and listening....

  6. Voice over IP Security

    CERN Document Server

    Keromytis, Angelos D

    2011-01-01

    Voice over IP (VoIP) and Internet Multimedia Subsystem technologies (IMS) are rapidly being adopted by consumers, enterprises, governments and militaries. These technologies offer higher flexibility and more features than traditional telephony (PSTN) infrastructures, as well as the potential for lower cost through equipment consolidation and, for the consumer market, new business models. However, VoIP systems also represent a higher complexity in terms of architecture, protocols and implementation, with a corresponding increase in the potential for misuse. In this book, the authors examine the

  7. Effects on vocal range and voice quality of singing voice training: the classically trained female voice.

    Science.gov (United States)

    Pabon, Peter; Stallinga, Rob; Södersten, Maria; Ternström, Sten

    2014-01-01

    A longitudinal study was performed on the acoustical effects of singing voice training under a given study program, using the voice range profile (VRP). Pretraining and posttraining recordings were made of students who participated in a 3-year bachelor singing study program. A questionnaire that included questions on optimal range, register use, classification, vocal health and hygiene, mixing technique, and training goals was used to rate and categorize self-assessed voice changes. Based on the responses, a subgroup of 10 classically trained female voices was selected, which was homogeneous enough for effects of training to be identified. The VRP perimeter contour was analyzed for effects of voice training. Also, a mapping within the VRP of voice quality, as expressed by the crest factor, was used to indicate the register boundaries and to monitor the acoustical consequences of the newly learned vocal technique of "mixed voice." VRPs were averaged across subjects. Findings were compared with the self-assessed vocal changes. Pre/post comparison of the average VRPs showed, in the midrange, (1) a decrease in the VRP area that was associated with the loud chest voice, (2) a reduction of the crest factor values, and (3) a reduction of maximum sound pressure level values. The students' self-evaluations of the voice changes appeared in some cases to contradict the VRP findings. VRPs of individual voices were seen to change over the course of a singing education. These changes were manifest also in the average group. High-resolution computerized recording, complemented with an acoustic register marker, allows a meaningful assessment of some effects of training, on an individual basis and for groups that comprise singers of a specific genre. It is argued that this kind of investigation is possible only within a focused training program, given by a faculty who has agreed on the goals. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  8. Potential singularity mechanism for the Euler equations

    Science.gov (United States)

    Brenner, Michael P.; Hormoz, Sahand; Pumir, Alain

    2016-12-01

    Singular solutions to the Euler equations could provide essential insight into the formation of very small scales in highly turbulent flows. Previous attempts to find singular flow structures have proven inconclusive. We reconsider the problem of interacting vortex tubes, for which it has long been observed that the flattening of the vortices inhibits sustained self-amplification of velocity gradients. Here we consider an iterative mechanism, based on the transformation of vortex filaments into sheets and their subsequent instability back into filaments. Elementary fluid mechanical arguments are provided to support the formation of a singular structure via this iterated mechanism, which we analyze based on a simplified model of filament interactions.

  9. Isotropic cosmological singularities other matter models

    CERN Document Server

    Tod, K P

    2003-01-01

    Isotropic cosmological singularities are singularities which can be removed by rescaling the metric. In some cases already studied (gr-qc/9903008, gr-qc/9903009, gr-qc/9903018) existence and uniqueness of cosmological models with data at the singularity has been established. These were cosmologies with, as source, either perfect fluids with linear equations of state or massless, collisionless particles. In this article we consider how to extend these results to a variety of other matter models. These are scalar fields, massive collisionless matter, the Yang-Mills plasma of Choquet-Bruhat, or matter satisfying the Einstein-Boltzmann equation.

  10. Non-singular circulant graphs and digraphs

    CERN Document Server

    Lal, A K

    2011-01-01

    We give necessary and sufficient conditions for a few classes of circulant graphs/digraphs to be singular. We also give two generalizations of the above graphs/digraphs, namely $(r,s,t)$-digraphs for non-negative integers $r,s$ and $t$, and the digraph $C_n^{i,j,k,l}$ with certain restrictions. A necessary and sufficient condition for the digraphs $C_n^{i,j,k,l}$ to be singular is obtained. Some necessary conditions are given under which the $(r,s,t)$-digraphs are singular.

  11. Quantum dress for a naked singularity

    Directory of Open Access Journals (Sweden)

    Marc Casals

    2016-09-01

    Full Text Available We investigate semiclassical backreaction on a conical naked singularity space–time with a negative cosmological constant in (2+1-dimensions. In particular, we calculate the renormalized quantum stress–energy tensor for a conformally coupled scalar field on such naked singularity space–time. We then obtain the backreacted metric via the semiclassical Einstein equations. We show that, in the regime where the semiclassical approximation can be trusted, backreaction dresses the naked singularity with an event horizon, thus enforcing (weak cosmic censorship.

  12. Singular Value Decomposition for Unitary Symmetric Matrix

    Institute of Scientific and Technical Information of China (English)

    ZOUHongxing; WANGDianjun; DAIQionghai; LIYanda

    2003-01-01

    A special architecture called unitary sym-metric matrix which embodies orthogonal, Givens, House-holder, permutation, and row (or column) symmetric ma-trices as its special cases, is proposed, and a precise corre-spondence of singular values and singular vectors between the unitary symmetric matrix and its mother matrix is de-rived. As an illustration of potential, it is shown that, for a class of unitary symmetric matrices, the singular value decomposition (SVD) using the mother matrix rather than the unitary symmetric matrix per se can save dramatically the CPU time and memory without loss of any numerical precision.

  13. Generalizations of the Abstract Boundary singularity theorem

    CERN Document Server

    Whale, Ben E; Scott, Susan M

    2015-01-01

    The Abstract Boundary singularity theorem was first proven by Ashley and Scott. It links the existence of incomplete causal geodesics in strongly causal, maximally extended spacetimes to the existence of Abstract Boundary essential singularities, i.e., non-removable singular boundary points. We give two generalizations of this theorem: the first to continuous causal curves and the distinguishing condition, the second to locally Lipschitz curves in manifolds such that no inextendible locally Lipschitz curve is totally imprisoned. To do this we extend generalized affine parameters from $C^1$ curves to locally Lipschitz curves.

  14. Questioning Photovoice Research: Whose Voice?

    Science.gov (United States)

    Evans-Agnew, Robin A; Rosemberg, Marie-Anne S

    2016-07-01

    Photovoice is an important participatory research tool for advancing health equity. Our purpose is to critically review how participant voice is promoted through the photovoice process of taking and discussing photos and adding text/captions. PubMed, Scopus, PsycINFO, and Web of Science databases were searched from the years 2008 to 2014 using the keywords photovoice, photonovella, photovoice and social justice, and photovoice and participatory action research. Research articles were reviewed for how participant voice was (a) analyzed, (b) exhibited in community forums, and (c) disseminated through published manuscripts. Of 21 studies, 13 described participant voice in the data analysis, 14 described participants' control over exhibiting photo-texts, seven manuscripts included a comprehensive set of photo-texts, and none described participant input on choice of manuscript photo-texts. Photovoice designs vary in the advancement of participant voice, with the least advancement occurring in manuscript publication. Future photovoice researchers should expand approaches to advancing participant voice.

  15. Voice quality of psychological origin.

    Science.gov (United States)

    Teixeira, Antonio; Nunes, Ana; Coimbra, Rosa Lídia; Lima, Rosa; Moutinho, Lurdes

    2008-01-01

    Variations in voice quality are essentially related to modifications of the glottal source parameters, such as: F0, jitter, and shimmer. Voice quality is affected by prosody, emotional state, and vocal pathologies. Psychogenic vocal pathology is particularly interesting. In the present case study, the speaker naturally presented a ventricular band voice whereas in a controlled production he was able to use a more normal phonation process. A small corpus was recorded which included sustained vowels and short sentences in both registers. A normal speaker was also recorded in similar tasks. Annotation and extraction of parameters were made using Praat's voice report function. Application of the Hoarseness Diagram to sustained productions situates this case in the pseudo-glottic phonation region. Analysis of several different parameters related to F0, jitter, shimmer, and harmonicity revealed that the speaker with psychogenic voice was capable of controlling certain parameters (e.g. F0 maximum) but was unable to correct others such as shimmer.

  16. Chemicals Industry Vision

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1996-12-01

    Chemical industry leaders articulated a long-term vision for the industry, its markets, and its technology in the groundbreaking 1996 document Technology Vision 2020 - The U.S. Chemical Industry. (PDF 310 KB).

  17. Home vision tests

    Science.gov (United States)

    ... the distance vision test above, but it is held only 14 inches (36 centimeters) away. If you ... Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  18. ON THE SINGULAR VARIATIONAL PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    谭经刚; 杨健夫

    2004-01-01

    The authors deal with the singular variational problem S(a,b,λ0):=infu∈E,u(≡/)0 ∫RN(||X|-a(△)u|m+∫|x|-(a+1)m|u|m)dx/(∫RN||X|-bU|P dx)m/p as well as (S)=(S)(a,b,λ1,λ2):=u,ν,E∈,u(u,ν)(≡/)(1,1) ∫RN J(u,ν)dx/(∫RN|x|-bp|u|α|ν|βdx)m/p, whereJ(u, v) = ||x|- au|m + λ1|x|- (a+1)m|u|m + ||x|- av|m + λ2|x|- (a+1)m|v|m,N ≥ m+ 1 > 2, 0 ≤ a < N-m/m, a ≤ b < a+ 1 and p = p(a,b) = α+β =Nm/N-m+m(b-a), α, β≥ 1, E = D1,mα(RN). The aim of this paper is to show the existence of minimizer for S(a, b, A0) and S(a, b, λ1, λ2).

  19. Conformal window and Landau singularities

    CERN Document Server

    Grunberg, G

    2001-01-01

    A physical characterization of Landau singularities is emphasized, which should trace the lower boundary N_f^* of the conformal window in QCD and supersymmetric QCD. A natural way to disentangle ``perturbative'' from ``non-perturbative'' contributions below N_f^* is suggested. Assuming an infrared fixed point is present in the perturbative part of the QCD coupling even in some range below N_f^* leads to the condition gamma(N_f^*)=1, where gamma is the critical exponent. Using the Banks-Zaks expansion, one gets 4

  20. Causal viscous cosmology without singularities

    CERN Document Server

    Laciana, Carlos E

    2016-01-01

    An isotropic and homogeneous cosmological model with a source of dark energy is studied. That source is simulated with a viscous relativistic fluid with minimal causal correction. In this model the restrictions on the parameters coming from the following conditions are analized: a) energy density without singularities along time, b) scale factor increasing with time, c) universe accelerated at present time, d) state equation for dark energy with "w" bounded and close to -1. It is found that those conditions are satified for the following two cases. i) When the transport coefficient ({\\tau}_{{\\Pi}}), associated to the causal correction, is negative, with the aditional restriction {\\zeta}|{\\tau}_{{\\Pi}}|>2/3, where {\\zeta} is the relativistic bulk viscosity coefficient. The state equation is in the "phantom" energy sector. ii) For {\\tau}_{{\\Pi}} positive, in the "k-essence" sector. It is performed an exact calculation for the case where the equation of state is constant, finding that option (ii) is favored in r...

  1. Muscular tension and body posture in relation to voice handicap and voice quality in teachers with persistent voice complaints.

    NARCIS (Netherlands)

    Kooijman, P.G.C.; Jong, F.I.C.R.S. de; Oudes, M.J.; Huinck, W.J.; Acht, H. van; Graamans, K.

    2005-01-01

    The aim of this study was to investigate the relationship between extrinsic laryngeal muscular hypertonicity and deviant body posture on the one hand and voice handicap and voice quality on the other hand in teachers with persistent voice complaints and a history of voice-related absenteeism. The st

  2. Robot Vision Library

    Science.gov (United States)

    Howard, Andrew B.; Ansar, Adnan I.; Litwin, Todd E.; Goldberg, Steven B.

    2009-01-01

    The JPL Robot Vision Library (JPLV) provides real-time robot vision algorithms for developers who are not vision specialists. The package includes algorithms for stereo ranging, visual odometry and unsurveyed camera calibration, and has unique support for very wideangle lenses

  3. Self-similar singular solution of doubly singular parabolic equation with gradient absorption term

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available We deal with the self-similar singular solution of doubly singular parabolic equation with a gradient absorption term u t = div ( | ∇ u m | p − 2 ∇ u m − | ∇ u | q for 1$"> p > 1 , 1$"> m ( p − 1 > 1 and 1$"> q > 1 in ℝ n × ( 0 , ∞ . By shooting and phase plane methods, we prove that when {1+n}/({1+mn}q+{mn}/({mn+1}$"> p > 1 + n / ( 1 + m n q + m n / ( m n + 1 there exists self-similar singular solution, while p ≤ n + 1 / ( 1 + m n q + m n / ( m n + 1 there is no any self-similar singular solution. In case of existence, the self-similar singular solution is the self-similar very singular solutions which have compact support. Moreover, the interface relation is obtained.

  4. Curvature singularities and abstract boundary singularity theorems for space-time

    CERN Document Server

    Ashley, M J S L; Ashley, Michael J. S. L.; Scott, Susan M.

    2003-01-01

    The abstract boundary construction of Scott and Szekeres is a general and flexible way to define singularities in General Relativity. The abstract boundary construction also proves of great utility when applied to questions about more general boundary features of space-time. Within this construction an essential singularity is a non-regular boundary point which is accessible by a curve of interest (e.g. a geodesic) within finite (affine) parameter distance and is not removable. Ashley and Scott proved the first theorem linking abstract boundary essential singularities with the notion of causal geodesic incompleteness for strongly causal, maximally extended space-times. The relationship between this result and the classical singularity theorems of Penrose and Hawking has enabled us to obtain abstract boundary singularity theorems. This paper describes essential singularity results for maximally extended space-times and presents our recent efforts to establish a relationship between the strong curvature singula...

  5. Bodies, Spaces, Voices, Silences

    Directory of Open Access Journals (Sweden)

    Donatella Mazzoleni

    2013-07-01

    Full Text Available A good architecture should not only allow functional, formal and technical quality for urban spaces, but also let the voice of the city be perceived, listened, enjoyed. Every city has got its specific sound identity, or “ISO” (R. O. Benenzon, made up of a complex texture of background noises and fluctuation of sound figures emerging and disappearing in a game of continuous fadings. For instance, the ISO of Naples is characterized by a spread need of hearing the sound return of one’s/others voices, by a hate of silence. Cities may fall ill: illness from noise, within super-crowded neighbourhoods, or illness from silence, in the forced isolation of peripheries. The proposal of an urban music therapy denotes an unpublished and innovative enlarged interdisciplinary research path, where architecture, music, medicine, psychology, communication science may converge, in order to work for rebalancing spaces and relation life of the urban collectivity, through the care of body and sound dimensions.

  6. Interaction Dynamics of Singular Wave Fronts

    CERN Document Server

    Holm, Darryl D

    2013-01-01

    Some of the most impressive singular wave fronts seen in Nature are the transbasin oceanic internal waves, which may be observed from the Space Shuttle as they propagate and interact with each other, for example, in the South China Sea. The characteristic feature of these strongly nonlinear wavefronts is that they reconnect when two of them collide transversely. We derive the EPDiff equation, and use it to model this phenomenon as elastic collisions between singular wave fronts (solitons) whose momentum is distributed along curves moving in the plane. Numerical methods for EPDiff based on compatible differencing algorithms (CDAs) are used for simulating these collisions among curves. The numerical results show the same nonlinear behavior of wavefront reconnections as that observed for internal waves in the South China Sea. We generalize the singular solutions of EPDiff for other applications, in computational anatomy and in imaging science, where the singular wavefronts are evolving image outlines, whose mome...

  7. Topological Signals of Singularities in Ricci Flow

    Directory of Open Access Journals (Sweden)

    Paul M. Alsing

    2017-08-01

    Full Text Available We implement methods from computational homology to obtain a topological signal of singularity formation in a selection of geometries evolved numerically by Ricci flow. Our approach, based on persistent homology, produces precise, quantitative measures describing the behavior of an entire collection of data across a discrete sample of times. We analyze the topological signals of geometric criticality obtained numerically from the application of persistent homology to models manifesting singularities under Ricci flow. The results we obtain for these numerical models suggest that the topological signals distinguish global singularity formation (collapse to a round point from local singularity formation (neckpinch. Finally, we discuss the interpretation and implication of these results and future applications.

  8. Dark matter annihilation near a naked singularity

    CERN Document Server

    Patil, Mandar

    2011-01-01

    We investigate here the dark matter annihilation near a Kerr naked singularity. We show that when dark matter particles collide and annihilate in vicinity of the singularity, the escape fraction to infinity of particles produced is much larger, at least 10^2 - 10^3 times the corresponding black hole values. As high energy collisions are generically possible near a naked singularity, this provides an excellent environment for efficient conversion of dark matter into ordinary standard model particles. If the center of galaxy harbored such a naked singularity, it follows that the observed emergent flux of particles with energy comparable to mass of the dark matter particles is much larger compared to the blackhole case, thus providing an intriguing observational test on the nature of the galactic center

  9. Resonance Van Hove Singularities in Wave Kinetics

    CERN Document Server

    Shi, Yi-Kang

    2015-01-01

    Wave kinetic theory has been developed to describe the statistical dynamics of weakly nonlinear, dispersive waves. However, we show that systems which are generally dispersive can have resonant sets of wave modes with identical group velocities, leading to a local breakdown of dispersivity. This shows up as a geometric singularity of the resonant manifold and possibly as an infinite phase measure in the collision integral. Such singularities occur widely for classical wave systems, including acoustical waves, Rossby waves, helical waves in rotating fluids, light waves in nonlinear optics and also in quantum transport, e.g. kinetics of electron-hole excitations (matter waves) in graphene. These singularities are the exact analogue of the critical points found by Van Hove in 1953 for phonon dispersion relations in crystals. The importance of these singularities in wave kinetics depends on the dimension of phase space $D=(N-2)d$ ($d$ physical space dimension, $N$ the number of waves in resonance) and the degree ...

  10. NEW RESULTS ON ESTIMATES FOR SINGULAR VALUES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    New results are provided to estimate matrix singular values in terms of partial absolute deleted row sums and column sums. Illustrative examples are presented to show comparisons with results in literature.

  11. Classically stable non-singular cosmological bounces

    CERN Document Server

    Ijjas, Anna

    2016-01-01

    One of the fundamental questions of theoretical cosmology is whether the universe can undergo a non-singular bounce, i.e., smoothly transit from a period of contraction to a period of expansion through violation of the null energy condition (NEC) at energies well below the Planck scale and at finite values of the scale factor such that the entire evolution remains classical. A common claim has been that a non-singular bounce either leads to ghost or gradient instabilities or a cosmological singularity. In this letter, we examine cubic Galileon theories and present a procedure for explicitly constructing examples of a non-singular cosmological bounce without encountering any pathologies and maintaining a sub-luminal sound speed for co-moving curvature modes throughout the NEC violating phase. We also discuss the relation between our procedure and earlier work.

  12. A reinterpretation of the Taub singularity

    OpenAIRE

    Jensen, Bjorn; Kučera, Jaromír

    1994-01-01

    We reinterpret the well known Taub-singularity in terms of a cylinder symmetric geometry. It is shown that a cylindrical analog to the Einstein-Rosen bridge as well as a cosmic string will be present in the geometry.

