Methods for the identification of material parameters in distributed models for flexible structures

Theoretical and numerical results are presented for inverse problems involving estimation of spatially varying parameters such as stiffness and damping in distributed models for elastic structures such as Euler-Bernoulli beams. An outline of algorithms used and a summary of computational experiences are presented

On a generalized quantum SWAP gate

The SWAP gate plays a central role in network designs for qubit quantum computation. However, there has been a view to generalize qubit quantum computing to higher dimensional quantum systems. In this paper we construct a generalized SWAP gate using only instances of the generalized controlled-NOT gate to cyclically permute the states of d qudits for d prime

ORFEUS II and IUE Spectroscopy of EX Hydrae

Using ORFEUS-SPAS II FUV spectra, IUE UV spectra, and archival EUVE deep survey photometry, we present a detailed picture of the behavior of the magnetic cataclysmic variable EX Hydrae. Like HUT spectra of this source, the FUV and UV spectra reveal broad emission lines of He II, C II-IV, N III and V, O VI, Si III-IV, and Al III superposed on a continuum which is blue in the UV and nearly flat in the FUV. Like ORFEUS spectra of AM Her, the O VI doublet is resolved into broad and narrow emission components. Consistent with its behavior in the optical, the FUV and UV continuum flux densities, the FUV and UV broad emission line fluxes, and the radial velocity of the O VI broad emission component all vary on the spin phase of the white dwarf, with the maximum of the FUV and UV continuum and broad emission line flux light curves coincident with maximum blueshift of the broad O VI emission component. On the binary phase, the broad dip in the EUV light curve is accompanied by strong eclipses of the UV emission lines and by variations in both the flux and radial velocity of the O VI narrow emission component. The available data are consistent with the accretion funnel being the source of the FUV and UV continuum and the O VI broad emission component, and the white dwarf being the source of the O VI narrow emission component.Comment: 21 pages, 10 Postscript figures; LaTeX format, uses aaspp4.sty; table2.tex included separately because it must be printed sideways - see instructions in the file; accepted on 1999 Feb 20 for publication in The Astrophysical Journa

Geodetic, teleseismic, and strong motion constraints on slip from recent southern Peru subduction zone earthquakes

We use seismic and geodetic data both jointly and separately to constrain coseismic slip from the 12 November 1996 M_w 7.7 and 23 June 2001 M_w 8.5 southern Peru subduction zone earthquakes, as well as two large aftershocks following the 2001 earthquake on 26 June and 7 July 2001. We use all available data in our inversions: GPS, interferometric synthetic aperture radar (InSAR) from the ERS-1, ERS-2, JERS, and RADARSAT-1 satellites, and seismic data from teleseismic and strong motion stations. Our two-dimensional slip models derived from only teleseismic body waves from South American subduction zone earthquakes with M_w > 7.5 do not reliably predict available geodetic data. In particular, we find significant differences in the distribution of slip for the 2001 earthquake from models that use only seismic (teleseismic and two strong motion stations) or geodetic (InSAR and GPS) data. The differences might be related to postseismic deformation or, more likely, the different sensitivities of the teleseismic and geodetic data to coseismic rupture properties. The earthquakes studied here follow the pattern of earthquake directivity along the coast of western South America, north of 5°S, earthquakes rupture to the north; south of about 12°S, directivity is southerly; and in between, earthquakes are bilateral. The predicted deformation at the Arequipa GPS station from the seismic-only slip model for the 7 July 2001 aftershock is not consistent with significant preseismic motion

Interstitial gas and density-segregation in vertically-vibrated granular media

We report experimental studies of the effect of interstitial gas on mass-density-segregation in a vertically-vibrated mixture of equal-sized bronze and glass spheres. Sufficiently strong vibration in the presence of interstitial gas induces vertical segregation into sharply separated bronze and glass layers. We find that the segregated steady state (i.e., bronze or glass layer on top) is a sensitive function of gas pressure and viscosity, as well as vibration frequency and amplitude. In particular, we identify distinct regimes of behavior that characterize the change from bronze-on-top to glass-on-top steady-state.Comment: 4 pages, 5 figures, submitted to PRL; accepted in PRE as rapid communication, with revised text and reference

MSW-like Enhancements without Matter

We study the effects of a scalar field, coupled only to neutrinos, on oscillations among weak interaction current eigenstates. The effect of a real scalar field appears as effective masses for the neutrino mass eigenstates, the same for \nbar as for \n. Under some conditions, this can lead to a vanishing of $\delta m^2$, giving rise to MSW-like effects. We discuss some examples and show that it is possible to resolve the apparent discrepancy in spectra required by r-process nucleosynthesis in the mantles of supernovae and by Solar neutrino solutions.Comment: 9 pages, latex, 1 figur

