1,444 research outputs found
Shape invariant hypergeometric type operators with application to quantum mechanics
A hypergeometric type equation satisfying certain conditions defines either a
finite or an infinite system of orthogonal polynomials. The associated special
functions are eigenfunctions of some shape invariant operators. These operators
can be analysed together and the mathematical formalism we use can be extended
in order to define other shape invariant operators. All the considered shape
invariant operators are directly related to Schrodinger type equations.Comment: More applications available at http://fpcm5.fizica.unibuc.ro/~ncotfa
Non-western celebrity politics and diplomacy: introduction
The origins of the specific project featured in this Cultural Report lie in a larger scale project funded by the Arts and Humanities Research Council and based at the White Rose East Asia Centre at the Universities of Leeds and Sheffield. The project set out to explore the influence and roles of a range of informal political actors such as former leaders, political spouses and 10 celebrity diplomats, to name but a few, across both the domestic and international levels of analysis in three regions of the world: East Asia, Russia and the Arab World
Gazeau-Klauder type coherent states for hypergeometric type operators
The hypergeometric type operators are shape invariant, and a factorization
into a product of first order differential operators can be explicitly
described in the general case. Some additional shape invariant operators
depending on several parameters are defined in a natural way by starting from
this general factorization. The mathematical properties of the eigenfunctions
and eigenvalues of the operators thus obtained depend on the values of the
involved parameters. We study the parameter dependence of orthogonality, square
integrability and of the monotony of eigenvalue sequence. The obtained results
allow us to define certain systems of Gazeau-Klauder coherent states and to
describe some of their properties. Our systematic study recovers a number of
well-known results in a natural unified way and also leads to new findings.Comment: An error occurring in Theorem 12 and Theorem 13 has been correcte
Shape Invariant Potential and Semi-Unitary Transformations (SUT) for Supersymmetric Harmonic Oscillator in T4-Space
Constructing the Semi - Unitary Transformation (SUT) to obtain the
supersymmetric partner Hamiltonians for a one dimensional harmonic oscillator,
it has been shown that under this transformation the supersymmetric partner
loses its ground state in T^{4}- space while its eigen functions constitute a
complete orthonormal basis in a subspace of full Hilbert space.
Keywords: Supersymmetry, Superluminal Transformations, Semi Unitary
Transformations.
PACS No: 14.80L
General Relativistic Mean Field Theory for Rotating Nuclei
We formulate a general relativistic mean field theory for rotating nuclei
starting from the special relativistic model Lagrangian. The
tetrad formalism is adopted to generalize the model to the accelerated frame.Comment: 13 pages, REVTeX, no figures, submitted to Phys. Rev. Lett., the word
`curved' is replaced by `non-inertial' or `accelerated' in several places to
clarify the physical situation interested, some references are added, more
detail discussions are given with omitting some redundant sentence
True Superconductivity in a 2D "Superconducting-Insulating" System
We present results on disordered amorphous films which are expected to
undergo a field-tuned Superconductor-Insulator Transition. Based on low-field
data and I-V characteristics, we find evidence of a low temperature
Metal-to-Superconductor transition. This transition is characterized by
hysteretic magnetoresistance and discontinuities in the I-V curves. The
metallic phase just above the transition is different from the "Fermi Metal"
before superconductivity sets in.Comment: 3 pages, 4 figure
Human papillomavirus and abnormal cervical lesions among HIV-infected women in HIV-discordant couples from Kenya
Objective HIV infection increases the risk of high-grade cervical neoplasia and invasive cervical carcinoma. The study addresses the limited data describing human papillomavirus (HPV) infection and cervical neoplasia among HIV-infected women in HIV-discordant relationships in sub-Saharan Africa, which is needed to inform screening strategies. Methods A cross-sectional study of HIV-infected women with HIV-uninfected partners was conducted to determine the distribution of type-specific HPV infection and cervical cytology. This study was nested in a prospective cohort recruited between September 2007 and December 2009 in Nairobi, Kenya. Cervical cells for HPV DNA testing and conventional cervical cytology were collected. HPV types were detected and genotyped by Roche Linear Array PCR assay. Results Among 283 women, the overall HPV prevalence was 62%, and 132 (47%) had â„1 high-risk (HR)-HPV genotype. Of 268 women with cervical cytology results, 18 (7%) had high-grade cervical lesions or more severe by cytology, of whom 16 (89%) were HR-HPV-positive compared with 82 (41%) of 199 women with normal cytology (p<0.001). The most common HR-HPV types in women with a high-grade lesion or more severe by cytology were HPV-52 (44%), HPV-31 (22%), HPV-35 (22%), HPV-51 (22%) and HPV-58 (22%). HR-HPV genotypes HPV-16 or HPV-18 were found in 17% of women with high-grade lesions or more severe. HR-HPV screening applied in this population would detect 89% of those with a high-grade lesion or more severe, while 44% of women with normal or low-grade cytology would screen positive. Conclusion HR-HPV prevalence was high in this population of HIV-infected women with an uninfected partner. Choice of screening for all HR genotypes versus a subset of HR genotypes in these HIV-infected women will strongly affect the performance of an HPV screening strategy relative to cytological screening. Regional and subpopulation differences in HR-HPV genotype distributions could affect screening test performance
Exact solutions of the radial Schrodinger equation for some physical potentials
By using an ansatz for the eigenfunction, we have obtained the exact
analytical solutions of the radial Schrodinger equation for the pseudoharmonic
and Kratzer potentials in two dimensions. The energy levels of all the bound
states are easily calculated from this eigenfunction ansatz. The normalized
wavefunctions are also obtained.Comment: 13 page
Using data envelopment analysis to support the design of process improvement interventions in electricity distribution
A significant number of studies have documented the use of Data Envelopment Analysis (DEA) for efficiency measurement in the context of electricity distribution, particularly at the level of the distribution
utilities. However, their aim has been predominantly descriptive and classificatory, without any attempt
to âopenâ the black box of the transformation process. In contrast, our aim is to explore the potential of DEA to contribute to the design of effective process improvement interventions within a distribution utility.
In particular, in this paper, we study an important question within the context of DEA analysis: that is, to investigate whether differences in efficiency can be attributed to a particular managerial programme or design feature. We use two different methodologies to undertake this type of analysis. Firstly, we apply MannâWhitney rank statistics to the scores obtained from DEA in order to evaluate the statistical significance of the differences observed between an intervention programme and its control group programme.
Secondly, we undertake dynamic analysis with the Malmquist Productivity Index in order to study the impact of the introduction of a new technology on a group of units. Our case study focuses on the performance evaluation of medium-voltage power lines belonging to one of the service areas in the Public
Electricity Distribution System in Portugal. The results from our case study show that the application of DEA for process improvement interventions has great potential and should be explored in other
contexts
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