  13. Hybrid singular systems of differential equations

    Institute of Scientific and Technical Information of China (English)

    殷刚; 张纪峰

    2002-01-01

    This work develops hybrid models for large-scale singular differential system and analyzestheir asymptotic properties. To take into consideration the discrete shifts in regime across whichthe behavior of the corresponding dynamic systems is markedly different, our goals are to develophybrid systems in which continuous dynamics are intertwined with discrete events under random-jumpdisturbances and to reduce complexity of large-scale singular systems via singularly perturbed Markovchains. To reduce the complexity of large-scale hybrid singular systems, two-time scale is used in theformulation. Under general assumptions, limit behavior of the underlying system is examined. Usingweak convergence methods, it is shown that the systems can be approximated by limit systems inwhich the coefficients are averaged out with respect to the quasi-stationary distributions. Since thelimit systems have fewer states, the complexity is much reduced.

  14. Algunas aclaraciones acerca del conocimiento del singular.

    Directory of Open Access Journals (Sweden)

    Carlos Llano Cifuentes

    2013-11-01

    Full Text Available Llano tries to explain the main purpose of El Conocimiento del Singular, showing how the individuals about which the book is concerned are basically human individuals: people as decision makers.

  15. Tidal Forces in Naked Singularity Backgrounds

    CERN Document Server

    Goel, Akash; Roy, Pratim; Sarkar, Tapobrata

    2015-01-01

    The end stage of a gravitational collapse process can generically result in a black hole or a naked singularity. Here we undertake a comparative analysis of the nature of tidal forces in these backgrounds. The effect of such forces is generically exemplified by the Roche limit, which predicts the distance within which a celestial object disintegrates due to the tidal effects of a second more massive object. In this paper, using Fermi normal coordinates, we numerically compute the Roche limit for a class of non-rotating naked singularity backgrounds, and compare them with known results for Schwarzschild black holes. Our analysis indicates that there might be substantially large deviations in the magnitudes of tidal forces in naked singularity backgrounds, compared to the black hole cases. If observationally established, these can prove to be an effective indicator of the nature of the singularity at a galactic centre.

  16. Stable computation of generalized singular values

    Energy Technology Data Exchange (ETDEWEB)

    Drmac, Z.; Jessup, E.R. [Univ. of Colorado, Boulder, CO (United States)

    1996-12-31

    We study floating-point computation of the generalized singular value decomposition (GSVD) of a general matrix pair (A, B), where A and B are real matrices with the same numbers of columns. The GSVD is a powerful analytical and computational tool. For instance, the GSVD is an implicit way to solve the generalized symmetric eigenvalue problem Kx = {lambda}Mx, where K = A{sup {tau}}A and M = B{sup {tau}}B. Our goal is to develop stable numerical algorithms for the GSVD that are capable of computing the singular value approximations with the high relative accuracy that the perturbation theory says is possible. We assume that the singular values are well-determined by the data, i.e., that small relative perturbations {delta}A and {delta}B (pointwise rounding errors, for example) cause in each singular value {sigma} of (A, B) only a small relative perturbation {vert_bar}{delta}{sigma}{vert_bar}/{sigma}.

  17. Constraints on Singular Evolution from Gravitational Baryogenesis

    CERN Document Server

    Oikonomou, V K

    2015-01-01

    We investigate how the gravitational baryogenesis mechanism can potentially constrain the form of a Type IV singularity. Specifically, we study two different models with interesting phenomenology, that realize two distinct Type IV singularities, one occurring at the end of inflation and one during the radiation domination era or during the matter domination era. As we demonstrate, the Type IV singularities occurring at the matter domination era or during the radiation domination era, are constrained by the gravitational baryogenesis, in such a way so that these do not render the baryon to entropy ratio singular. Both the cosmological models we study cannot be realized in the context of ordinary Einstein-Hilbert gravity, and hence our work can only be realized in the context of $F(R)$ gravity and more generally in the context of modified gravity only.

  18. SINGULAR INTEGRAL EQUATIONS ALONG AN OPEN ARC WITH SOLUTIONS HAVING SINGULARITIES OF HIGHER ORDER

    Institute of Scientific and Technical Information of China (English)

    Zhong Shouguo

    2005-01-01

    In this paper, the difficulties on calculation in solving singular integral equations are overcome when the restriction of curve of integration to be a closed contour is cancelled. When the curve is an open arc and the solutions for singular integral equations possess singularities of higher order, the solution and the solvable condition for characteristic equations as well as the generalized Noether theorem for complete equations are given.

  19. Crossing Cultures with Multi-Voiced Journals

    Science.gov (United States)

    Styslinger, Mary E.; Whisenant, Alison

    2004-01-01

    In this article, the authors discuss the benefits of using multi-voiced journals as a teaching strategy in reading instruction. Multi-voiced journals, an adaptation of dual-voiced journals, encourage responses to reading in varied, cultured voices of characters. It is similar to reading journals in that they prod students to connect to the lives…

  20. Singularities in universes with negative cosmological constant

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, F.J.

    1976-10-01

    It is well known that many universes with negative cosmological constant contain singularities. We shall generalize this result by proving that all closed universes with negative cosmological constant are both future and past timelike geodesically incomplete if the strong energy condition holds. No global causality conditions or restrictions on the initial data are used in the proof. Furthermore, we shall show that all open universes with a Cauchy surface and a negative cosmological constant are singular if the strong energy condition holds. (AIP)

  1. Noncommutative Black Holes and the Singularity Problem

    Energy Technology Data Exchange (ETDEWEB)

    Bastos, C; Bertolami, O [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Dias, N C; Prata, J N, E-mail: cbastos@fisica.ist.utl.pt, E-mail: orfeu.bertolami@fc.up.pt, E-mail: ncdias@mail.telepac.pt, E-mail: joao.prata@mail.telepac.pt [Departamento de Matematica, Universidade Lusofona de Humanidades e Tecnologias, Avenida Campo Grande, 376, 1749-024 Lisboa (Portugal)

    2011-09-22

    A phase-space noncommutativity in the context of a Kantowski-Sachs cosmological model is considered to study the interior of a Schwarzschild black hole. Due to the divergence of the probability of finding the black hole at the singularity from a canonical noncommutativity, one considers a non-canonical noncommutativity. It is shown that this more involved type of noncommutativity removes the problem of the singularity in a Schwarzschild black hole.

  2. Dynamic Singularity Spectrum Distribution of Sea Clutter

    Science.gov (United States)

    Xiong, Gang; Yu, Wenxian; Zhang, Shuning

    2015-12-01

    The fractal and multifractal theory have provided new approaches for radar signal processing and target-detecting under the background of ocean. However, the related research mainly focuses on fractal dimension or multifractal spectrum (MFS) of sea clutter. In this paper, a new dynamic singularity analysis method of sea clutter using MFS distribution is developed, based on moving detrending analysis (DMA-MFSD). Theoretically, we introduce the time information by using cyclic auto-correlation of sea clutter. For transient correlation series, the instantaneous singularity spectrum based on multifractal detrending moving analysis (MF-DMA) algorithm is calculated, and the dynamic singularity spectrum distribution of sea clutter is acquired. In addition, we analyze the time-varying singularity exponent ranges and maximum position function in DMA-MFSD of sea clutter. For the real sea clutter data, we analyze the dynamic singularity spectrum distribution of real sea clutter in level III sea state, and conclude that the radar sea clutter has the non-stationary and time-varying scale characteristic and represents the time-varying singularity spectrum distribution based on the proposed DMA-MFSD method. The DMA-MFSD will also provide reference for nonlinear dynamics and multifractal signal processing.

  3. Observational constraints on cosmological future singularities

    Energy Technology Data Exchange (ETDEWEB)

    Beltran Jimenez, Jose [Aix Marseille Univ, Universite de Toulon CNRS, CPT, Marseille (France); Lazkoz, Ruth [Euskal Herriko Unibertsitatea, Fisika Teorikoaren eta Zientziaren Historia Saila, Zientzia eta Teknologia Fakultatea, Bilbao (Spain); Saez-Gomez, Diego [Faculdade de Ciencias da Universidade de Lisboa, Departamento de Fisica, Instituto de Astrofisica e Ciencias do Espaco, Lisbon (Portugal); Salzano, Vincenzo [University of Szczecin, Institute of Physics, Szczecin (Poland)

    2016-11-15

    In this work we consider a family of cosmological models featuring future singularities. This type of cosmological evolution is typical of dark energy models with an equation of state violating some of the standard energy conditions (e.g. the null energy condition). Such a kind of behavior, widely studied in the literature, may arise in cosmologies with phantom fields, theories of modified gravity or models with interacting dark matter/dark energy. We briefly review the physical consequences of these cosmological evolution regarding geodesic completeness and the divergence of tidal forces in order to emphasize under which circumstances the singularities in some cosmological quantities correspond to actual singular spacetimes. We then introduce several phenomenological parameterizations of the Hubble expansion rate to model different singularities existing in the literature and use SN Ia, BAO and H(z) data to constrain how far in the future the singularity needs to be (under some reasonable assumptions on the behavior of the Hubble factor). We show that, for our family of parameterizations, the lower bound for the singularity time cannot be smaller than about 1.2 times the age of the universe, what roughly speaking means ∝2.8 Gyrs from the present time. (orig.)

  4. A child's vision.

    Science.gov (United States)

    Nye, Christina

    2014-06-01

    Implementing standard vision screening techniques in the primary care practice is the most effective means to detect children with potential vision problems at an age when the vision loss may be treatable. A critical period of vision development occurs in the first few weeks of life; thus, it is imperative that serious problems are detected at this time. Although it is not possible to quantitate an infant's vision, evaluating ocular health appropriately can mean the difference between sight and blindness and, in the case of retinoblastoma, life or death.

  5. Computational approaches to vision

    Science.gov (United States)

    Barrow, H. G.; Tenenbaum, J. M.

    1986-01-01

    Vision is examined in terms of a computational process, and the competence, structure, and control of computer vision systems are analyzed. Theoretical and experimental data on the formation of a computer vision system are discussed. Consideration is given to early vision, the recovery of intrinsic surface characteristics, higher levels of interpretation, and system integration and control. A computational visual processing model is proposed and its architecture and operation are described. Examples of state-of-the-art vision systems, which include some of the levels of representation and processing mechanisms, are presented.

  6. Vision and multiple sclerosis.

    Science.gov (United States)

    Hickman, Simon J; Raoof, Naz; McLean, Rebecca J; Gottlob, Irene

    2014-01-01

    Multiple sclerosis can affect vision in many ways, including optic neuritis, chronic optic neuropathy, retrochiasmal visual field defects, higher order cortical processing, double vision, nystagmus and also by related ocular conditions such as uveitis. There are also side effects from recently introduced multiple sclerosis treatments that can affect vision. This review will discuss all these aspects and how they come together to cause visual symptoms. It will then focus on practical aspects of how to recognise when there is a vision problem in a multiple sclerosis patient and on what treatments are available to improve vision.

  7. Computational approaches to vision

    Science.gov (United States)

    Barrow, H. G.; Tenenbaum, J. M.

    1986-01-01

    Vision is examined in terms of a computational process, and the competence, structure, and control of computer vision systems are analyzed. Theoretical and experimental data on the formation of a computer vision system are discussed. Consideration is given to early vision, the recovery of intrinsic surface characteristics, higher levels of interpretation, and system integration and control. A computational visual processing model is proposed and its architecture and operation are described. Examples of state-of-the-art vision systems, which include some of the levels of representation and processing mechanisms, are presented.

  8. Lexical frequency and voice assimilation.

    Science.gov (United States)

    Ernestus, Mirjam; Lahey, Mybeth; Verhees, Femke; Baayen, R Harald

    2006-08-01

    Acoustic duration and degree of vowel reduction are known to correlate with a word's frequency of occurrence. The present study broadens the research on the role of frequency in speech production to voice assimilation. The test case was regressive voice assimilation in Dutch. Clusters from a corpus of read speech were more often perceived as unassimilated in lower-frequency words and as either completely voiced (regressive assimilation) or, unexpectedly, as completely voiceless (progressive assimilation) in higher-frequency words. Frequency did not predict the voice classifications over and above important acoustic cues to voicing, suggesting that the frequency effects on the classifications were carried exclusively by the acoustic signal. The duration of the cluster and the period of glottal vibration during the cluster decreased while the duration of the release noises increased with frequency. This indicates that speakers reduce articulatory effort for higher-frequency words, with some acoustic cues signaling more voicing and others less voicing. A higher frequency leads not only to acoustic reduction but also to more assimilation.

  9. Hitchin Equation, Irregular Singularity, and $N=2$ Asymptotical Free Theories

    CERN Document Server

    Nanopoulos, Dimitri

    2010-01-01

    In this paper, we study irregular singular solution to Hitchin's equation and use it to describe four dimensional $N=2$ asymptotically free gauge theories. For $SU(2)$ $A$ type quiver, two kinds of irregular singularities besides one regular singularity are needed for the solution of Hitchin's equation; We then classify irregular singularities needed for the general $SU(N)$ $A$ type quiver.

  10. Minimal solution of singular LR fuzzy linear systems.

    Science.gov (United States)

    Nikuie, M; Ahmad, M Z

    2014-01-01

    In this paper, the singular LR fuzzy linear system is introduced. Such systems are divided into two parts: singular consistent LR fuzzy linear systems and singular inconsistent LR fuzzy linear systems. The capability of the generalized inverses such as Drazin inverse, pseudoinverse, and {1}-inverse in finding minimal solution of singular consistent LR fuzzy linear systems is investigated.

  11. Design of switched controllers for discrete singular bilinear systems

    Institute of Scientific and Technical Information of China (English)

    Xiuhua ZHANG; Qingling ZHANG

    2007-01-01

    In this paper, switched controllers are designed for a class of nonlinear discrete singular systems and a class of discrete singular bilinear systems. An invariant principle is presented for such switched nonlinear singular systems.The invariant principle and the switched controllers are used to globally stabilize a class of singular bilinear systems that are not open-loop stable.

  12. What is a Singularity in Geometrized Newtonian Gravitation?

    CERN Document Server

    Weatherall, James Owen

    2013-01-01

    I discuss singular spacetimes in the context of the geometrized formulation of Newtonian gravitation. I argue first that geodesic incompleteness is a natural criterion for when a model of geometrized Newtonian gravitation is singular, and then I show that singularities in this sense arise naturally in classical physics by stating and proving a classical version of the Raychaudhuri-Komar singularity theorem.

  13. Acquired color vision deficiency.

    Science.gov (United States)

    Simunovic, Matthew P

    2016-01-01

    Acquired color vision deficiency occurs as the result of ocular, neurologic, or systemic disease. A wide array of conditions may affect color vision, ranging from diseases of the ocular media through to pathology of the visual cortex. Traditionally, acquired color vision deficiency is considered a separate entity from congenital color vision deficiency, although emerging clinical and molecular genetic data would suggest a degree of overlap. We review the pathophysiology of acquired color vision deficiency, the data on its prevalence, theories for the preponderance of acquired S-mechanism (or tritan) deficiency, and discuss tests of color vision. We also briefly review the types of color vision deficiencies encountered in ocular disease, with an emphasis placed on larger or more detailed clinical investigations.

  14. Voice Habits and Behaviors: Voice Care Among Flamenco Singers.

    Science.gov (United States)

    Garzón García, Marina; Muñoz López, Juana; Y Mendoza Lara, Elvira

    2017-03-01

    The purpose of this study is to analyze the vocal behavior of flamenco singers, as compared with classical music singers, to establish a differential vocal profile of voice habits and behaviors in flamenco music. Bibliographic review was conducted, and the Singer's Vocal Habits Questionnaire, an experimental tool designed by the authors to gather data regarding hygiene behavior, drinking and smoking habits, type of practice, voice care, and symptomatology perceived in both the singing and the speaking voice, was administered. We interviewed 94 singers, divided into two groups: the flamenco experimental group (FEG, n = 48) and the classical control group (CCG, n = 46). Frequency analysis, a Likert scale, and discriminant and exploratory factor analysis were used to obtain a differential profile for each group. The FEG scored higher than the CCG in speaking voice symptomatology. The FEG scored significantly higher than the CCG in use of "inadequate vocal technique" when singing. Regarding voice habits, the FEG scored higher in "lack of practice and warm-up" and "environmental habits." A total of 92.6% of the subjects classified themselves correctly in each group. The Singer's Vocal Habits Questionnaire has proven effective in differentiating flamenco and classical singers. Flamenco singers are exposed to numerous vocal risk factors that make them more prone to vocal fatigue, mucosa dehydration, phonotrauma, and muscle stiffness than classical singers. Further research is needed in voice training in flamenco music, as a means to strengthen the voice and enable it to meet the requirements of this musical genre. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Voices of the Unheard

    DEFF Research Database (Denmark)

    Matthiesen, Noomi Christine Linde

    2014-01-01

    . They were in two different classes at both schools, i.e. four classes in total. The families were followed for 18 months. Formal interviews were conducted with mothers and teachers, parent-teacher conferences were recorded, participant observations were conducted in classrooms and playgrounds, afterschool...... is that Somali diaspora parents (and with special focus on mothers as these where the parents who took most responsibility in the four cases of this research) have difficulty expressing their opinions as there are structural, historical and social dynamics that create conditions in which their voices...... are silenced, or at least restricted significantly, resulting in marginalizing consequences. The focus in each article is on here-and-now interactional dynamics but in order to understand these constitutive negotiations, it is argued that the analysis must be situated in a description of the constituted...

  16. Passing on power & voice

    DEFF Research Database (Denmark)

    Noer, Vibeke Røn; Nielsen, Cathrine Sand

    2014-01-01

    . The education lasts for 3,5 years and the landmark of the educational model is the continuously shifts between teaching in classroom and teaching in clinical practice. Clinical teaching takes place at approved clinical placement institutions in hospitals and in the social and health care services outside...... intention of gaining knowledge about other possible ways to perform the education. The class, named the E-class, followed what in the field was named ‘an experimental educational model based on experienced-based learning’ (Nielsen et al. 2011). The experiential educational model is argued as an experiment.......aspx Higher degree of student involvement in planning as well as teaching was in the field presented as a part of ‘the overall educational approach’. In the course ‘Acute, Critical Nursing & Terminal, Palliative Care’ this was transferred into an innovative pedagogy with intend to pass on power and voice...

  17. Voice stress analysis

    Science.gov (United States)

    Brenner, Malcolm; Shipp, Thomas

    1988-01-01

    In a study of the validity of eight candidate voice measures (fundamental frequency, amplitude, speech rate, frequency jitter, amplitude shimmer, Psychological Stress Evaluator scores, energy distribution, and the derived measure of the above measures) for determining psychological stress, 17 males age 21 to 35 were subjected to a tracking task on a microcomputer CRT while parameters of vocal production as well as heart rate were measured. Findings confirm those of earlier studies that increases in fundamental frequency, amplitude, and speech rate are found in speakers involved in extreme levels of stress. In addition, it was found that the same changes appear to occur in a regular fashion within a more subtle level of stress that may be characteristic, for example, of routine flying situations. None of the individual speech measures performed as robustly as did heart rate.

  18. Voice over IP

    OpenAIRE

    Mantula, Juha

    2006-01-01

    Tämä opinnäytetyö käsittelee Voice over Internet Protocol -tekniikkaa ja sen tuomia mahdollisuuksia yrityselämässä. Teoriaosa käsittelee VoIP:n kannalta tärkeitä pro-tokollia ja standardeja, VoIP:n ominaisuuksia sekä esittelee erilaisia puheohjelmia, jotka käyttävät VoIP-tekniikkaa hyväkseen. Empiirinen osuus tutkii Viestintä Ky Pitkärannan Skype-ohjelman käyttöä. Työn tarkoituksena on selvittää VoIP:n hyviä ja huonoja puolia ja sitä kuinka tek-niikkaa voidaan käyttää hyväksi päivittäisessä ...

  19. Resonance Van Hove singularities in wave kinetics

    Science.gov (United States)

    Shi, Yi-Kang; Eyink, Gregory L.