Attorney-Client Confidentiality and the Assessment of Claimants Who Allege Posttraumatic Stress Disorder

Posttraumatic Stress Disorder (PTSD) was first recognized by the American Psychiatric Association in 1980. A PTSD diagnosis requires an individual or individual\u27s loved ones to have experienced a traumatic event that was a threat to life or physical integrity and caused the individual to react to the incident with a specific number of avoidance, reexperiencing, and hyper-arousal symptoms. Obtaining a PTSD diagnosis can be of great value to a personal-injury plaintiff who claims damages due to a traumatic event. Further, if the traumatic event is unquestioned and the individual reports the classic symptoms, a PTSD diagnosis is relatively easy to apply and difficult to disprove. These plaintiffs will most often be examined and evaluated by mental-health professionals retained by the defendants. The question of whether the claimant was told or provided materials about common PTSD symptoms is crucial to the defense evaluator\u27s accurate PTSD assessment. One source of such information would be plaintiffs counsel, but questions concerning information provided by counsel implicate the attorney-client privilege. This Article suggests that the policy bases underlying the attorney-client privilege and protecting a defendant\u27s right to test the validity of a plaintiff\u27s claims are best served by the creation of a narrowly drawn waiver or exception to the attorney-client privilege. Consistent with the patient-litigant exception to the physician-patient privilege, the proposed exception would be limited to those matters directly related to the nature, diagnosis, and symptoms of PTSD placed in issue by the plaintiff. The exception would also be limited to statements and materials about PTSD symptoms the attorney provided the client. This Article also notes the difficult ethical boundary between an attorney providing essential advice to a client about the nature of emotional and psychological damages versus improper coaching. The proposed exception would help discourage improper coaching and lead to the discovery of any improper coaching that had already occurred. Even where the information provided by the attorney was appropriate from an ethical standpoint, discovery of that information is essential to an accurate diagnosis and fairness to defendants

Calculation of some determinants using the s-shifted factorial

Several determinants with gamma functions as elements are evaluated. This kind of determinants are encountered in the computation of the probability density of the determinant of random matrices. The s-shifted factorial is defined as a generalization for non-negative integers of the power function, the rising factorial (or Pochammer's symbol) and the falling factorial. It is a special case of polynomial sequence of the binomial type studied in combinatorics theory. In terms of the gamma function, an extension is defined for negative integers and even complex values. Properties, mainly composition laws and binomial formulae, are given. They are used to evaluate families of generalized Vandermonde determinants with s-shifted factorials as elements, instead of power functions.Comment: 25 pages; added section 5 for some examples of application

Attorney-Client Confidentiality and the Assessment of Claimants Who Allege Posttraumatic Stress Disorder

Posttraumatic Stress Disorder (PTSD) was first recognized by the American Psychiatric Association in 1980. A PTSD diagnosis requires an individual or individual\u27s loved ones to have experienced a traumatic event that was a threat to life or physical integrity and caused the individual to react to the incident with a specific number of avoidance, reexperiencing, and hyper-arousal symptoms. Obtaining a PTSD diagnosis can be of great value to a personal-injury plaintiff who claims damages due to a traumatic event. Further, if the traumatic event is unquestioned and the individual reports the classic symptoms, a PTSD diagnosis is relatively easy to apply and difficult to disprove. These plaintiffs will most often be examined and evaluated by mental-health professionals retained by the defendants. The question of whether the claimant was told or provided materials about common PTSD symptoms is crucial to the defense evaluator\u27s accurate PTSD assessment. One source of such information would be plaintiffs counsel, but questions concerning information provided by counsel implicate the attorney-client privilege. This Article suggests that the policy bases underlying the attorney-client privilege and protecting a defendant\u27s right to test the validity of a plaintiff\u27s claims are best served by the creation of a narrowly drawn waiver or exception to the attorney-client privilege. Consistent with the patient-litigant exception to the physician-patient privilege, the proposed exception would be limited to those matters directly related to the nature, diagnosis, and symptoms of PTSD placed in issue by the plaintiff. The exception would also be limited to statements and materials about PTSD symptoms the attorney provided the client. This Article also notes the difficult ethical boundary between an attorney providing essential advice to a client about the nature of emotional and psychological damages versus improper coaching. The proposed exception would help discourage improper coaching and lead to the discovery of any improper coaching that had already occurred. Even where the information provided by the attorney was appropriate from an ethical standpoint, discovery of that information is essential to an accurate diagnosis and fairness to defendants