    2016-10-01

    Wave kinetic theory has been developed to describe the statistical dynamics of weakly nonlinear, dispersive waves. However, we show that systems which are generally dispersive can have resonant sets of wave modes with identical group velocities, leading to a local breakdown of dispersivity. This shows up as a geometric singularity of the resonant manifold and possibly as an infinite phase measure in the collision integral. Such singularities occur widely for classical wave systems, including acoustical waves, Rossby waves, helical waves in rotating fluids, light waves in nonlinear optics and also in quantum transport, e.g. kinetics of electron-hole excitations (matter waves) in graphene. These singularities are the exact analogue of the critical points found by Van Hove in 1953 for phonon dispersion relations in crystals. The importance of these singularities in wave kinetics depends on the dimension of phase space D =(N - 2) d (d physical space dimension, N the number of waves in resonance) and the degree of degeneracy δ of the critical points. Following Van Hove, we show that non-degenerate singularities lead to finite phase measures for D > 2 but produce divergences when D ≤ 2 and possible breakdown of wave kinetics if the collision integral itself becomes too large (or even infinite). Similar divergences and possible breakdown can occur for degenerate singularities, when D - δ ≤ 2, as we find for several physical examples, including electron-hole kinetics in graphene. When the standard kinetic equation breaks down, then one must develop a new singular wave kinetics. We discuss approaches from pioneering 1971 work of Newell & Aucoin on multi-scale perturbation theory for acoustic waves and field-theoretic methods based on exact Schwinger-Dyson integral equations for the wave dynamics.

  20. Reiteration of Hankel singular value decomposition for modeling of complex-valued signal

    Science.gov (United States)

    Staniszewski, Michał; Skorupa, Agnieszka; Boguszewicz, Łukasz; Wicher, Magdalena; Konopka, Marek; Sokół, Maria; Polański, Andrzej

    2016-06-01

    Modeling signal which forms complex values is a common scientific problem, which is present in many applications, i.e. in medical signals, computer graphics and vision. One of the possible solution is utilization of Hankel Singular Value Decomposition. In the first step complex-valued signal is arranged in a special form called Hankel matrix, which is in the next step decomposed in operation of Singular Value Decomposition. Obtained matrices can be then reformulated in order to get parameters describing system. Basic method can be applied for fitting whole signal but it fails in modeling each particular component of signal. Modification of basic HSVD method, which relies on reiteration and is used for main components, and application of prior knowledge solves presented problem.

  1. Voice and choice by delegation.

    Science.gov (United States)

    van de Bovenkamp, Hester; Vollaard, Hans; Trappenburg, Margo; Grit, Kor

    2013-02-01

    In many Western countries, options for citizens to influence public services are increased to improve the quality of services and democratize decision making. Possibilities to influence are often cast into Albert Hirschman's taxonomy of exit (choice), voice, and loyalty. In this article we identify delegation as an important addition to this framework. Delegation gives individuals the chance to practice exit/choice or voice without all the hard work that is usually involved in these options. Empirical research shows that not many people use their individual options of exit and voice, which could lead to inequality between users and nonusers. We identify delegation as a possible solution to this problem, using Dutch health care as a case study to explore this option. Notwithstanding various advantages, we show that voice and choice by delegation also entail problems of inequality and representativeness.

  2. The Christian voice in philosophy

    Directory of Open Access Journals (Sweden)

    Stuart Fowler

    1982-03-01

    Full Text Available In this paper the Rev. Stuart Fowler outlines a Christian voice in Philosophy and urges the Christian philosopher to investigate his position and his stance with integrity and honesty.

  3. Voice Force tulekul / Tõnu Ojala

    Index Scriptorium Estoniae

    Ojala, Tõnu, 1969-

    2005-01-01

    60. sünnipäeva tähistava Tallinna Tehnikaülikooli Akadeemilise Meeskoori juubelihooaja üritusest - a capella pop-gruppide festivalist Voice Force (kontserdid 12. nov. klubis Parlament ja 3. dets. Vene Kultuurikeskuses)

  4. Voice Force tulekul / Tõnu Ojala

    Index Scriptorium Estoniae

    Ojala, Tõnu, 1969-

    2005-01-01

    60. sünnipäeva tähistava Tallinna Tehnikaülikooli Akadeemilise Meeskoori juubelihooaja üritusest - a capella pop-gruppide festivalist Voice Force (kontserdid 12. nov. klubis Parlament ja 3. dets. Vene Kultuurikeskuses)

  5. Singular Integral Equations with Cosecant Kernel in Solutions with Singularities of High Order

    Institute of Scientific and Technical Information of China (English)

    HAN Hui-li; DU Jin-yuan

    2005-01-01

    We have discussed and solved the boundary value problem with period 2aπ and the singular integral equation with kernel csc t-t0/a in solution having singularities of high order, where the smooth contour of integration is in the strip 0<Rez<aπ.

  6. ON THE BOREL SUMMABILITY OF FORMAL SOLUTIONS FOR SOME FIRST ORDER SINGULAR PDES WITH IRREGULAR SINGULARITY

    Institute of Scientific and Technical Information of China (English)

    Chen Hua; Zhang Zhixiong

    2005-01-01

    In this paper the authors consider the summability of formal solutions for some first order singular PDEs with irregular singularity. They prove that in this case the formal solutions will be divergent, but except a enumerable directions, the formal solutions are Borel summable.

  7. Feature Extraction of Voice Segments Using Cepstral Analysis for Voice Regeneration

    OpenAIRE

    Banerjee, P. S.; Baisakhi Chakraborty; Jaya Banerjee

    2015-01-01

    Even though a lot of work has been done on areas of speech to text and vice versa or voice detection or similarity analysis of two voice samples but very less emphasis has be given to voice regeneration. General algorithms for distinct voice checking for two voice sources paved way for our endeavor in reconstructing the voice from the source voice samples provided. By utilizing these algorithms and putting further stress on the feature extraction part we tried to fabricate the source voice wi...

  8. Voice Simulation in Nursing Education.

    Science.gov (United States)

    Kepler, Britney B; Lee, Heeyoung; Kane, Irene; Mitchell, Ann M

    2016-01-01

    The goal of this study was to improve prelicensure nursing students' attitudes toward and self-efficacy related to delivering nursing care to patients with auditory hallucinations. Based on the Hearing Voices That Are Distressing curriculum, 87 participants were instructed to complete 3 tasks while wearing headphones delivering distressing voices. Comparing presimulation and postsimulation results, this study suggests that the simulation significantly improved attitudes toward patients with auditory hallucinations; however, self-efficacy related to caring for these patients remained largely unchanged.

  9. Work-related voice disorder

    OpenAIRE

    Paulo Eduardo Przysiezny; Luciana Tironi Sanson Przysiezny

    2015-01-01

    INTRODUCTION: Dysphonia is the main symptom of the disorders of oral communication. However, voice disorders also present with other symptoms such as difficulty in maintaining the voice (asthenia), vocal fatigue, variation in habitual vocal fundamental frequency, hoarseness, lack of vocal volume and projection, loss of vocal efficiency, and weakness when speaking. There are several proposals for the etiologic classification of dysphonia: functional, organofunctional, organic, and work-related...

  10. Tracheostomy cannulas and voice prosthesis.

    Science.gov (United States)

    Kramp, Burkhard; Dommerich, Steffen

    2009-01-01

    Cannulas and voice prostheses are mechanical aids for patients who had to undergo tracheotomy or laryngectomy for different reasons. For better understanding of the function of those artificial devices, first the indications and particularities of the previous surgical intervention are described in the context of this review. Despite the established procedure of percutaneous dilatation tracheotomy e.g. in intensive care units, the application of epithelised tracheostomas has its own position, especially when airway obstruction is persistent (e.g. caused by traumata, inflammations, or tumors) and a longer artificial ventilation or special care of the patient are required. In order to keep the airways open after tracheotomy, tracheostomy cannulas of different materials with different functions are available. For each patient the most appropriate type of cannula must be found. Voice prostheses are meanwhile the device of choice for rapid and efficient voice rehabilitation after laryngectomy. Individual sizes and materials allow adaptation of the voice prostheses to the individual anatomical situation of the patients. The combined application of voice prostheses with HME (Head and Moisture Exchanger) allows a good vocal as well as pulmonary rehabilitation. Precondition for efficient voice prosthesis is the observation of certain surgical principles during laryngectomy. The duration of the prosthesis mainly depends on material properties and biofilms, mostly consisting of funguses and bacteries. The quality of voice with valve prosthesis is clearly superior to esophagus prosthesis or electro-laryngeal voice. Whenever possible, tracheostoma valves for free-hand speech should be applied. Physicians taking care of patients with speech prostheses after laryngectomy should know exactly what to do in case the device fails or gets lost.

  11. Voice Collection under Different Spectrum

    Directory of Open Access Journals (Sweden)

    Min Li

    2013-05-01

    Full Text Available According to the short-time Fourier transform theory and principle of digital filtering, this paper established a mathematical model called collection of voice signal collection at different spectrum. The voice signal was a non-stationary process, while the standard Fourier transform only applied to the periodic signal, transient signals or stationary random signal. Therefore, the standard Fourier transform could not be directly used for the speech signal. By controlling the input different types and parameters, this paper analyzed the collected original voice signal spectrum with the use of MATLAB software platform. At the same time, it realized the extraction, recording and playback of the speech signal at different frequencies. Therefore, the waveforms could be displayed obviously on the graphic user interface and voice effect could be more clearly. Meanwhile, the result was verified by the hardware platforms, which consisted of TMS320VC5509A [1] chip and TLV320AIC23 voice chip. The results showed that the extraction of voice signal under different spectrum model was scientific, rational and effective.

  12. Singular Value Decomposition of Pinhole SPECT Systems.

    Science.gov (United States)

    Palit, Robin; Kupinski, Matthew A; Barrett, Harrison H; Clarkson, Eric W; Aarsvold, John N; Volokh, Lana; Grobshtein, Yariv

    2009-03-12

    A single photon emission computed tomography (SPECT) imaging system can be modeled by a linear operator H that maps from object space to detector pixels in image space. The singular vectors and singular-value spectra of H provide useful tools for assessing system performance. The number of voxels used to discretize object space and the number of collection angles and pixels used to measure image space make the matrix dimensions H large. As a result, H must be stored sparsely which renders several conventional singular value decomposition (SVD) methods impractical. We used an iterative power methods SVD algorithm (Lanczos) designed to operate on very large sparsely stored matrices to calculate the singular vectors and singular-value spectra for two small animal pinhole SPECT imaging systems: FastSPECT II and M(3)R. The FastSPECT II system consisted of two rings of eight scintillation cameras each. The resulting dimensions of H were 68921 voxels by 97344 detector pixels. The M(3)R system is a four camera system that was reconfigured to measure image space using a single scintillation camera. The resulting dimensions of H were 50864 voxels by 6241 detector pixels. In this paper we present results of the SVD of each system and discuss calculation of the measurement and null space for each system.

  13. Quantum cosmology and late-time singularities

    CERN Document Server

    Kamenshchik, A Yu

    2013-01-01

    The development of dark energy models has stimulated interest to cosmological singularities, which differ from the traditional Big Bang and Big Crunch singularities. We review a broad class of phenomena connected with soft cosmological singularities in classical and quantum cosmology. We discuss the classification of singularities from the geometrical point of view and from the point of view of the behaviour of finite size objects, crossing such singularities. We discuss in some detail quantum and classical cosmology of models based on perfect fluids (anti-Chaplygin gas and anti-Chaplygin gas plus dust), of models based on the Born-Infeld-type fields and of the model of a scalar field with a potential inversely proportional to the field itself. We dwell also on the phenomenon of the phantom divide line crossing in the scalar field models with cusped potentials. Then we discuss the Friedmann equations modified by quantum corrections to the effective action of the models under considerations and the influence o...

  14. The impact of voice on speech realization

    Directory of Open Access Journals (Sweden)

    Jelka Breznik

    2014-12-01

    Full Text Available The study discusses spoken literary language and the impact of voice on speech realization. The voice consists of a sound made by a human being using the vocal folds for talking, singing, laughing, crying, screaming… The human voice is specifically the part of human sound production in which the vocal folds (vocal cords are the primary sound source. Our voice is our instrument and identity card. How does the voice (voice tone affect others and how do they respond, positively or negatively? How important is voice (voice tone in communication process? The study presents how certain individuals perceive voice. The results of the research on the relationships between the spoken word, excellent speaker, voice and description / definition / identification of specific voices done by experts in the field of speech and voice as well as non-professionals are presented. The study encompasses two focus groups. One consists of amateurs (non-specialists in the field of speech or voice who have no knowledge in this field and the other consists of professionals who work with speech or language or voice. The questions were intensified from general to specific, directly related to the topic. The purpose of such a method of questioning was to create relaxed atmosphere, promote discussion, allow participants to interact, complement, and to set up self-listening and additional comments.

  15. Mathematical leadership vision.

    Science.gov (United States)

    Hamburger, Y A

    2000-11-01

    This article is an analysis of a new type of leadership vision, the kind of vision that is becoming increasingly pervasive among leaders in the modern world. This vision appears to offer a new horizon, whereas, in fact it delivers to its target audience a finely tuned version of the already existing ambitions and aspirations of the target audience. The leader, with advisors, has examined the target audience and has used the results of extensive research and statistical methods concerning the group to form a picture of its members' lifestyles and values. On the basis of this information, the leader has built a "vision." The vision is intended to create an impression of a charismatic and transformational leader when, in fact, it is merely a response. The systemic, arithmetic, and statistical methods employed in this operation have led to the coining of the terms mathematical leader and mathematical vision.

  16. FPGA Vision Data Architecture

    Science.gov (United States)

    Morfopoulos, Arin C.; Pham, Thang D.

    2013-01-01

    JPL has produced a series of FPGA (field programmable gate array) vision algorithms that were written with custom interfaces to get data in and out of each vision module. Each module has unique requirements on the data interface, and further vision modules are continually being developed, each with their own custom interfaces. Each memory module had also been designed for direct access to memory or to another memory module.

  17. Measuring Vision in Children

    Directory of Open Access Journals (Sweden)

    Petra Verweyen

    2004-01-01

    Full Text Available Measuring vision in children is a special skill requiring time, patience and understanding. Methods should be adapted to the child’s age, abilities, knowledge and experience. Young children are not able to describe their vision or explain their visual symptoms. Through observation, and with information from the mother or guardian, functional vision can be evaluated. While testing and observing children, an experienced assessor notices their responses to visual stimuli. These must be compared with the expected functional vision for children of the same age and abilities, so it is important to know the normal visual development.

  18. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  19. Artificial human vision.

    Science.gov (United States)

    Dowling, Jason

    2005-01-01

    Can vision be restored to the blind? As early as 1929 it was discovered that stimulating the visual cortex of an individual led to the perception of spots of light, known as phosphenes [1] . The aim of artificial human vision systems is to attempt to utilize the perception of phosphenes to provide a useful substitute for normal vision. Currently, four locations for electrical stimulation are being investigated; behind the retina (subretinal), in front of the retina (epiretinal), the optic nerve and the visual cortex (using intra- and surface electrodes). This review discusses artificial human vision technology and requirements, and reviews the current development projects.

  20. Singularity hypotheses a scientific and philosophical assessment

    CERN Document Server

    Moor, James; Søraker, Johnny; Steinhart, Eric

    2012-01-01

    Singularity Hypotheses: A Scientific and Philosophical Assessment offers authoritative, jargon-free essays and critical commentaries on accelerating technological progress and the notion of technological singularity. It focuses on conjectures about the intelligence explosion, transhumanism, and whole brain emulation. Recent years have seen a plethora of forecasts about the profound, disruptive impact that is likely to result from further progress in these areas. Many commentators however doubt the scientific rigor of these forecasts, rejecting them as speculative and unfounded. We therefore invited prominent computer scientists, physicists, philosophers, biologists, economists and other thinkers to assess the singularity hypotheses. Their contributions go beyond speculation, providing deep insights into the main issues and a balanced picture of the debate.

  1. Naked Singularities as Particle Accelerators II

    CERN Document Server

    Patil, Mandar; Malafarina, Daniele

    2011-01-01

    We generalize here our earlier results on particle acceleration by naked singularities. We showed recently[1] that the naked singularities that form due to gravitational collapse of massive stars provide a suitable environment where particles could get accelerated and collide at arbitrarily high center of mass energies. However, we focussed there only on the spherically symmetric gravitational collapse models, which were also assumed to be self-similar. In this paper, we broaden and generalize the result to all gravitational collapse models leading to the formation of a naked singularity as final state of collapse, evolving from a regular initial data, without making any prior restrictive assumptions about the spacetime symmetries such as above. We show that when the particles interact and collide near the Cauchy horizon, the energy of collision in the center of mass frame will be arbitrarily high, thus offering a window to the Planck scale physics. We also consider the issue of various possible physical mech...

  2. A stringy cloak for a classical singularity

    Energy Technology Data Exchange (ETDEWEB)

    Dabholkar, Atish [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Kallosh, Renata [Institute for Theoretical Physics, Department of Physics, Stanford University, Stanford, CA 94305 (United States); Maloney, Alexander [Institute for Theoretical Physics, Department of Physics, Stanford University, Stanford, CA 94305 (United States) and Theory Group, Stanford Linear Accelerator Center, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States)]. E-mail: maloney@slac.stanford.edu

    2004-12-01

    We consider a class of 4D supersymmetric black hole solutions, arising from string theory compactifications, which classically have vanishing horizon area and singular space-time geometry. String theory motivates the inclusion of higher derivative terms, which convert these singular classical solutions into regular black holes with finite horizon area. In particular, the supersymmetric attractor equations imply that the central charge, which determines the radius of the AdS{sub 2} x S{sup 2} near horizon geometry, acquires a non-vanishing value due to quantum effects. In this case quantum corrections to the Bekenstein-Hawking relation between entropy and area are large. This is the first explicit example where stringy quantum gravity effects replace a classical null singularity by a black hole with finite horizon area. (author)

  3. EDITORIAL: The plurality of optical singularities

    Science.gov (United States)

    Berry, Michael; Dennis, Mark; Soskin, Marat

    2004-05-01

    This collection of papers arose from an Advanced Research Workshop on Singular Optics, held at the Bogolyubov Institute in Kiev, Ukraine, during 24-28 June 2003. The workshop was generously financed by NATO, with welcome additional support from Institute of Physics Publishing and the National Academy of Sciences of Ukraine. There had been two previous international meetings devoted to singular optics, in Crimea in 1997 and 2000, reflecting the strong involvement of former Soviet Union countries in this research. Awareness of singular optics is growing within the wider optics community, indicated by symposia on the subject at several general optics meetings. As the papers demonstrate, the field of singular optics has reached maturity. Although the subject originated in an observation on ultrasound, it has been largely theory-driven until recently. Now, however, there is close contact between theory and experiment, and we speculate that this is one reason for its accelerated development. To single out particular papers for mention here would be invidious, and since the papers speak for themselves it is not necessary to describe them all. Instead, we will confine ourselves to a brief description of the main areas included in singular optics, to illustrate the broad scope of the subject. Optical vortices are lines of phase singularity: nodal lines where the intensity of the light, represented by a complex scalar field, vanishes. The subject has emerged from flatland, where the vortices are points characterized by topological charges, into the much richer world of vortex lines in three dimensions. By combining Laguerre-Gauss or Bessel beams, or reflecting light from plates with spiral steps, intricate arrangements can be generated, with vortices that are curved, looped, knotted, linked or braided. With light whose state of polarization varies with position, different singularities occur, associated with the vector nature of light. These are also lines, on which the

  4. Weights on cohomology and invariants of singularities

    CERN Document Server

    Arapura, Donu; Włodarczyk, Jarosław

    2011-01-01

    In this paper, we extract natural invariants of a singularity by using the Deligne weight filtration on the cohomology of an exceptional fibre of a resolution, and also on the intersection cohomology of the link. Our primary goal is to study and give natural bounds on the weights in terms of direct images of differential forms. These bounds can be made explicit for various standard classes such as rational, isolated normal Cohen-Macaulay and toroidal singularities, and lead to strong restrictions on the topology of these singularities. A secondary goal of this paper is to make the weight filtration, and related constructions, more widely accessible. So we have tried to make the presentation somewhat self contained. This is supersedes our earlier preprint arXiv:0902.4234.

  5. Automorphic forms with singularities on Grassmannians

    CERN Document Server

    Borcherds, R E

    1996-01-01

    We construct some families of automorphic forms on Grassmannians which have singularities along smaller sub Grassmannians, using a version of the theta correspondence extended to modular forms with poles at cusps. Some of the applications are as follows. We construct families of holomorphic automorphic forms which can be written as infinite products, which give many new examples of generalized Kac-Moody superalgebras. We extend the Shimura and Maass-Gritsenko correspondences to modular forms with singularities. We prove some congruences satisfied by the theta functions of positive definite lattices, and find a sufficient condition for a Lorentzian lattice to have a reflection group with a finite volume fundamental domain. We give some examples suggesting that these automorphic forms with singularities are related to Donaldson polynomials and to mirror symmetry for K3 surfaces.

  6. Equations of States in Singular Statistical Estimation

    CERN Document Server

    Watanabe, Sumio

    2007-01-01

    Learning machines which have hierarchical structures or hidden variables are singular statistical models because they are nonidentifiable and their Fisher information matrices are singular. In singular statistical models, neither the Bayes a posteriori distribution converges to the normal distribution nor the maximum likelihood estimator satisfies asymptotic normality. This is the main reason why it has been difficult to predict their generalization performances from trained states. In this paper, we study four errors, (1) Bayes generalization error, (2) Bayes training error, (3) Gibbs generalization error, and (4) Gibbs training error, and prove that there are mathematical relations among these errors. The formulas proved in this paper are equations of states in statistical estimation because they hold for any true distribution, any parametric model, and any a priori distribution. Also we show that Bayes and Gibbs generalization errors are estimated by Bayes and Gibbs training errors, and propose widely appl...

  7. Phantom cosmology without Big Rip singularity

    Energy Technology Data Exchange (ETDEWEB)

    Astashenok, Artyom V. [Baltic Federal University of I. Kant, Department of Theoretical Physics, 236041, 14, Nevsky st., Kaliningrad (Russian Federation); Nojiri, Shin' ichi, E-mail: nojiri@phys.nagoya-u.ac.jp [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Odintsov, Sergei D. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Institucio Catalana de Recerca i Estudis Avancats - ICREA and Institut de Ciencies de l' Espai (IEEC-CSIC), Campus UAB, Facultat de Ciencies, Torre C5-Par-2a pl, E-08193 Bellaterra (Barcelona) (Spain); Tomsk State Pedagogical University, Tomsk (Russian Federation); Yurov, Artyom V. [Baltic Federal University of I. Kant, Department of Theoretical Physics, 236041, 14, Nevsky st., Kaliningrad (Russian Federation)

    2012-03-23

    We construct phantom energy models with the equation of state parameter w which is less than -1, w<-1, but finite-time future singularity does not occur. Such models can be divided into two classes: (i) energy density increases with time ('phantom energy' without 'Big Rip' singularity) and (ii) energy density tends to constant value with time ('cosmological constant' with asymptotically de Sitter evolution). The disintegration of bound structure is confirmed in Little Rip cosmology. Surprisingly, we find that such disintegration (on example of Sun-Earth system) may occur even in asymptotically de Sitter phantom universe consistent with observational data. We also demonstrate that non-singular phantom models admit wormhole solutions as well as possibility of Big Trip via wormholes.

  8. The Singular Behavior of Jet Substructure Observables

    CERN Document Server

    Larkoski, Andrew J

    2016-01-01

    Jet substructure observables play a central role at the Large Hadron Collider for identifying the boosted hadronic decay products of electroweak scale resonances. The complete description of these observables requires understanding both the limit in which hard substructure is resolved, as well as the limit of a jet with a single hard core. In this paper we study in detail the perturbative structure of two prominent jet substructure observables, $N$-subjettiness and the energy correlation functions, as measured on background QCD jets. In particular, we focus on the distinction between the limits in which two-prong structure is resolved or unresolved. Depending on the choice of subjet axes, we demonstrate that at fixed order, $N$-subjettiness can manifest myriad behaviors in the unresolved region: smooth tails, end-point singularities, or singularities in the physical region. The energy correlation functions, by contrast, only have non-singular perturbative tails extending to the end point. We discuss the effec...

  9. Enveloping branes and brane-world singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios; Cotsakis, Spiros [CERN-Theory Division, Department of Physics, Geneva 23 (Switzerland); Klaoudatou, Ifigeneia [University of the Aegean, Research Group of Geometry, Dynamical Systems and Cosmology, Department of Information and Communication Systems Engineering, Samos (Greece)

    2014-12-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows one to determine the singularity structure of the solutions. The result is applied to brane-worlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parameterizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite-distance singularity contrary to previous claims. We then study the possibility of avoiding finite-distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes, however, this possibility as well. (orig.)

  10. Global embeddings for branes at toric singularities

    CERN Document Server

    Balasubramanian, Vijay; Braun, Volker; García-Etxebarria, Iñaki

    2012-01-01

    We describe how local toric singularities, including the Toric Lego construction, can be embedded in compact Calabi-Yau manifolds. We study in detail the addition of D-branes, including non-compact flavor branes as typically used in semi-realistic model building. The global geometry provides constraints on allowable local models. As an illustration of our discussion we focus on D3 and D7-branes on (the partially resolved) (dP0)^3 singularity, its embedding in a specific Calabi-Yau manifold as a hypersurface in a toric variety, the related type IIB orientifold compactification, as well as the corresponding F-theory uplift. Our techniques generalize naturally to complete intersections, and to a large class of F-theory backgrounds with singularities.

  11. Infinitesimal Lyapunov functions and singular-hyperbolicity

    CERN Document Server

    Araujo, Vitor

    2012-01-01

    We present an extension of the notion of infinitesimal Lyapunov function to singular flows on three-dimensional manifolds, and show how this technique provides a characterization of partially hyperbolic structures for invariant sets for such flows, and also of singular-hyperbolicity. In the absence of singularities, we can also rephrase uniform hyperbolicity with the language of infinitesimal Lyapunov functions. These conditions are expressed using the vector field X and its space derivative DX together with an infinitesimal Lyapunov function only and are reduced to checking that a certain symmetric operator is positive definite on the trapping region: we show how to express partial hyperbolicity using only the interplay between the infinitesimal generator X of the flow X_t, its derivative DX and the infinitesimal Lyapunov function.

  12. The Singularity Problem in Brane Cosmology

    Directory of Open Access Journals (Sweden)

    Ignatios Antoniadis

    2017-02-01

    Full Text Available We review results about the development and asymptotic nature of singularities in “brane–bulk” systems. These arise for warped metrics obeying the five-dimensional Einstein equations with fluid-like sources, and including a brane four-metric that is either Minkowski, de Sitter, or Anti-de Sitter. We characterize all singular Minkowski brane solutions, and look for regular solutions with nonzero curvature. We briefly comment on matching solutions, energy conditions, and finite Planck mass criteria for admissibility, and we briefly discuss the connection of these results to ambient theory.

  13. REGULARIZATION OF SINGULAR SYSTEMS BY OUTPUT FEEDBACK

    Institute of Scientific and Technical Information of China (English)

    De-lin Chu; Da-yong Cai

    2000-01-01

    Problem of regularization of a singular system by derivative and proportional output feedback is studied. Necessary and sufficient conditions are obtained under which a singular system can be regularized into a closed-loop system that is regular and of index at most one. The reduced form is given that can easily explore the system properties as well as the feedback to be determined. The main results of the present paper are based on orthogonal transformations. Therefore, they can be implemented by numerically stable ways.

  14. Quantum singularity of Levi-Civita spacetimes

    CERN Document Server

    Konkowski, D A; Wieland, C

    2004-01-01

    Quantum singularities in general relativistic spacetimes are determined by the behavior of quantum test particles. A static spacetime is quantum mechanically singular if the spatial portion of the wave operator is not essentially self-adjoint. Here Weyl's limit point-limit circle criterion is used to determine whether a wave operator is essentially self-adjoint. This test is then applied to scalar wave packets in Levi-Civita spacetimes to help elucidate the physical properties of the spacetimes in terms of their metric parameters.

  15. Singularity links with exotic Stein fillings

    OpenAIRE

    Özbağcı, Burak; Akhmedov, Anar

    2012-01-01

    arXiv:1206.2468v3 [math.GT] 14 May 2014 SINGULARITY LINKS WITH EXOTIC STEIN FILLINGS ANAR AKHMEDOV AND BURAK OZBAGCI ABSTRACT. In [4], it was shown that there exist infinitely many contact Seifert fibered 3-manifolds each of which admits infinitely many exotic (homeomorphic but pairwise non-diffeomorphic) simply-connected Stein fillings. Here we extend this result to a larger set of contact Seifert fibered 3-manifolds with many singular fibers and observe that these 3- ma...

  16. Loop Quantum Cosmology: Anisotropy and singularity resolution

    CERN Document Server

    Corichi, Alejandro; Montoya, Edison

    2012-01-01

    In this contribution we consider the issue of singularity resolution within loop quantum cosmology (LQC) for different homogeneous models. We present results of numerical evolutions of effective equations for both isotropic as well as anisotropic cosmologies, with and without spatial curvature. To address the issue of singularity resolution we examine the time evolution of geometrical and curvature invariants that yield information about the semiclassical spacetime geometry. We discuss generic behavior found for a variety of initial conditions. Finally, we show that the modifications which come from Loop Quantum Cosmology imply a non-chaotic effective behavior in the vacuum Bianchi IX model.

  17. Asymptotic stability of singularly perturbed differential equations

    Science.gov (United States)

    Artstein, Zvi

    2017-02-01

    Asymptotic stability is examined for singularly perturbed ordinary differential equations that may not possess a natural split into fast and slow motions. Rather, the right hand side of the equation is comprised of a singularly perturbed component and a regular one. The limit dynamics consists then of Young measures, with values being invariant measures of the fast contribution, drifted by the slow one. Relations between the asymptotic stability of the perturbed system and the limit dynamics are examined, and a Lyapunov functions criterion, based on averaging, is established.

  18. Singular Masas and Measure-Multiplicity Invariant

    CERN Document Server

    Mukherjee, Kunal

    2011-01-01

    In this paper we study relations between the \\emph{left-right-measure} and properties of singular masas. Part of the analysis is mainly concerned with masas for which the \\emph{left-right-measure} is the class of product measure. We provide examples of Tauer masas in the hyperfinite $\\rm{II}_{1}$ factor whose \\emph{left-right-measure} is the class of Lebesgue measure. We show that for each subset $S\\subseteq \\mathbb{N}$, there exist uncountably many pairwise non conjugate singular masas in the free group factors with \\emph{Puk\\'{a}nszky invariant} $S\\cup\\{\\infty\\}$.

  19. Numerical methods of computation of singular and hypersingular integrals

    Directory of Open Access Journals (Sweden)

    I. V. Boikov

    2001-01-01

    and technology one is faced with necessity of calculating different singular integrals. In analytical form calculation of singular integrals is possible only in unusual cases. Therefore approximate methods of singular integrals calculation are an active developing direction of computing in mathematics. This review is devoted to the optimal with respect to accuracy algorithms of the calculation of singular integrals with fixed singularity, Cauchy and Hilbert kernels, polysingular and many-dimensional singular integrals. The isolated section is devoted to the optimal with respect to accuracy algorithms of the calculation of the hypersingular integrals.

  20. Mechanics of human voice production and control

    Science.gov (United States)

    Zhang, Zhaoyan

    2016-01-01

    As the primary means of communication, voice plays an important role in daily life. Voice also conveys personal information such as social status, personal traits, and the emotional state of the speaker. Mechanically, voice production involves complex fluid-structure interaction within the glottis and its control by laryngeal muscle activation. An important goal of voice research is to establish a causal theory linking voice physiology and biomechanics to how speakers use and control voice to communicate meaning and personal information. Establishing such a causal theory has important implications for clinical voice management, voice training, and many speech technology applications. This paper provides a review of voice physiology and biomechanics, the physics of vocal fold vibration and sound production, and laryngeal muscular control of the fundamental frequency of voice, vocal intensity, and voice quality. Current efforts to develop mechanical and computational models of voice production are also critically reviewed. Finally, issues and future challenges in developing a causal theory of voice production and perception are discussed. PMID:27794319

  1. Native voice, self-concept and the moral case for personalized voice technology.

    Science.gov (United States)

    Nathanson, Esther

    2017-01-01

    Purpose (1) To explore the role of native voice and effects of voice loss on self-concept and identity, and survey the state of assistive voice technology; (2) to establish the moral case for developing personalized voice technology. Methods This narrative review examines published literature on the human significance of voice, the impact of voice loss on self-concept and identity, and the strengths and limitations of current voice technology. Based on the impact of voice loss on self and identity, and voice technology limitations, the moral case for personalized voice technology is developed. Results Given the richness of information conveyed by voice, loss of voice constrains expression of the self, but the full impact is poorly understood. Augmentative and alternative communication (AAC) devices facilitate communication but, despite advances in this field, voice output cannot yet express the unique nuances of individual voice. The ethical principles of autonomy, beneficence and equality of opportunity establish the moral responsibility to invest in accessible, cost-effective, personalized voice technology. Conclusions Although further research is needed to elucidate the full effects of voice loss on self-concept, identity and social functioning, current understanding of the profoundly negative impact of voice loss establishes the moral case for developing personalized voice technology. Implications for Rehabilitation Rehabilitation of voice-disordered patients should facilitate self-expression, interpersonal connectedness and social/occupational participation. Proactive questioning about the psychological and social experiences of patients with voice loss is a valuable entry point for rehabilitation planning. Personalized voice technology would enhance sense of self, communicative participation and autonomy and promote shared healthcare decision-making. Further research is needed to identify the best strategies to preserve and strengthen identity and sense of

  2. A Poet's Vision.

    Science.gov (United States)

    Marshall, Suzanne; Newman, Dan

    1997-01-01

    Describes a series of activities to help middle school students develop an artist's vision and then convey that vision through poetry. Describes how lessons progress from looking at concrete objects to observations of settings and characters, gradually adding memory and imagination to direct observation, and finishing with revision. Notes that…

  3. New Term, New Vision?

    Science.gov (United States)

    Ravenhall, Mark

    2011-01-01

    During the affluent noughties it was sometimes said of government that it had "more visions than Mystic Meg and more pilots than British Airways". In 2011, the pilots, the pathfinders, the new initiatives are largely gone--implementation is the name of the game--but the visions remain. The latest one, as it affects adult learners, is in…

  4. Synthesized night vision goggle

    Science.gov (United States)

    Zhou, Haixian

    2000-06-01

    A Synthesized Night Vision Goggle that will be described int his paper is a new type of night vision goggle with multiple functions. It consists of three parts: main observing system, picture--superimposed system (or Cathode Ray Tube system) and Charge-Coupled Device system.

  5. Copenhagen Energy Vision

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Rasmus Søgaard; Connolly, David

    The short-term goal for The City of Copenhagen is a CO2 neutral energy supply by the year 2025, and the long-term vision for Denmark is a 100% renewable energy (RE) supply by the year 2050. In this project, it is concluded that Copenhagen plays a key role in this transition. The long-term vision ...

  6. New Term, New Vision?

    Science.gov (United States)

    Ravenhall, Mark

    2011-01-01

    During the affluent noughties it was sometimes said of government that it had "more visions than Mystic Meg and more pilots than British Airways". In 2011, the pilots, the pathfinders, the new initiatives are largely gone--implementation is the name of the game--but the visions remain. The latest one, as it affects adult learners, is in the…

  7. Children's Voice or Children's Voices? How Educational Research Can Be at the Heart of Schooling

    Science.gov (United States)

    Stern, Julian

    2015-01-01

    There are problems with considering children and young people in schools as quite separate individuals, and with considering them as members of a single collectivity. The tension is represented in the use of "voice" and "voices" in educational debates. Voices in dialogue, in contrast to "children's voice", are…

  8. Voice complaints, risk factors for voice problems and history of voice problems in relation to puberty in female student teachers.

    NARCIS (Netherlands)

    Thomas, G.; Jong, F.I.C.R.S. de; Kooijman, P.G.C.; Donders, A.R.T.; Cremers, C.W.R.J.

    2006-01-01

    The aim of the study was to estimate voice complaints, risk factors for voice complaints and history of voice problems in student teachers before they embarked on their professional teaching career. A cross-sectional questionnaire survey was performed among female student teachers. The response rate

  9. Voice complaints, risk factors for voice problems and history of voice problems in relation to puberty in female student teachers.

    NARCIS (Netherlands)

    Thomas, G.; Jong, F.I.C.R.S. de; Kooijman, P.G.C.; Donders, A.R.T.; Cremers, C.W.R.J.

    2006-01-01

    The aim of the study was to estimate voice complaints, risk factors for voice complaints and history of voice problems in student teachers before they embarked on their professional teaching career. A cross-sectional questionnaire survey was performed among female student teachers. The response rate

  10. Clinical Trials in Vision Research

    Science.gov (United States)

    ... Eye Health Information > Clinical Trials in Vision Research Clinical Trials in Vision Research Clinical studies depend on people ... vision research in the United States. Basics of Clinical Trials What is a clinical trial? Clinical trials are ...

  11. Taking Care of Your Vision

    Science.gov (United States)

    ... of Healthy Breakfasts Shyness Taking Care of Your Vision KidsHealth > For Teens > Taking Care of Your Vision ... are important parts of keeping your peepers perfect. Vision Basics One of the best things you can ...

  12. Human voice recognition depends on language ability.

    Science.gov (United States)

    Perrachione, Tyler K; Del Tufo, Stephanie N; Gabrieli, John D E

    2011-07-29

    The ability to recognize people by their voice is an important social behavior. Individuals differ in how they pronounce words, and listeners may take advantage of language-specific knowledge of speech phonology to facilitate recognizing voices. Impaired phonological processing is characteristic of dyslexia and thought to be a basis for difficulty in learning to read. We tested voice-recognition abilities of dyslexic and control listeners for voices speaking listeners' native language or an unfamiliar language. Individuals with dyslexia exhibited impaired voice-recognition abilities compared with controls only for voices speaking their native language. These results demonstrate the importance of linguistic representations for voice recognition. Humans appear to identify voices by making comparisons between talkers' pronunciations of words and listeners' stored abstract representations of the sounds in those words.

  13. Quick Statistics about Voice, Speech, and Language

    Science.gov (United States)

    ... here Home » Health Info » Statistics and Epidemiology Quick Statistics About Voice, Speech, Language Voice, Speech, Language, and ... no 205. Hyattsville, MD: National Center for Health Statistics. 2015. Hoffman HJ, Li C-M, Losonczy K, ...

  14. Introduction: Textual and contextual voices of translation

    DEFF Research Database (Denmark)

    2017-01-01

    Voices – marks of the tangle of subjectivities involved in textual processes – constitute the very fabric of texts in general and translations in particular. The title of this book, Textual and Contextual Voices of Translation, refers both to textual voices, that is, the voices found within...... the translated texts, and to contextual voices, that is, the voices of those involved in shaping, commenting, or otherwise influencing the textual voices. The latter appear in prefaces, reviews, and other texts that surround the translated texts and provide them with a context. Our main claim is that studying...... both the textual and contextual voices helps us better understand and explain the complexity of both the translation process and the translation product. The dovetailed approach to translation research that is advocated in this book aims at highlighting the diversity of participants, power positions...

  15. Panoramic stereo sphere vision

    Science.gov (United States)

    Feng, Weijia; Zhang, Baofeng; Röning, Juha; Zong, Xiaoning; Yi, Tian

    2013-01-01

    Conventional stereo vision systems have a small field of view (FOV) which limits their usefulness for certain applications. While panorama vision is able to "see" in all directions of the observation space, scene depth information is missed because of the mapping from 3D reference coordinates to 2D panoramic image. In this paper, we present an innovative vision system which builds by a special combined fish-eye lenses module, and is capable of producing 3D coordinate information from the whole global observation space and acquiring no blind area 360°×360° panoramic image simultaneously just using single vision equipment with one time static shooting. It is called Panoramic Stereo Sphere Vision (PSSV). We proposed the geometric model, mathematic model and parameters calibration method in this paper. Specifically, video surveillance, robotic autonomous navigation, virtual reality, driving assistance, multiple maneuvering target tracking, automatic mapping of environments and attitude estimation are some of the applications which will benefit from PSSV.

  16. Machine Vision Handbook

    CERN Document Server

    2012-01-01

    The automation of visual inspection is becoming more and more important in modern industry as a consistent, reliable means of judging the quality of raw materials and manufactured goods . The Machine Vision Handbook  equips the reader with the practical details required to engineer integrated mechanical-optical-electronic-software systems. Machine vision is first set in the context of basic information on light, natural vision, colour sensing and optics. The physical apparatus required for mechanized image capture – lenses, cameras, scanners and light sources – are discussed followed by detailed treatment of various image-processing methods including an introduction to the QT image processing system. QT is unique to this book, and provides an example of a practical machine vision system along with extensive libraries of useful commands, functions and images which can be implemented by the reader. The main text of the book is completed by studies of a wide variety of applications of machine vision in insp...

  17. Color vision and dentistry.

    Science.gov (United States)

    Wasson, W; Schuman, N

    1992-05-01

    Color vision is a critical component of restorative and esthetic dentistry, but dentists, as a group, do not have their color vision tested at any time during their careers. A study was undertaken to ascertain the color-vision status of practicing dental personnel at the University of Tennessee, College of Dentistry. One hundred fifty individuals, 75 men and 75 women, were screened. The results corroborated the existing medical data for the general population. It was found that 9.3% of the men and none of the women exhibited color-vision defect. Since most dentists are male, this study demonstrates an area of potential weakness for some practitioners. Once a color-vision problem is found, it is simple to remedy by employing a team approach to shade matching or mechanical means of matching shades (by the practitioner). No ethnic or racial distinctions were detected, although these have been reported in other studies.

  18. Geometric singular perturbation theory in biological practice

    NARCIS (Netherlands)

    Hek, G.

    2010-01-01

    Geometric singular perturbation theory is a useful tool in the analysis of problems with a clear separation in time scales. It uses invariant manifolds in phase space in order to understand the global structure of the phase space or to construct orbits with desired properties. This paper explains an

  19. Footballs, Conical Singularities and the Liouville Equation

    CERN Document Server

    Redi, M

    2004-01-01

    We generalize the football shaped extra dimensions scenario to an arbitrary number of branes. The problem is related to the solution of the Liouville equation with singularities and explicit solutions are presented for the case of three branes. The tensions of the branes do not need to be tuned with each other but only satisfy mild global constraints.

  20. Classical resolution of singularities in dilaton cosmologies

    NARCIS (Netherlands)

    Bergshoeff, EA; Collinucci, A; Roest, D; Russo, JG; Townsend, PK

    2005-01-01

    For models of dilaton gravity with a possible exponential potential, such as the tensor-scalar sector of ITA supergravity, we show how cosmological solutions correspond to trajectories in a 2D Milne space (parametrized by the dilaton and the scale factor). Cosmological singularities correspond to po

  1. Bergman kernel and complex singularity exponent

    Institute of Scientific and Technical Information of China (English)

    LEE; HanJin

    2009-01-01

    We give a precise estimate of the Bergman kernel for the model domain defined by Ω F={(z,w) ∈ C n+1:Im w |F (z)| 2 > 0},where F=(f 1,...,f m) is a holomorphic map from C n to C m,in terms of the complex singularity exponent of F.

  2. Farewell to black hole horizons and singularities?

    CERN Document Server

    Corda, C; Cuesta, H J Mosquera; Robertson, S; Schild, R E

    2011-01-01

    We consider the fundamental issues which dominate the question about the existence or non-existence of black hole horizons and singularities from both of the theoretical and observational points of view, and discuss some of the ways that black hole singularities can be prevented from forming at a classical level, i.e. without arguments of quantum gravity. In this way, we argue that black holes could have a different nature with respect the common belief. In fact, even remaining very compact astrophysics objects, they could be devoid of horizons and singularities. Our analysis represents a key point within the debate on the path to unification of theories. As recently some scientists partially retrieved the old Einstein's opinion that quantum mechanics has to be subjected to a more general deterministic theory, a way to find solutions to the problem of black hole horizons and singularities at a semi-classical level, i.e. without discussions of quantum gravity, becomes a fundamental framework.

  3. Wheeler-DeWitt quantization and singularities

    CERN Document Server

    Falciano, Felipe Tovar; Struyve, Ward

    2015-01-01

    We consider a Bohmian approach to the Wheeler-DeWitt quantization of the Friedmann-Lemaitre-Robertson-Walker model and investigate the question whether or not there are singularities, in the sense that the universe reaches zero volume. We find that for generic wave functions (i.e., non-classical wave functions), there is a non-zero probability for a trajectory to be non-singular. This should be contrasted to the consistent histories approach for which it was recently shown by Craig and Singh that there is always a singularity. This result illustrates that the question of singularities depends much on which version of quantum theory one adopts. This was already pointed out by Pinto-Neto et al., albeit with a different Bohmian approach. Our current Bohmian approach agrees with the consistent histories approach by Craig and Singh for single-time histories, unlike the one studied earlier by Pinto-Neto et al. Although the trajectories are usually different in the two Bohmian approach, their qualitative behavior is...

  4. Journey Beyond the Schwarzschild Black Hole Singularity

    CERN Document Server

    Araya, Ignacio J; James, Albin

    2015-01-01

    We present the geodesical completion of the Schwarzschild black hole in four dimensions which covers the entire space in (u,v) Kruskal-Szekeres coordinates, including the spacetime behind the black and white hole singularities. The gravitational constant switches sign abruptly at the singularity, thus we interpret the other side of the singularity as a region of antigravity. The presence of such sign flips is a prediction of local (Weyl) scale invariant geodesically complete spacetimes which improve classical general relativity and string theory. We compute the geodesics for our new black hole and show that all geodesics of a test particle are complete. Hence, an ideal observer, that starts its journey in the usual space of gravity, can reach the other side of the singularity in a finite amount of proper time. As usual, an observer outside of the horizon cannot verify that such phenomena exist. However, the fact that there exist proper observers that can see this, is of fundamental significance for the constr...

  5. Resonance through a Strictly Singular Perturbation.

    Science.gov (United States)

    1981-04-01

    subspace of singularity with respect to H is empty. The question one now tries to answer is, if there exists a modification of the former definition...Foundations of Quantum Physics, chap. 5, sec. 3, Benjamin, London (1976). (7] J. Hadamard, Enseignement Math., 35, 5 (1936). (8) R. S. Phillips, Semi-groups

  6. Singularity and Community: Levinas and Democracy

    Science.gov (United States)

    Zhao, Guoping

    2016-01-01

    This article explores and extends Levinas's ideas of singularity and community as multiplicity and argues that his identification of language and discourse as the means to create ethical communities provides tangible possibilities for rebuilding genuine democracy in a humane world. These ideas help us reimagine school and classroom as communities…

  7. Quantum singularity of Levi-Civita spacetimes

    Science.gov (United States)

    Konkowski, Deborah; Helliwell, Thomas; Wieland, Chris; Reese, Cassidi

    2004-05-01

    Quantum singularities in general relativistic spacetimes are determined by the behavior of quantum test particles. A static spacetime is quantum mechanically singular [G.T. Horowitz and D. Marolf, Phys. Rev. D52, 5670 (1995)] if the spatial portion of the wave operator is not essentially self-adjoint on a C_0^∞ domain in L^2, a Hilbert space of square integrable functions. Here Weyl's limit point-limit circle criterion [M. Reed and B. Simon, Fourier Analysis and Self-Adjointness (New York: Academic Press, 1972)] is used to determine whether a wave operator is essentially self-adjoint. This test is then applied to scalar wave packets in Levi-Civita spacetimes with and without a cosmological constant to help elucidate the physical properties of the spacetimes. This discussion is based in part on a paper by D.A. Konkowski, T.M. Helliwell and C. Wieland [Class. Quantum Grav., 21, 265 (2004)]. Finally, the importance of the underlying Hilbert space is considered through a comparison in this instance of the notion of quantum singularity with the notion of wave singularity [A. Ishibashi and A. Hosoya, Phys. Rev. D60, 104028 (1999)].

  8. Singular Linear Differential Equations in Two Variables

    NARCIS (Netherlands)

    Braaksma, B.L.J.; Put, M. van der

    2008-01-01

    The formal and analytic classification of integrable singular linear differential equations has been studied among others by R. Gerard and Y. Sibuya. We provide a simple proof of their main result, namely: For certain irregular systems in two variables there is no Stokes phenomenon, i.e. there is no

  9. Singularity invariants related to Milnor fibers: survey

    CERN Document Server

    Budur, Nero

    2010-01-01

    This brief survey of some singularity invariants related to Milnor fibers should serve as a quick guide to references. We attempt to place things into a wide geometric context while leaving technicalities aside. We focus on relations among different invariants and on the practical aspect of computing them.

  10. Renormalization of singular potentials and power counting

    NARCIS (Netherlands)

    Long, B.; van Koick, U.; van Kolck, U.

    2008-01-01

    We use a toy model to illustrate how to build effective theories for singular potentials. We consider a central attractive 1/r(2) potential perturbed by a 1/r(4) correction. The power-counting rule, an important ingredient of effective theory, is established by seeking the minimum set of short-range

  11. Diamagnetism of quantum gases with singular potentials

    DEFF Research Database (Denmark)

    Briet, Philippe; Cornean, Horia; Savoie, Baptiste

    2010-01-01

    We consider a gas of quasi-free quantum particles confined to a finite box, subjected to singular magnetic and electric fields. We prove in great generality that the finite volume grand-canonical pressure is analytic with respect to the chemical potential and the intensity of the external magnetic...

  12. Bergman kernel and complex singularity exponent

    Institute of Scientific and Technical Information of China (English)

    CHEN BoYong; LEE HanJin

    2009-01-01

    We give a precise estimate of the Bergman kernel for the model domain defined by Ω_F = {(z,w) ∈ C~(n+1) : Imw - |F(z)|~2 > 0},where F = (f_1,... ,f_m) is a holomorphic map from C~n to C~m,in terms of the complex singularity exponent of F.

  13. Optical M\\"{o}bius Singularities

    CERN Document Server

    Freund, Isaac

    2008-01-01

    M\\"{o}bius strips with one, two, three, and four, half-twists are shown to be generic features of three-dimensional (nonparaxial) elliptically polarized light. The geometry and topology of these unusual singularities is described and the multitude of winding numbers that characterize their structures is enumerated; probabilities for the appearance of different configurations are presented.

  14. Singularity and Community: Levinas and Democracy

    Science.gov (United States)

    Zhao, Guoping

    2016-01-01

    This article explores and extends Levinas's ideas of singularity and community as multiplicity and argues that his identification of language and discourse as the means to create ethical communities provides tangible possibilities for rebuilding genuine democracy in a humane world. These ideas help us reimagine school and classroom as communities…

  15. A singular limit for compressible rotating fluids

    CERN Document Server

    Feireisl, Eduard; Novotny, Antonin

    2010-01-01

    We consider a singular limit problem for the Navier-Stokes system of a rotating compressible fluid, where the Rossby and Mach numbers tend simultaneously to zero. The limit problem is identified as the 2-D Navier-Stokes system in the ``horizontal'' variables containing an extra term that accounts for compressibility in the original system.

  16. Speaker's voice as a memory cue.

    Science.gov (United States)

    Campeanu, Sandra; Craik, Fergus I M; Alain, Claude

    2015-02-01

    Speaker's voice occupies a central role as the cornerstone of auditory social interaction. Here, we review the evidence suggesting that speaker's voice constitutes an integral context cue in auditory memory. Investigation into the nature of voice representation as a memory cue is essential to understanding auditory memory and the neural correlates which underlie it. Evidence from behavioral and electrophysiological studies suggest that while specific voice reinstatement (i.e., same speaker) often appears to facilitate word memory even without attention to voice at study, the presence of a partial benefit of similar voices between study and test is less clear. In terms of explicit memory experiments utilizing unfamiliar voices, encoding methods appear to play a pivotal role. Voice congruency effects have been found when voice is specifically attended at study (i.e., when relatively shallow, perceptual encoding takes place). These behavioral findings coincide with neural indices of memory performance such as the parietal old/new recollection effect and the late right frontal effect. The former distinguishes between correctly identified old words and correctly identified new words, and reflects voice congruency only when voice is attended at study. Characterization of the latter likely depends upon voice memory, rather than word memory. There is also evidence to suggest that voice effects can be found in implicit memory paradigms. However, the presence of voice effects appears to depend greatly on the task employed. Using a word identification task, perceptual similarity between study and test conditions is, like for explicit memory tests, crucial. In addition, the type of noise employed appears to have a differential effect. While voice effects have been observed when white noise is used at both study and test, using multi-talker babble does not confer the same results. In terms of neuroimaging research modulations, characterization of an implicit memory effect

  17. Tagore’s Dark Vision of Humanity

    Directory of Open Access Journals (Sweden)

    Alok BHALLA

    2013-04-01

    Full Text Available Tagore struggled against his dark vision of humanity to assert that the earth was a place of hierophanies and human life had a divine purpose. He failed. He called, with skepticism, for peace, equality and the restoration of earth’s loveliness: “I know I am crying in the wilderness, when I raise my voice of warning…” In a war-haunted and hungry Europe and Asia, he was confronted by a strange, cruel, and obstinately tribal world with its “legacy of ruin.” Though he asserted till his death in 1940 that he could never “commit the grievous sin of losing faith in man,” he could not turn away from “the crumbling ruins of … civilization….”

  18. Machine vision is not computer vision

    Science.gov (United States)

    Batchelor, Bruce G.; Charlier, Jean-Ray

    1998-10-01

    The identity of Machine Vision as an academic and practical subject of study is asserted. In particular, the distinction between Machine Vision on the one hand and Computer Vision, Digital Image Processing, Pattern Recognition and Artificial Intelligence on the other is emphasized. The article demonstrates through four cases studies that the active involvement of a person who is sensitive to the broad aspects of vision system design can avoid disaster and can often achieve a successful machine that would not otherwise have been possible. This article is a transcript of the key- note address presented at the conference. Since the proceedings are prepared and printed before the conference, it is not possible to include a record of the response to this paper made by the delegates during the round-table discussion. It is hoped to collate and disseminate these via the World Wide Web after the event. (A link will be provided at http://bruce.cs.cf.ac.uk/bruce/index.html.).

  19. Literature and information in vision care and vision science.

    Science.gov (United States)

    Goss, David A

    2008-11-01

    The explosion of information in vision care and vision science makes keeping up with the literature and information in the field challenging. This report examines the nature of literature and information in vision care and vision science. A variety of topics are discussed, including the general nature of scientific and clinical journals, journals in vision science and vision care, resources available for searches for literature and information, and issues involved in the evaluation of journals and other information sources. Aspects of the application of citation analysis to vision care and vision science are reviewed, and a new citation analysis of a leading textbook in vision care (Borish's Clinical Refraction) is presented. This report is directed toward anyone who wants to be more informed about the literature of vision care and vision science, whether they are students, clinicians, educators, or librarians.

  20. Positive Solutions for Higher Order Singular -Laplacian Boundary Value Problems

    Indian Academy of Sciences (India)

    Guoliang Shi; Junhong Zhang

    2008-05-01

    This paper investigates $2m-\\mathrm{th}(m≥ 2)$ order singular -Laplacian boundary value problems, and obtains the necessary and sufficient conditions for existence of positive solutions for sublinear 2-th order singular -Laplacian BVPs on closed interval.

  1. The geometry of singularities and the black hole information paradox

    CERN Document Server

    Stoica, Ovidiu Cristinel

    2015-01-01

    The information loss occurs in an evaporating black hole only if the time evolution ends at the singularity. But as we shall see, the black hole solutions admit analytical extensions beyond the singularities, to globally hyperbolic solutions. The method used is similar to that for the apparent singularity at the event horizon, but at the singularity, the resulting metric is degenerate. When the metric is degenerate, the covariant derivative, the curvature, and the Einstein equation become singular. However, recent advances in the geometry of spacetimes with singular metric show that there are ways to extend analytically the Einstein equation and other field equations beyond such singularities. This means that the information can get out of the singularity. In the case of charged black holes, the obtained solutions have {\

  2. Dynamics of learning near singularities in layered networks.

    Science.gov (United States)

    Wei, Haikun; Zhang, Jun; Cousseau, Florent; Ozeki, Tomoko; Amari, Shun-Ichi

    2008-03-01

    We explicitly analyze the trajectories of learning near singularities in hierarchical networks, such as multilayer perceptrons and radial basis function networks, which include permutation symmetry of hidden nodes, and show their general properties. Such symmetry induces singularities in their parameter space, where the Fisher information matrix degenerates and odd learning behaviors, especially the existence of plateaus in gradient descent learning, arise due to the geometric structure of singularity. We plot dynamic vector fields to demonstrate the universal trajectories of learning near singularities. The singularity induces two types of plateaus, the on-singularity plateau and the near-singularity plateau, depending on the stability of the singularity and the initial parameters of learning. The results presented in this letter are universally applicable to a wide class of hierarchical models. Detailed stability analysis of the dynamics of learning in radial basis function networks and multilayer perceptrons will be presented in separate work.

  3. São Carlos Workshop on Real and Complex Singularities

    CERN Document Server

    Ruas, Maria

    2007-01-01

    The São Carlos Workshop on Real and Complex Singularities is the longest running workshop in singularities. It is held every two years and is a key international event for people working in the field. This volume contains papers presented at the eighth workshop, held at the IML, Marseille, July 19–23, 2004. The workshop offers the opportunity to establish the state of the art and to present new trends, new ideas and new results in all of the branches of singularities. This is reflected by the contributions in this book. The main topics discussed are equisingularity of sets and mappings, geometry of singular complex analytic sets, singularities of mappings, characteristic classes, classification of singularities, interaction of singularity theory with some of the new ideas in algebraic geometry imported from theoretical physics, and applications of singularity theory to geometry of surfaces in low dimensional euclidean spaces, to differential equations and to bifurcation theory.

  4. Numerical solution of the Kolmogorov-Feller equation with singularities

    Science.gov (United States)

    Baranov, N. A.; Turchak, L. I.

    2010-02-01

    A method is proposed for solving the Kolmogorov-Feller integro-differential equation with kernels containing delta function singularities. The method is based on a decomposition of the solution into regular and singular parts.

  5. The second pluri-genus of smoothable Gorenstein surface singularities

    Institute of Scientific and Technical Information of China (English)

    YAU; Stephen; S.; T.

    2010-01-01

    For complete intersection isolated surface singularities, Okuma gave a formula for the second plurigenus relating geometry genus, Milnor number and Tjurina number. We generalize Okuma’s theorem to Gorenstein smoothable surface singularities.

  6. Voicing Consciousness: The Mind in Writing

    Science.gov (United States)

    Luce-Kapler, Rebecca; Catlin, Susan; Sumara, Dennis; Kocher, Philomene

    2011-01-01

    In this paper, the authors investigate the enduring power of voice as a concept in writing pedagogy. They argue that one can benefit from considering Elbow's assertion that both text and voice be considered as important aspects of written discourse. In particular, voice is a powerful metaphor for the material, social and historical nature of…

  7. Understanding the 'Anorexic Voice' in Anorexia Nervosa.

    Science.gov (United States)

    Pugh, Matthew; Waller, Glenn

    2016-07-20

    In common with individuals experiencing a number of disorders, people with anorexia nervosa report experiencing an internal 'voice'. The anorexic voice comments on the individual's eating, weight and shape and instructs the individual to restrict or compensate. However, the core characteristics of the anorexic voice are not known. This study aimed to develop a parsimonious model of the voice characteristics that are related to key features of eating disorder pathology and to determine whether patients with anorexia nervosa fall into groups with different voice experiences. The participants were 49 women with full diagnoses of anorexia nervosa. Each completed validated measures of the power and nature of their voice experience and of their responses to the voice. Different voice characteristics were associated with current body mass index, duration of disorder and eating cognitions. Two subgroups emerged, with 'weaker' and 'stronger' voice experiences. Those with stronger voices were characterized by having more negative eating attitudes, more severe compensatory behaviours, a longer duration of illness and a greater likelihood of having the binge-purge subtype of anorexia nervosa. The findings indicate that the anorexic voice is an important element of the psychopathology of anorexia nervosa. Addressing the anorexic voice might be helpful in enhancing outcomes of treatments for anorexia nervosa, but that conclusion might apply only to patients with more severe eating psychopathology. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Voice and culture: A prospect theory approach

    NARCIS (Netherlands)

    Paddock, E.L.; Ko, Junsu; Cropanzano, R.; Bagger, J.; El Akremi, A.; Camerman, A.; Greguras, G. J.; Mladinic, A.; Moliner, C.; Nam, K.; Törnblom, K.; Van den Bos, Kees

    2015-01-01

    The present study examines the congruence of individuals' minimum preferred amounts of voice with the prospect theory value function across nine countries. Accounting for previously ignored minimum preferred amounts of voice and actual voice amounts integral to testing the steepness of gain and loss

  9. Finding Voice: Learning about Language and Power

    Science.gov (United States)

    Christensen, Linda

    2011-01-01

    Christensen discusses why teachers need to teach students "voice" in its social and political context, to show the intersection of voice and power, to encourage students to ask, "Whose voices get heard? Whose are marginalized?" As Christensen writes, "Once students begin to understand that Standard English is one language among many, we can help…

  10. Analyzing the mediated voice - a datasession

    DEFF Research Database (Denmark)

    Lawaetz, Anna

    Broadcasted voices are technologically manipulated. In order to achieve a certain autencity or sound of “reality” paradoxically the voices are filtered and trained in order to reach the listeners. This “mis-en-scene” is important knowledge when it comes to the development of a consistent method o...... of analysis of the mediated voice...

  11. Analyzing the mediated voice - a datasession

    DEFF Research Database (Denmark)

    Lawaetz, Anna

    Broadcasted voices are technologically manipulated. In order to achieve a certain autencity or sound of “reality” paradoxically the voices are filtered and trained in order to reach the listeners. This “mis-en-scene” is important knowledge when it comes to the development of a consistent method...... of analysis of the mediated voice...

  12. Voice and culture: A prospect theory approach

    NARCIS (Netherlands)

    Paddock, E.L.; Ko, Junsu; Cropanzano, R.; Bagger, J.; El Akremi, A.; Camerman, A.; Greguras, G. J.; Mladinic, A.; Moliner, C.; Nam, K.; Törnblom, K.; Van den Bos, Kees

    2015-01-01

    The present study examines the congruence of individuals' minimum preferred amounts of voice with the prospect theory value function across nine countries. Accounting for previously ignored minimum preferred amounts of voice and actual voice amounts integral to testing the steepness of gain and loss

  13. "Voice Forum" The Human Voice as Primary Instrument in Music Therapy

    DEFF Research Database (Denmark)

    Pedersen, Inge Nygaard; Storm, Sanne

    2009-01-01

    Aspects will be drawn on the human voice as tool for embodying our psychological and physiological state, and attempting integration of feelings. Presentations and dialogues on different methods and techniques in "Therapy related body-and voice work.", as well as the human voice as a tool for non...... for nonverbal orientation and information both to our selves and others. Focus on training on the voice instrument, the effect and impact of the human voice, and listening perspectives...

  14. On the strength of the Kerr singularity and cosmic censorship

    CERN Document Server

    Rudnicki, W

    2000-01-01

    It has been suggested by Israel that the Kerr singularity cannot be strong in the sense of Tipler, for it tends to cause repulsive effects. We show here that, contrary to that suggestion, nearly all null geodesics reaching this singularity do in fact terminate in Tipler's strong curvature singularity. Implications of this result are discussed in the context of an earlier cosmic censorship theorem which constraints the occurrence of Kerr-like naked singularities in generic collapse situations.

  15. Naked singularities in Tolman-Bondi-de Sitter collapse

    CERN Document Server

    Gonçalves, S

    2001-01-01

    We study the formation of central naked singularities in spherical dust collapse with a cosmological constant. We find that the central curvature singularity is locally naked, Tipler strong, and generic, in the sense that it forms from a non-zero-measure set of regular initial data. We also find that the Weyl and Ricci curvature scalars diverge at the singularity, with the former dominating over the latter, thereby signaling the non-local origin of the singularity.

  16. Quantum probes of timelike naked singularity with scalar hair

    OpenAIRE

    Svitek, O.; Tahamtan, T.

    2016-01-01

    We study the curvature singularity resolution via quantum fields on a fixed background based on Klein--Gordon and Dirac equations for a static spacetime with a scalar field producing a timelike naked singularity. We show that both Klein--Gordon and Dirac quantum fields see this singularity. Subsequently we check the results by applying the maximal acceleration existence in Covariant Loop Quantum Gravity described recently and obtain the resolution of singularity. In the process we study the g...

  17. Resolution of SU(2) monopole singularities by oxidation

    CERN Document Server

    Bueno, Pablo; Meessen, Patrick; Ortin, Tomas

    2015-01-01

    We show how "colored" SU(2) BPS monopoles (that is: SU(2) monopoles satisfying the Bogomol'nyi equation whose Higgs field and magnetic charge vanish at infinity and which are singular at the origin) can be obtained from the BPST instanton by a singular dimensional reduction, explaining the origin of the singularity and implying that the singularity can be cured by the oxidation of the solution. We study the oxidation of other monopole solutions in this scheme.

  18. Resolution of SU (2) monopole singularities by oxidation

    Science.gov (United States)

    Bueno, Pablo; Meessen, Patrick; Ortín, Tomás; Ramírez, Pedro F.

    2015-06-01

    We show how colored SU (2) BPS monopoles (that is: SU (2) monopoles satisfying the Bogomol'nyi equation whose Higgs field and magnetic charge vanish at infinity and which are singular at the origin) can be obtained from the BPST instanton by a singular dimensional reduction, explaining the origin of the singularity and implying that the singularity can be cured by the oxidation of the solution. We study the oxidation of other monopole solutions in this scheme.

  19. Resolution of SU(2 monopole singularities by oxidation

    Directory of Open Access Journals (Sweden)

    Pablo Bueno

    2015-06-01

    Full Text Available We show how colored SU(2 BPS monopoles (that is: SU(2 monopoles satisfying the Bogomol'nyi equation whose Higgs field and magnetic charge vanish at infinity and which are singular at the origin can be obtained from the BPST instanton by a singular dimensional reduction, explaining the origin of the singularity and implying that the singularity can be cured by the oxidation of the solution. We study the oxidation of other monopole solutions in this scheme.

  20. Quantum probes of timelike naked singularity with scalar hair

    CERN Document Server

    Svítek, O

    2016-01-01

    We study the curvature singularity resolution via quantum fields on a fixed background based on Klein--Gordon and Dirac equations for a static spacetime with a scalar field producing a timelike naked singularity. We show that both Klein--Gordon and Dirac quantum fields see this singularity. Subsequently we check the results by applying the maximal acceleration existence in Covariant Loop Quantum Gravity described recently and obtain the resolution of singularity. In the process we study the geodesics in the spacetime.

  1. Soliton induced singularities in 2d gravity and their evaporation

    CERN Document Server

    Vaz, C; Vaz, Cenalo; Witten, Louis

    1995-01-01

    Positive energy singularities induced by Sine-Gordon solitons in 1+1 dimensional dilaton gravity with positive and negative cosmological constant are considered. When the cosmological constant is positive, the singularities combine a white hole, a timelike singularity and a black hole joined smoothly near the soliton center. When the cosmological constant is negative, the solutions describe two timelike singularities joined smoothly near the soliton center. We describe these spacetimes and examine their evaporation in the one loop approximation.

  2. Voice-Specialized Speech-Language Pathologist's Criteria for Discharge from Voice Therapy.

    Science.gov (United States)

    Gillespie, Amanda I; Gartner-Schmidt, Jackie

    2017-08-07

    No standard protocol exists to determine when a patient is ready and able to be discharged from voice therapy. The aim of the present study was to determine what factors speech-language pathologists (SLPs) deem most important when discharging a patient from voice therapy. A second aim was to determine if responses differed based on years of voice experience. Step 1: Seven voice-specialized SLPs generated a list of items thought to be relevant to voice therapy discharge. Step 2: Fifty voice-specialized SLPs rated each item on the list in terms of importance in determining discharge from voice therapy. Step 1: Four themes emerged-outcome measures, laryngeal appearance, SLP perceptions, and patient factors-as important items when determining discharge from voice therapy. Step 2: The top five most important criteria for discharge readiness were that the patient had to be able to (1) independently use a better voice (transfer), (2) function with his or her new voice production in activities of daily living (transfer), (3) differentiate between good and bad voice, (4) take responsibility for voice, and (5) sound better from baseline. Novice and experienced clinicians agreed between 94% and 97% concerning what was deemed "very important." SLPs agree that a patient's ability to use voice techniques in conversation and real-life situations outside of the therapy room are the most important determinants for voice therapy discharge. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  3. Naked Singularities in Spherically Symmetric, Self-Similar Spacetimes

    CERN Document Server

    Wagh, S M; Wagh, Sanjay M.; Govinder, Keshlan S.

    2001-01-01

    We show that all known naked singularities in spherically symmetric self-similar spacetimes arise as a result of singular initial matter distribution. This is a result of the peculiarity of the coordinate transformation that takes these spacetimes into a separable form. Therefore, these examples of naked singularities are of no apparent consequence to astrophysical observations or theories.

  4. THE COLLOCATION METHODS FOR SINGULAR INTEGRAL EQUATIONS WITH CAUCHY KERNELS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper applies the singular integral operators,singular quadrature operators and discretization matrices associated withsingular integral equations with Cauchy kernels, which are established in [1],to give a unified framework for various collocation methods of numericalsolutions of singular integral equations with Cauchy kernels. Under theframework, the coincidence of the direct quadrature method and the indirectquadrature method is very simple and obvious.

  5. 7 CFR 46.1 - Words in singular form.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Words in singular form. 46.1 Section 46.1 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Words in singular form. Words in this part in the singular form shall be deemed to import the...

  6. 7 CFR 61.1 - Words in singular form.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Words in singular form. 61.1 Section 61.1 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Words in singular form. Words used in the regulations in this subpart in the singular form shall...

  7. On Weakly Singular Versions of Discrete Nonlinear Inequalities and Applications

    Directory of Open Access Journals (Sweden)

    Kelong Cheng

    2014-01-01

    Full Text Available Some new weakly singular versions of discrete nonlinear inequalities are established, which generalize some existing weakly singular inequalities and can be used in the analysis of nonlinear Volterra type difference equations with weakly singular kernels. A few applications to the upper bound and the uniqueness of solutions of nonlinear difference equations are also involved.

  8. 7 CFR 1200.50 - Words in the singular form.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Words in the singular form. 1200.50 Section 1200.50 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING....50 Words in the singular form. Words in this subpart in the singular form shall be deemed to import...

  9. 7 CFR 900.36 - Words in the singular form.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Words in the singular form. 900.36 Section 900.36 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Marketing Orders § 900.36 Words in the singular form. Words in this subpart in the singular form shall be...

  10. 7 CFR 900.100 - Words in the singular form.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Words in the singular form. 900.100 Section 900.100 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Words in the singular form. Words in this subpart in the singular form shall be deemed to import the...

  11. On Multiple Singular Integrals along Polynomial Curves with Rough Kernels

    Institute of Scientific and Technical Information of China (English)

    Huo Xiong WU; Shan Zhi YANG

    2008-01-01

    This paper is devoted to the study of a class of singular integral operators deffned by polyno-mial mappings on product domains.Some rather weak size conditions,which imply the Lp boundedness of these singular integral operators as well as the corresponding maximal truncated singular integral operators for some fixed 1

  12. RANDOM SINGULAR INTEGRAL OF RANDOM PROCESS WITH SECOND ORDER MOMENT

    Institute of Scientific and Technical Information of China (English)

    Wang Chuanrong

    2005-01-01

    This paper discussses the random singular integral of random process with second order moment, establishes the concepts of the random singular integral and proves that it's a linear bounded operator of space Hα(L)(m, s). Then Plemelj formula and some other properties for random singular integral are proved.

  13. Carter subgroups of singular classical groups over finite fields

    Institute of Scientific and Technical Information of China (English)

    高有; 石新华

    2004-01-01

    Let Fq be a finite field with qelements whereq = pα. In the present paper, the authors study the existence and structure of Carter subgroups of singular symplectic group Sp (Fq), singular unitary group U ( Fq2 ) and singular orthogonal group O ( Fq ) ( n is even) over finite fields Fq.

  14. Behavior of Friedmann-Lemaître-Robertson-Walker Singularities

    Science.gov (United States)

    Fernández-Jambrina, L.

    2016-08-01

    In Stoica (Int. J. Theor. Phys. 55, 71-80, 2016) a regularization procedure is suggested for regularizing Big Bang singularities in Friedmann-Lemaître-Robertson-Walker (FLRW) spacetimes. We argue that this procedure is only appliable to one case of Big Bang singularities and does not affect other types of singularities.

  15. Anchoring visions in organizations

    DEFF Research Database (Denmark)

    Simonsen, Jesper

    1999-01-01

    This paper introduces the term 'anchoring' within systems development: Visions, developed through early systems design within an organization, need to be deeply rooted in the organization. A vision's rationale needs to be understood by those who decide if the vision should be implemented as well...... as by those involved in the actual implementation. A model depicting a recent trend within systems development is presented: Organizations rely on purchasing generic software products and/or software development outsourced to external contractors. A contemporary method for participatory design, where...

  16. Visions of the City

    DEFF Research Database (Denmark)

    Pinder, David

    hopes and dreams of modern urbanism. It also contests current claims about the 'end of utopia', arguing that reconsidering earlier projects can play a critical role in developing utopian perspectives today. Through the study of utopian visions, it aims to rekindle elements of utopianism itself.......Visions of the City is a dramatic account of utopian urbanism in the twentieth century. It explores radical demands for new spaces and ways of living, and considers their effects on planning, architecture and struggles to shape urban landscapes. Such visions, it shows, have played a crucial role...

  17. The development of the Spanish verb ir into auxiliary of voice

    DEFF Research Database (Denmark)

    Vinther, Thora

    2005-01-01

    spanish, syntax, grammaticalisation, past participle, passive voice, middle voice, language development......spanish, syntax, grammaticalisation, past participle, passive voice, middle voice, language development...

  18. Objective Voice Parameters in Colombian School Workers with Healthy Voices

    Directory of Open Access Journals (Sweden)

    Lady Catherine Cantor Cutiva

    2015-09-01

    Full Text Available Objectives: To characterize the objective voice parameters among school workers, and to identi­fy associated factors of three objective voice parameters, namely fundamental frequency, sound pressure level and maximum phonation time. Materials and methods: We conducted a cross-sectional study among 116 Colombian teachers and 20 Colombian non-teachers. After signing the informed consent form, participants filled out a questionnaire. Then, a voice sample was recorded and evaluated perceptually by a speech therapist and by objective voice analysis with praat software. Short-term environmental measurements of sound level, temperature, humi­dity, and reverberation time were conducted during visits at the workplaces, such as classrooms and offices. Linear regression analysis was used to determine associations between individual and work-related factors and objective voice parameters. Results: Compared with men, women had higher fundamental frequency (201 Hz for teachers and 209 for non-teachers vs. 120 Hz for teachers and 127 for non-teachers and sound pressure level (82 dB vs. 80 dB, and shorter maximum phonation time (around 14 seconds vs. around 16 seconds. Female teachers younger than 50 years of age evidenced a significant tendency to speak with lower fundamental frequen­cy and shorter mpt compared with female teachers older than 50 years of age. Female teachers had significantly higher fundamental frequency (66 Hz, higher sound pressure level (2 dB and short phonation time (2 seconds than male teachers. Conclusion: Female teachers younger than 50 years of age had significantly lower F0 and shorter mpt compared with those older than 50 years of age. The multivariate analysis showed that gender was a much more important determinant of variations in F0, spl and mpt than age and teaching occupation. Objectively measured temperature also contributed to the changes on spl among school workers.

  19. Playful Interaction with Voice Sensing Modular Robots

    DEFF Research Database (Denmark)

    Heesche, Bjarke; MacDonald, Ewen; Fogh, Rune

    2013-01-01

    This paper describes a voice sensor, suitable for modular robotic systems, which estimates the energy and fundamental frequency, F0, of the user’s voice. Through a number of example applications and tests with children, we observe how the voice sensor facilitates playful interaction between...... children and two different robot configurations. In future work, we will investigate if such a system can motivate children to improve voice control and explore how to extend the sensor to detect emotions in the user’s voice....

  20. Vision Problems in the U.S.

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  1. VOICE QUALITY BEFORE AND AFTER THYROIDECTOMY

    Directory of Open Access Journals (Sweden)

    Dora CVELBAR

    2016-04-01

    Full Text Available Introduction: Voice disorders are a well-known complication which is often associated with thyroid gland diseases and because voice is still the basic mean of communication it is very important to maintain its quality healthy. Objectives: The aim of this study referred to questions whether there is a statistically significant difference between results of voice self-assessment, perceptual voice assessment and acoustic voice analysis before and after thyroidectomy and whether there are statistically significant correlations between variables of voice self-assessment, perceptual assessment and acoustic analysis before and after thyroidectomy. Methods: This scientific research included 12 participants aged between 41 and 76. Voice self-assessment was conducted with the help of Croatian version of Voice Handicap Index (VHI. Recorded reading samples were used for perceptual assessment and later evaluated by two clinical speech and language therapists. Recorded samples of phonation were used for acoustic analysis which was conducted with the help of acoustic program Praat. All of the data was processed through descriptive statistics and nonparametric statistical methods. Results: Results showed that there are statistically significant differences between results of voice self-assessments and results of acoustic analysis before and after thyroidectomy. Statistically significant correlations were found between variables of perceptual assessment and acoustic analysis. Conclusion: Obtained results indicate the importance of multidimensional, preoperative and postoperative assessment. This kind of assessment allows the clinician to describe all of the voice features and provides appropriate recommendation for further rehabilitation to the patient in order to optimize voice outcomes.

  2. Beyond Insularity: Releasing the Voices.

    Science.gov (United States)

    Greene, Maxine

    1993-01-01

    Aspects of English-as-a-Second-Language are discussed from the standpoint of a teacher-educator with a particular interest in philosophy, the arts, and humanities and what they signify for the schools. The idea of giving voice to all viewpoints and sociocultural circumstances is considered for content learning and heterogeneous grouping. (Contains…

  3. A voice and nothing more

    DEFF Research Database (Denmark)

    Mebus, Andreas Nozic Lindgren

    2012-01-01

    Andreas Mebus fokuserer herefter på et helt konkret aspekt af talen, nemlig ”stemmen” i sin artikel ”A voice and nothing more – en filosofisk udredning af stemmen”. Gennem Mladen Dolars teori om stemmen, redegør Mebus for de forskellige aspekter ved stemmen; som bærer af mening, som æstetisk...

  4. Voice, Citizenship, and Civic Action

    DEFF Research Database (Denmark)

    Tufte, Thomas

    2014-01-01

    In recent years the world has experienced a resurgence in practices of bottom-up communication for social change, a plethora of agency in which claims for voice and citizenship through massive civic action have conquered center stage in the public debate. This resurgence has sparked a series...

  5. FILTWAM and Voice Emotion Recognition

    NARCIS (Netherlands)

    Bahreini, Kiavash; Nadolski, Rob; Westera, Wim

    2014-01-01

    This paper introduces the voice emotion recognition part of our framework for improving learning through webcams and microphones (FILTWAM). This framework enables multimodal emotion recognition of learners during game-based learning. The main goal of this study is to validate the use of microphone d

  6. The Performing Voice of Radio

    DEFF Research Database (Denmark)

    Lawaetz, Anna

    The ongoing international development of opening media archives for researchers as well as for broader audiences calls for a closer discussion of the mediated voice and how to analyse it. Which parameters can be analysed and which parameters are not covered by the analysis? Furthermore, how do we...

  7. Voice and choice by delegation

    NARCIS (Netherlands)

    van de Bovenkamp, H.; Vollaard, H.; Trappenburg, M.; Grit, K

    2013-01-01

    In many Western countries, options for citizens to influence public services are increased to improve the quality of services and democratize decision making. Possibilities to influence are often cast into Albert Hirschman's taxonomy of exit (choice), voice, and loyalty. In this article we identify

  8. Work-related voice disorder

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo Przysiezny

    2015-04-01

    Full Text Available INTRODUCTION: Dysphonia is the main symptom of the disorders of oral communication. However, voice disorders also present with other symptoms such as difficulty in maintaining the voice (asthenia, vocal fatigue, variation in habitual vocal fundamental frequency, hoarseness, lack of vocal volume and projection, loss of vocal efficiency, and weakness when speaking. There are several proposals for the etiologic classification of dysphonia: functional, organofunctional, organic, and work-related voice disorder (WRVD.OBJECTIVE: To conduct a literature review on WRVD and on the current Brazilian labor legislation.METHODS: This was a review article with bibliographical research conducted on the PubMed and Bireme databases, using the terms "work-related voice disorder", "occupational dysphonia", "dysphonia and labor legislation", and a review of labor and social security relevant laws.CONCLUSION: WRVD is a situation that frequently is listed as a reason for work absenteeism, functional rehabilitation, or for prolonged absence from work. Currently, forensic physicians have no comparative parameters to help with the analysis of vocal disorders. In certain situations WRVD may cause, work disability. This disorder may be labor-related, or be an adjuvant factor to work-related diseases.

  9. The Performing Voice of Radio

    DEFF Research Database (Denmark)

    Lawaetz, Anna

    The ongoing international development of opening media archives for researchers as well as for broader audiences calls for a closer discussion of the mediated voice and how to analyse it. Which parameters can be analysed and which parameters are not covered by the analysis? Furthermore, how do we...

  10. Adolescent Leadership: The Female Voice

    Science.gov (United States)

    Archard, Nicole

    2013-01-01

    This research investigated the female adolescent view of leadership by giving voice to student leaders through focus group discussions. The questions: What is leadership? Where/how was leadership taught?, and How was leadership practised? were explored within the context of girls' schools located in Australia, with one school located in South…

  11. FILTWAM and Voice Emotion Recognition

    NARCIS (Netherlands)

    Bahreini, Kiavash; Nadolski, Rob; Westera, Wim

    2014-01-01

    This paper introduces the voice emotion recognition part of our framework for improving learning through webcams and microphones (FILTWAM). This framework enables multimodal emotion recognition of learners during game-based learning. The main goal of this study is to validate the use of microphone

  12. Voicing children's critique and utopias

    DEFF Research Database (Denmark)

    Husted, Mia; Lind, Unni

    2016-01-01

    , designed to accommodate children's participation through graphic illustrations of young children's critique and utopias. The study is informed by a commitment to democratic participation and processes (Reason and Bradbury 2001, Gunnarsson et al. 2016). Ethical guidelines implied dialogues and discussions......, children's voice, critique and utopias, pedagogical work...

  13. Women's Voices in Experiential Education.

    Science.gov (United States)

    Warren, Karen, Ed.

    This book is a collection of feminist analyses of various topics in experiential education, particularly as it applies to outdoors and adventure education, as well as practical examples of how women's experiences can contribute to the field as a whole. Following an introduction, "The Quilt of Women's Voices" (Maya Angelou), the 25…

  14. Cataract Vision Simulator

    Science.gov (United States)

    ... vision. Privacy Policy Related Pet Fish Fitted with Fake Eye in Rare Procedure Jun 30, 2016 Firework ... 28, 2016 Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About the Academy ...

  15. Kids' Quest: Vision Impairment

    Science.gov (United States)

    ... least one other developmental disability, such as intellectual disabilities, cerebral palsy, hearing loss, or epilepsy. Vision impairment is more common in older people than in children. Guide dogs are the guiding ...

  16. Vision and Motion Pictures.

    Science.gov (United States)

    Grambo, Gregory

    1998-01-01

    Presents activities on persistence of vision that involve students in a hands-on approach to the study of early methods of creating motion pictures. Students construct flip books, a Zoetrope, and an early movie machine. (DDR)

  17. Computer Vision Syndrome.

    Science.gov (United States)

    Randolph, Susan A

    2017-07-01

    With the increased use of electronic devices with visual displays, computer vision syndrome is becoming a major public health issue. Improving the visual status of workers using computers results in greater productivity in the workplace and improved visual comfort.

  18. H-infinity control for switched and impulsive singular systems

    Institute of Scientific and Technical Information of China (English)

    Yujuan YIN; Jun ZHAO; Yuzhong LIU

    2008-01-01

    A new model of dynamical systems is proposed which consists of singular systems with impulsive effects, i.e., switched and impulsive singular systems (SISS). By using the switched Lyapunov functions method, a sufficient condition for the solvability of the H-infinity control problem for SISSs is given which generalizes the H-infinity control theory for singular systems to switched singular systems with impulsive effects. Then the sufficient condition of solvablity of the H-infinity control problem is presented in terms of linear matrix inequalities. Finally, the effectiveness of the developed approach for switched and impulsive singular systems is illustrated by a numerical example.

  19. Quantum singularities in static and conformally static space-times

    CERN Document Server

    Konkowski, D A; 10.1142/S0217751X11054334

    2011-01-01

    The definition of quantum singularity is extended from static space-times to conformally static space-times. After the usual definitions of classical and quantum singularities are reviewed, examples of quantum singularities in static space-times are given. These include asymptotically power-law space-times, space-times with diverging higher-order differential invariants, and a space-time with a 2-sphere singularity. The theory behind quantum singularities in conformally static space-times is followed by an example, a Friedmann-Robertson-Walker space-time with cosmic string. The paper concludes by discussing areas of future research.

  20. Singularity theory of fitness functions under dimorphism equivalence.

    Science.gov (United States)

    Wang, Xiaohui; Golubitsky, Martin

    2016-09-01

    We apply singularity theory to classify monomorphic singular points as they occur in adaptive dynamics. Our approach is based on a new equivalence relation called dimorphism equivalence, which is the largest equivalence relation on strategy functions that preserves ESS singularities, CvSS singularities, and dimorphisms. Specifically, we classify singularities up to topological codimension two and compute their normal forms and universal unfoldings. These calculations lead to the classification of local mutual invasibility plots that can be seen generically in systems with two parameters.

  1. The Universality of Penrose Limits near Space-Time Singularities

    CERN Document Server

    Blau, Matthias; O'Loughlin, M; Papadopoulos, G; Blau, Matthias; Borunda, Monica; Loughlin, Martin O'; Papadopoulos, George

    2004-01-01

    We prove that Penrose limits of metrics with arbitrary singularities of power-law type show a universal leading u^{-2}-behaviour near the singularity provided that the dominant energy condition is satisfied and not saturated. For generic power-law singularities of this type the oscillator frequencies of the resulting homogeneous singular plane wave turn out to lie in a range which is known to allow for an analytic extension of string modes through the singularity. The discussion is phrased in terms of the recently obtained covariant characterisation of the Penrose limit; the relation with null geodesic deviation is explained in detail.

  2. Rhetorical Visions of Unmarried Mothers.

    Science.gov (United States)

    Endres, Thomas G.

    1989-01-01

    Examines the symbolic reality of unmarried mothers using Bormann's fantasy theme analysis and Q-methodology. Identifies three rhetorical visions with a dramatistic humanistic analysis produced by and about unmarried mothers: the Down and Out Vision, the Making the Best Vision, and the Yummie Vision. (MS)

  3. Temporal voice areas exist in autism spectrum disorder but are dysfunctional for voice identity recognition

    Science.gov (United States)

    Borowiak, Kamila; von Kriegstein, Katharina

    2016-01-01

    The ability to recognise the identity of others is a key requirement for successful communication. Brain regions that respond selectively to voices exist in humans from early infancy on. Currently, it is unclear whether dysfunction of these voice-sensitive regions can explain voice identity recognition impairments. Here, we used two independent functional magnetic resonance imaging studies to investigate voice processing in a population that has been reported to have no voice-sensitive regions: autism spectrum disorder (ASD). Our results refute the earlier report that individuals with ASD have no responses in voice-sensitive regions: Passive listening to vocal, compared to non-vocal, sounds elicited typical responses in voice-sensitive regions in the high-functioning ASD group and controls. In contrast, the ASD group had a dysfunction in voice-sensitive regions during voice identity but not speech recognition in the right posterior superior temporal sulcus/gyrus (STS/STG)—a region implicated in processing complex spectrotemporal voice features and unfamiliar voices. The right anterior STS/STG correlated with voice identity recognition performance in controls but not in the ASD group. The findings suggest that right STS/STG dysfunction is critical for explaining voice recognition impairments in high-functioning ASD and show that ASD is not characterised by a general lack of voice-sensitive responses. PMID:27369067

  4. Characterizing maximally singular phase-space distributions

    Science.gov (United States)

    Sperling, J.

    2016-07-01

    Phase-space distributions are widely applied in quantum optics to access the nonclassical features of radiations fields. In particular, the inability to interpret the Glauber-Sudarshan distribution in terms of a classical probability density is the fundamental benchmark for quantum light. However, this phase-space distribution cannot be directly reconstructed for arbitrary states, because of its singular behavior. In this work, we perform a characterization of the Glauber-Sudarshan representation in terms of distribution theory. We address important features of such distributions: (i) the maximal degree of their singularities is studied, (ii) the ambiguity of representation is shown, and (iii) their dual space for nonclassicality tests is specified. In this view, we reconsider the methods for regularizing the Glauber-Sudarshan distribution for verifying its nonclassicality. This treatment is supported with comprehensive examples and counterexamples.

  5. Symmetries and singularities of the Szekeres system

    Energy Technology Data Exchange (ETDEWEB)

    Paliathanasis, Andronikos, E-mail: anpaliat@phys.uoa.gr [Instituto de Ciencias Físicas y Matemáticas, Universidad Austral de Chile, Valdivia (Chile); Institute of Systems Science, Durban University of Technology, POB 1334, Durban 4000 (South Africa); Leach, P.G.L., E-mail: leach.peter@ucy.ac.cy [Department of Mathematics and Institute of Systems Science, Research and Postgraduate Support, Durban University of Technology, POB 1334, Durban 4000 (South Africa); School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa)

    2017-04-18

    Highlights: • Lagrangian formalism of the Szekeres system. • Symmetries and conservation laws for the silent universe. • Comparison of stability analysis of special solutions with the Laurent expansion provided by the singularity analysis. - Abstract: The Szekeres system is studied with two methods for the determination of conservation laws. Specifically we apply the theory of group invariant transformations and the method of singularity analysis. We show that the Szekeres system admits a Lagrangian and the conservation laws that we find can be derived by the application of Noether's theorem. The stability for the special solutions of the Szekeres system is studied and it is related with the Left or Right Painlevé Series which describes the expansions.

  6. Vlasov moments, integrable systems and singular solutions

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, John [Department of Mathematics, Imperial College London, London SW7 2AZ (United Kingdom); Holm, Darryl D. [Department of Mathematics, Imperial College London, London SW7 2AZ (United Kingdom); Computer and Computational Science Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)], E-mail: d.holm@ic.ac.uk; Tronci, Cesare [Department of Mathematics, Imperial College London, London SW7 2AZ (United Kingdom); TERA Foundation for Oncological Hadrontherapy, 11 V. Puccini, Novara 28100 (Italy)

    2008-02-11

    The Vlasov equation governs the evolution of the single-particle probability distribution function (PDF) for a system of particles interacting without dissipation. Its singular solutions correspond to the individual particle motions. The operation of taking the moments of the Vlasov equation is a Poisson map. The resulting Lie-Poisson Hamiltonian dynamics of the Vlasov moments is found to be integrable is several cases. For example, the dynamics for coasting beams in particle accelerators is associated by a hodograph transformation to the known integrable Benney shallow-water equation. After setting the context, the Letter focuses on geodesic Vlasov moment equations. Continuum closures of these equations at two different orders are found to be integrable systems whose singular solutions characterize the geodesic motion of the individual particles.

  7. Kerr Naked Singularities as Particle Accelerators

    CERN Document Server

    Patil, Mandar

    2011-01-01

    We investigate here the particle acceleration by Kerr naked singularities. We consider a collision between particles dropped in from infinity at rest, which follow geodesic motion in the equatorial plane, with angular momentum of one of the particles in an appropriate finite range of values. The absence of an event horizon and the repulsive nature of angular momentum makes it possible for the initially infalling particle to turn back as an outgoing particle and then collide with another infalling particle. When these particles collide at a location close to what would have been the event horizon in the extremal Kerr blackhole case, the center of mass energy of collision turns out to be arbitrarily large depending on how close is the Kerr naked singularity to extremality. We briefly discuss the possible astrophysical consequences of this process and suggest that the fast rotating Kerr configurations could provide a good cosmic laboratory to probe ultra-high-energy physics.

  8. Complex-temperature singularities of Ising models

    CERN Document Server

    Shrock, R E

    1995-01-01

    We report new results on complex-temperature properties of Ising models. These include studies of the s=1/2 model on triangular, honeycomb, kagom\\'e, 3 \\cdot 12^2, and 4 \\cdot 8^2 lattices. We elucidate the complex--T phase diagrams of the higher-spin 2D Ising models, using calculations of partition function zeros. Finally, we investigate the 2D Ising model in an external magnetic field, mapping the complex--T phase diagram and exploring various singularities therein. For the case \\beta H=i\\pi/2, we give exact results on the phase diagram and obtain susceptibility exponents \\gamma' at various singularities from low-temperature series analyses.

  9. Singular electrostatic energy of nanoparticle clusters

    Science.gov (United States)

    Qin, Jian; Krapf, Nathan W.; Witten, Thomas A.

    2016-02-01

    The binding of clusters of metal nanoparticles is partly electrostatic. We address difficulties in calculating the electrostatic energy when high charging energies limit the total charge to a single quantum, entailing unequal potentials on the particles. We show that the energy at small separation h has a singular logarithmic dependence on h . We derive a general form for this energy in terms of the singular capacitance of two spheres in near contact c (h ) , together with nonsingular geometric features of the cluster. Using this form, we determine the energies of various clusters, finding that more compact clusters are more stable. These energies are proposed to be significant for metal-semiconductor binary nanoparticle lattices found experimentally. We sketch how these effects should dictate the relative abundances of metal nanoparticle clusters in nonpolar solvents.

  10. Biofeedback for Better Vision

    Science.gov (United States)

    1990-01-01

    Biofeedtrac, Inc.'s Accommotrac Vision Trainer, invented by Dr. Joseph Trachtman, is based on vision research performed by Ames Research Center and a special optometer developed for the Ames program by Stanford Research Institute. In the United States, about 150 million people are myopes (nearsighted), who tend to overfocus when they look at distant objects causing blurry distant vision, or hyperopes (farsighted), whose vision blurs when they look at close objects because they tend to underfocus. The Accommotrac system is an optical/electronic system used by a doctor as an aid in teaching a patient how to contract and relax the ciliary body, the focusing muscle. The key is biofeedback, wherein the patient learns to control a bodily process or function he is not normally aware of. Trachtman claims a 90 percent success rate for correcting, improving or stopping focusing problems. The Vision Trainer has also proved effective in treating other eye problems such as eye oscillation, cross eyes, and lazy eye and in professional sports to improve athletes' peripheral vision and reaction time.

  11. Algebraic Bethe ansatz for a singular solution

    CERN Document Server

    Nepomechie, Rafael I

    2013-01-01

    The Bethe equations for the spin-1/2 Heisenberg chain with N sites have a "two-string" solution i/2, -i/2 that is singular: both the corresponding energy and algebraic Bethe ansatz vector are divergent. We show that this solution must be carefully regularized in order to obtain the correct eigenvector. This regularization involves a parameter that can be determined using a generalization of the Bethe equations. It follows that this solution must be excluded for odd N.

  12. Symplectic surgeries and normal surface singularities

    OpenAIRE

    Gay, David T.; Stipsicz, Andras I.

    2007-01-01

    We show that every negative definite configuration of symplectic surfaces in a symplectic 4--manifold has a strongly symplectically convex neighborhood. We use this to show that, if a negative definite configuration satisfies an additional negativity condition at each surface in the configuration, and if the complex singularity with resolution diffeomorphic to a neighborhood of the configuration has a smoothing, then the configuration can be symplectically replaced by the smoothing of the sin...

  13. Macdonald formula for curves with planar singularities

    CERN Document Server

    Maulik, Davesh

    2011-01-01

    We generalize Macdonald's formula for the cohomology of Hilbert schemes of points on a curve from smooth curves to curves with planar singularities: we relate the cohomology of the Hilbert schemes to the cohomology of the compactified Jacobian of the curve. The new formula is a consequence of a stronger identity between certain perverse sheaves defined by a family of curves satisfying mild conditions, whose proof makes an essential use of Ng\\^o's support theorem for compactified Jacobians.

  14. Singularity theory for W-algebra potentials

    CERN Document Server

    Gaite, J C

    1993-01-01

    The Landau potentials of $W_3$-algebra models are analyzed with algebraic-geometric methods. The number of ground states and the number of independent perturbations of every potential coincide and can be computed. This number agrees with the structure of ground states obtained in a previous paper, namely, as the phase structure of the IRF models of Jimbo et al. The singularities associated to these potentials are identified.

  15. INVERSE SCATTERING PROBLEMS BY SINGULAR SOURCE METHODS

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The inverse scattering problems are to detect the property of obstacles from the measurements outside the obstacles. One of important research areas in this topic is the recovery of boundary property for impenetrable obstacles. In this paper, we would like to give a brief review about the recently developed singular source methods. There are three different methods in this category, namely, linear sampling method, pointsource method and probe method. We also present some recent new results about the probe method.

  16. Space-time singularities in Weyl manifolds

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, I.P. [CAPES Foundation, Ministry of Education of Brazil, Brasilia (Brazil); Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Barreto, A.B.; Romero, C. [Universidade Federal da Paraiba, Departamento de Fisica, C. Postal 5008, Joao Pessoa, PB (Brazil)

    2015-09-15

    We extend one of the Hawking-Penrose singularity theorems in general relativity to the case of some scalar-tensor gravity theories in which the scalar field has a geometrical character and space-time has the mathematical structure of a Weyl integrable space-time. We adopt an invariant formalism, so that the extended version of the theorem does not depend on a particular frame. (orig.)

  17. Superlinear singular fractional boundary-value problems

    Directory of Open Access Journals (Sweden)

    Imed Bachar

    2016-04-01

    Full Text Available In this article, we study the superlinear fractional boundary-value problem $$\\displaylines{ D^{\\alpha }u(x =u(xg(x,u(x,\\quad 00$. The function $g(x,u\\in C((0,1\\times [ 0,\\infty ,[0,\\infty$ that may be singular at x=0 and x=1 is required to satisfy convenient hypotheses to be stated later.

  18. Evaluation of Fifth Degree Elliptic Singular Moduli

    CERN Document Server

    Bagis, Nikos

    2012-01-01

    Our main result in this article is a formula for the extraction of the solution of the fifth degree modular polynomial equation i.e. the value of $k_{25^nr_0}$, when we know only two consecutive values $k_{r_0}$ and $k_{r_0/25}$. By this way we reduce the problem of solving the depressed equation if we known two consecutive values of the Elliptic singular moduli $k_r$.

  19. Singularities in big-bang cosmology

    Science.gov (United States)

    Penrose, R.

    1988-03-01

    A review of the history of the development of the big bang theory is presented, including the nature of singularities in black holes and their contribution to the study of the origin of the universe. Various models of the origin of the universe, the question of cosmic censorship, and the possible effects of gravitational collapse are examined. The relationship between considerations of quantum gravity and the structure of quantum theory is discussed.

  20. Presence is not always in the Singular

    DEFF Research Database (Denmark)

    Nortvig, Anne-Mette

    Teaching in the virtual classroom often involves dichotomies time (synchronous - asynchronous) and space (same place - different places) but when e-learning involves a hybrid mix of students on campus and e-students on-line and the teaching is recorded in order to be watched by other students lat...... of a presence that is not only physical and singular but also very often virtual and plural....

  1. Critical singular problems on unbounded domains

    Directory of Open Access Journals (Sweden)

    D. C. de Morais Filho

    2005-01-01

    Full Text Available We present some results of existence for the following problem: −Δu=a(xg(u+u|u|2∗−2, x∈ℝN(N≥3, u∈D1,2(ℝN, where the function a is a sign-changing function with a singularity at the origin and g has growth up to the Sobolev critical exponent 2∗=2N/(N−2.

  2. On Phases of Generic Toric Singularities

    CERN Document Server

    Sarkar, Tapobrata

    2007-01-01

    We systematically study the phases of generic toric singularities, using methods initiated in hep-th/0612046. These correspond to Gauged Linear Sigma Models with arbitrary charges. We show that complete information about generic $U(1)^r$ GLSMs can be obtained by studying the GLSM Lagrangian, appropriately modified in the different phases of the theory. This can be used to study the different phases of $L^{a,b,c}$ spaces and their non-supersymmetric counterparts.

  3. Selfadjoint extensions of multipoint singular differential operators

    Directory of Open Access Journals (Sweden)

    Zameddin I. Ismailov

    2013-10-01

    Full Text Available This article describes all selfadjoint extensions of the minimal operator generated by a linear singular multipoint symmetric differential-operator expression for first order in the direct sum of Hilbert spaces of vector-functions. This description is done in terms of the boundary values, and it uses the Everitt-Zettl and the Calkin-Gorbachuk methods. Also the structure of the spectrum of these extensions is studied.

  4. Hardware Implementation of Singular Value Decomposition

    Science.gov (United States)

    Majumder, Swanirbhar; Shaw, Anil Kumar; Sarkar, Subir Kumar

    2016-06-01

    Singular value decomposition (SVD) is a useful decomposition technique which has important role in various engineering fields such as image compression, watermarking, signal processing, and numerous others. SVD does not involve convolution operation, which make it more suitable for hardware implementation, unlike the most popular transforms. This paper reviews the various methods of hardware implementation for SVD computation. This paper also studies the time complexity and hardware complexity in various methods of SVD computation.

  5. Singular inflation from generalized equation of state fluids

    Directory of Open Access Journals (Sweden)

    S. Nojiri

    2015-07-01

    Full Text Available We study models with a generalized inhomogeneous equation of state fluids, in the context of singular inflation, focusing to so-called Type IV singular evolution. In the simplest case, this cosmological fluid is described by an equation of state with constant w, and therefore a direct modification of this constant w fluid is achieved by using a generalized form of an equation of state. We investigate from which models with generalized phenomenological equation of state, a Type IV singular inflation can be generated and what the phenomenological implications of this singularity would be. We support our results with illustrative examples and we also study the impact of the Type IV singularities on the slow-roll parameters and on the observational inflationary indices, showing the consistency with Planck mission results. The unification of singular inflation with singular dark energy era for specific generalized fluids is also proposed.

  6. Singular inflation from generalized equation of state fluids

    Energy Technology Data Exchange (ETDEWEB)

    Nojiri, S., E-mail: nojiri@gravity.phys.nagoya-u.ac.jp [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Odintsov, S.D., E-mail: odintsov@ieec.uab.es [Institut de Ciencies de lEspai (IEEC-CSIC), Campus UAB, Carrer de Can Magrans, s/n, 08193 Cerdanyola del Valles, Barcelona (Spain); ICREA, Passeig Lluîs Companys, 23, 08010 Barcelona (Spain); National Research Tomsk State University, 634050 Tomsk (Russian Federation); Tomsk State Pedagogical University, 634061 Tomsk (Russian Federation); Oikonomou, V.K., E-mail: v.k.oikonomou1979@gmail.com [Department of Theoretical Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); National Research Tomsk State University, 634050 Tomsk (Russian Federation); Tomsk State Pedagogical University, 634061 Tomsk (Russian Federation)

    2015-07-30

    We study models with a generalized inhomogeneous equation of state fluids, in the context of singular inflation, focusing to so-called Type IV singular evolution. In the simplest case, this cosmological fluid is described by an equation of state with constant w, and therefore a direct modification of this constant w fluid is achieved by using a generalized form of an equation of state. We investigate from which models with generalized phenomenological equation of state, a Type IV singular inflation can be generated and what the phenomenological implications of this singularity would be. We support our results with illustrative examples and we also study the impact of the Type IV singularities on the slow-roll parameters and on the observational inflationary indices, showing the consistency with Planck mission results. The unification of singular inflation with singular dark energy era for specific generalized fluids is also proposed.

  7. A Game for the Resolution of Singularities

    CERN Document Server

    Hauser, Herwig

    2010-01-01

    We propose a combinatorial game on finite graphs, called Salmagundy, that is played by two protagonists, Dido and Mephisto. The game captures the logical structure of a proof of the resolution of singularities. In each round, the graph of the game is modified by the moves of the players. When it assumes a final configuration, Dido has won. Otherwise, the game goes on forever, and nobody wins. In particular, Mephisto cannot win himself, he can only prevent Dido from winning. We show that Dido always possesses a winning strategy, regardless of the initial shape of the graph and of the moves of Mephisto. This implies -- translating back to algebraic geometry -- that there is a choice of centers for the blowup of singular varieties in characteristic zero which eventually leads to their resolution. The algebra needed for this implication is elementary. The transcription from varieties to graphs and from blowups to modifications of the graph thus axiomatizes the proof of the resolution of singularities. In principl...

  8. Spectral asymptotics for nonsmooth singular Green operators

    DEFF Research Database (Denmark)

    Grubb, Gerd

    2014-01-01

    Singular Green operators G appear typically as boundary correction terms in resolvents for elliptic boundary value problems on a domain Ω ⊂ ℝ n , and more generally they appear in the calculus of pseudodifferential boundary problems. In particular, the boundary term in a Krein resolvent formula...... is a singular Green operator. It is well-known in smooth cases that when G is of negative order −t on a bounded domain, its eigenvalues ors-numbers have the behavior (*)s j (G) ∼ cj −t/(n−1) for j → ∞, governed by the boundary dimension n − 1. In some nonsmooth cases, upper estimates (**)s j (G) ≤ Cj −t/(n−1......) are known. We show that (*) holds when G is a general selfadjoint nonnegative singular Green operator with symbol merely Hölder continuous in x. We also show (*) with t = 2 for the boundary term in the Krein resolvent formula comparing the Dirichlet and a Neumann-type problem for a strongly elliptic...

  9. Indeterministic Quantum Gravity and Cosmology; 7, Dynamical Passage through Singularities Black Hole and Naked Singularity, Big Crunch and Big Bang

    CERN Document Server

    Mashkevich, V S

    1997-01-01

    This paper is a continuation of the papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035, gr-qc/9609046, gr-qc/9704033]. The aim of the paper is to incorporate singularities---both local (black hole and naked singularity) and global (big bang and big crunch)---into the dynamics of indeterministic quantum gravity and cosmology. The question is whether a singularity is dynamically passable, i.e., whether a dynamical process which ends with a singularity may be extended beyond the latter. The answer is yes. A local singularity is trivially passable, while the passableness for a global singularity may invoke CPT transformation. The passableness of the singularities implies pulsating black holes and the oscillating universe. For the local singularity, the escape effect takes place: In a vicinity of the singularity, quantum matter leaves the gravitational potential well. Keywords: tempered singularity, strong singularity, trivial passage, CPT passage, pulsating black hole, escape effect, oscillating u...

  10. Comparing acoustic and perceptual voice parameters in female teachers based on voice complaints

    Directory of Open Access Journals (Sweden)

    Maryam Faghani Abukeili

    2014-04-01

    Full Text Available Background and Aim: Teachers are a large group of professional voice users that several risk factors and voice demands causes various voice complaints among them. As the voice is multidimensional, the aim of this study was acoustic and perceptual measurement of teachers’ voice and comparing the findings between two groups with many and few voice complaints.Methods: Sixty female teachers of high school in Sari, north of Iran, were chosen by available sampling to participate in this cross-sectional study. According to a voice complaints questionnaire, 21 subjects located in few voice complaints and 31 in many voice complaints group. After a working day, subjects completed a voice self-assessment questionnaire. Also, teachers’voice were recorded during three tasks including sustained vowels /a/ and /i/, text reading and conversational speech. Acoustic parameters were analyzed by Praat software and 2 speech-language pathalogists performed auditory-perceptual assessment by GRBAS ( Grade, Roughness, Breathiness, Asthenia, Strain scale. Results: Comparing of the voice self-assessment between the two groups demonstrated statistically significant difference (p<0.05; however results of the acoustic and auditory-perceptual measurement did not show significant diffrence.Conclusion: Despite prevalent voice problems in teachers, there are various conditions in terms of complaints and assessments methods. In this study, only a remarkable deviation documented in the client-based assessments in many voice compliants group in comparison with few voice compliants, which would be probably related to different individual’s perception of voice problem between two groups. These results support paying attention to self-assessments in clinical process of voice problems.

  11. The Role of Occupational Voice Demand and Patient-Rated Impairment in Predicting Voice Therapy Adherence.

    Science.gov (United States)

    Ebersole, Barbara; Soni, Resha S; Moran, Kathleen; Lango, Miriam; Devarajan, Karthik; Jamal, Nausheen

    2017-07-11

    Examine the relationship among the severity of patient-perceived voice impairment, perceptual dysphonia severity, occupational voice demand, and voice therapy adherence. Identify clinical predictors of increased risk for therapy nonadherence. A retrospective cohort study of patients presenting with a chief complaint of persistent dysphonia at an interdisciplinary voice center was done. The Voice Handicap Index-10 (VHI-10) and the Voice-Related Quality of Life (V-RQOL) survey scores, clinician rating of dysphonia severity using the Grade score from the Grade, Roughness Breathiness, Asthenia, and Strain scale, occupational voice demand, and patient demographics were tested for associations with therapy adherence, defined as completion of the treatment plan. Classification and Regression Tree (CART) analysis was performed to establish thresholds for nonadherence risk. Of 166 patients evaluated, 111 were recommended for voice therapy. The therapy nonadherence rate was 56%. Occupational voice demand category, VHI-10, and V-RQOL scores were the only factors significantly correlated with therapy adherence (P occupational voice demand are significantly more likely to be nonadherent with therapy than those with high occupational voice demand (P 40 is a significant cutoff point for predicting therapy nonadherence (P Occupational voice demand and patient perception of impairment are significantly and independently correlated with therapy adherence. A VHI-10 score of ≤9 or a V-RQOL score of >40 is a significant cutoff point for predicting nonadherence risk. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  12. Nonlinear singularly perturbed optimal control problems with singular arcs. [flight mechanics application

    Science.gov (United States)

    Ardema, M. D.

    1979-01-01

    Singular perturbation techniques are studied for dealing with singular arc problems by analyzing a relatively low-order but otherwise general system. This system encompasses many flight mechanic problems including Goddard's problem and a version of the minimum time-to-climb problem. Boundary layer solutions are constructed which are stable and reach the outer solution in a finite time. A uniformly valid composite solution is then formed from the reduced and boundary layer solutions. The value of the approximate solution is that it is relatively easy to obtain and does not involve singular arcs. To illustrate the utility of the results, the technique is used to obtain an approximate solution of a simplified version of the aircraft minimum time-to-climb problem.

  13. Effects of Finite-time Singularities on Gravitational Waves

    CERN Document Server

    Kleidis, K

    2016-01-01

    We analyze the impact of finite-time singularities on gravitational waves, in the context of $F(R)$ gravity. We investigate which singularities are allowed to occur during the inflationary era, when gravitational waves are considered, and we discuss the quantitative implications of each allowed singularity. As we show, only a pressure singularity, the so-called Type II and also a Type IV singularity are allowed to occur during the inflationary era. In the case of a Type II, the resulting amplitude of the gravitational wave is zero or almost zero, hence this pressure singularity has a significant impact on the primordial gravitational waves. The case of a Type IV singularity is more interesting since as we show, the singularity has no effect on the amplitude of the gravitational waves. Therefore, this result combined with the fact that the Type IV singularity affects only the dynamics of inflation, leads to the conclusion that the Universe passes smoothly through a Type IV singularity.

  14. Insect vision as model for machine vision

    Science.gov (United States)

    Osorio, D.; Sobey, Peter J.

    1992-11-01

    The neural architecture, neurophysiology and behavioral abilities of insect vision are described, and compared with that of mammals. Insects have a hardwired neural architecture of highly differentiated neurons, quite different from the cerebral cortex, yet their behavioral abilities are in important respects similar to those of mammals. These observations challenge the view that the key to the power of biological neural computation is distributed processing by a plastic, highly interconnected, network of individually undifferentiated and unreliable neurons that has been a dominant picture of biological computation since Pitts and McCulloch's seminal work in the 1940's.

  15. IDA's Energy Vision 2050

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Hansen, Kenneth

    IDA’s Energy Vision 2050 provides a Smart Energy System strategy for a 100% renewable Denmark in 2050. The vision presented should not be regarded as the only option in 2050 but as one scenario out of several possibilities. With this vision the Danish Society of Engineers, IDA, presents its third......-of-the-art knowledge about how low cost energy systems can be designed while also focusing on long-term resource efficiency. The Energy Vision 2050 has the ambition to focus on all parts of the energy system rather than single technologies, but to have an approach in which all sectors are integrated. While Denmark...... contribution for an energy strategy for Denmark. The IDA’s Energy Plan 2030 was prepared in 2006 and IDA’s Climate Plan was prepared in 2009. IDA’s Energy Vision 2050 is developed for IDA by representatives from The Society of Engineers and by a group of researchers at Aalborg University. It is based on state...

  16. IDA's Energy Vision 2050

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Hansen, Kenneth

    IDA’s Energy Vision 2050 provides a Smart Energy System strategy for a 100% renewable Denmark in 2050. The vision presented should not be regarded as the only option in 2050 but as one scenario out of several possibilities. With this vision the Danish Society of Engineers, IDA, presents its third...... contribution for an energy strategy for Denmark. The IDA’s Energy Plan 2030 was prepared in 2006 and IDA’s Climate Plan was prepared in 2009. IDA’s Energy Vision 2050 is developed for IDA by representatives from The Society of Engineers and by a group of researchers at Aalborg University. It is based on state......-of-the-art knowledge about how low cost energy systems can be designed while also focusing on long-term resource efficiency. The Energy Vision 2050 has the ambition to focus on all parts of the energy system rather than single technologies, but to have an approach in which all sectors are integrated. While Denmark...

  17. Colour, vision and ergonomics.

    Science.gov (United States)

    Pinheiro, Cristina; da Silva, Fernando Moreira

    2012-01-01

    This paper is based on a research project - Visual Communication and Inclusive Design-Colour, Legibility and Aged Vision, developed at the Faculty of Architecture of Lisbon. The research has the aim of determining specific design principles to be applied to visual communication design (printed) objects, in order to be easily read and perceived by all. This study target group was composed by a selection of socially active individuals, between 55 and 80 years, and we used cultural events posters as objects of study and observation. The main objective is to overlap the study of areas such as colour, vision, older people's colour vision, ergonomics, chromatic contrasts, typography and legibility. In the end we will produce a manual with guidelines and information to apply scientific knowledge into the communication design projectual practice. Within the normal aging process, visual functions gradually decline; the quality of vision worsens, colour vision and contrast sensitivity are also affected. As people's needs change along with age, design should help people and communities, and improve life quality in the present. Applying principles of visually accessible design and ergonomics, the printed design objects, (or interior spaces, urban environments, products, signage and all kinds of visually information) will be effective, easier on everyone's eyes not only for visually impaired people but also for all of us as we age.

  18. Perturbation Measures of Voice: A Comparative Study between Multi-Dimensional Voice Program and Praat

    National Research Council Canada - National Science Library

    Maryn, Youri; Corthals, Paul; De Bodt, Marc; Van Cauwenberge, Paul; Deliyski, Dimitar

    2009-01-01

    .... In the present study, perturbation measures provided by two computer systems (a purpose-built professional voice analysis apparatus and a personal computer-based system for acoustic voice assessment...

  19. [The smokers voice self assessment based on Voice Handicap Index (VHI)].

    Science.gov (United States)

    Wiskirska-Woźnica, Bozena; Wojnowski, Waldemar

    2009-01-01

    Complex voice assessment due to European Laryngeal Society proposals (2000) contains voice self estimation based on the Polish version of the Voice Handicap Index (VHI). This study focuses on the relation between voice handicap and smoking in dysphonic patients, who are using voice professionally. Thirty outpatient (25 female and 5 male, aged 40 to 55 years) voice department attendees suffering from professional dysphonia took part in this study. All patients after phoniatric examination completed the Polish version of the Voice Handicap Index (VHI). The questions concern functional, emotional and physical complains due to dysphonia. Most of smokers did not complain of dysphonia related problems comparing to non smokers. Even the scores of functional and emotional scales of VHI in smokers shown better results (less handicap) than in nonsmokers. Smoking does not affect patients handicap due to dysphonia measured in the Voice Handicap Index.

  20. Qos and Voice Over IP

    Directory of Open Access Journals (Sweden)

    Adrian GHENCEA

    Full Text Available As Voice over Internet Protocol (VoIP technology matures, companies are increasingly adopting it to cut costs, improve efficiency and enhance customer service. Using the Internet as an existing network for integrating data and telecom systems through intelligent VoIP, a range of benefits results: lower long distance costs, cost cuts in cabling processes and more flexible telephony management. However, as voice over IP services grow in popularity, major threats arise: this rapid growth leads to traffic congestion, security is jeopardizedand the poor quality of calls affects communication. The objective of this article is to present all the elements that can affect voicequality in a VoIP network and to provide methods for solving them. A detailed analysis to minimize the impact of implementation of QoS will be made, and at the end solutions to management strategies will be proposed.