Search results for " Opera"
showing 10 items of 3606 documents
New descent rules for solving the linear semi-infinite programming problem
1994
The algorithm described in this paper approaches the optimal solution of a continuous semi-infinite linear programming problem through a sequence of basic feasible solutions. The descent rules that we present for the improvement step are quite different when one deals with non-degenerate or degenerate extreme points. For the non-degenerate case we use a simplex-type approach, and for the other case a search direction scheme is applied. Some numerical examples illustrating the method are given.
Survey data on the consequences of COVID-19 and home confinement on the educational community and families in Spain
2021
[EN] This paper presents a dataset concerning the consequences of the COVID-19 pandemic and home confinement on the educational community and families, and the possibilities and opportunities for the return to schools. Data were collected through an online based cross-sectional survey between June 29, 2020 and July 12, 2020 in Spain. A total of 7,305 people who had children in their care during the COVID-19 crisis and the home-confinement period responded to the survey. The survey contained items concerning (i) socio-demographic information, (ii) conciliation of work, personal and family life during confinement, (iii) the impact of the pandemic on the respondent's family, and (iv) the respo…
Impacto científico y contextualización bibliométrica de la Pediatría respecto a otras áreas temáticas
2020
[EN]: [Introduction] The purpose of this paper is twofold. On the one hand, to identify and characterise the indicators of production, citation, impact and collaboration of the Pediatrics area of the Journal Citation Reports, and on the other, to place the journal Anales de Pediatría in the context of the Spanish journals of another twenty areas and medical specialties. [Material and Method] The sources of information used to obtain the indicators were Science Citation Index- Expanded, Journal Citation Reports and Scimago Journal & Country Rank. A regression analysis was performed to check the correlation between the citation and other variables. [Results] Pediatrics ranked 8th in scientifi…
Impacto científico y contextualización bibliométrica de la Pediatría respecto a otras áreas temáticas
2020
[ES] Introducción El objetivo de este trabajo es doble. Por una parte, identificar y caracterizar los indicadores de producción, citación, impacto y colaboración del área Pediatrics del Journal Citation Reports, y por otra, estudiar a la revista Anales de Pediatría en el contexto de las revistas españolas de otras 20 áreas y especialidades médicas. Material y método Las fuentes de información utilizadas para la obtención de los indicadores fueron Science Citation Index-Expanded, Journal Citation Reports y Scimago Journal & Country Rank. Se realizó un análisis de regresión para comprobar la correlación entre la citación y otras variables. Resultados Pediatrics ocupó el 8.o lugar en producció…
Il diritto islamico nel sistema delle fonti normative dell'ordinamento iraniano
2011
The essay aims to analyze the Iranian legal order by dweeling upon the connection between the religious legal sources and the secular ones. The acknowledgement of an apical right, whose origin is divine, coexists indeed with the law-making process provisions. In particular, the Author stresses the distinctive features and inherent contradictions of this legal order, which is defined as a "constitutional theocracy". Furthermore, the Author also addresses the duties of the Council of Guardians, which plays a central role in the definition of the hierarchy of legal sources, working both as interpreter of the Constitution and as controller of the compliance of ordinary and constitutional laws w…
Laparoscopic surgical management of localized recurrent ovarian cancer: a single-institution experience
2014
Background: Optimally, secondary cytoreduction is acknowledged as a valid option in terms of oncologic outcome for patients with platinum-sensitive recurrent ovarian cancer. In cases of localized relapse, a laparoscopic approach has been attempted at various institutions, but studies on its role for this subset of patients still are limited. This report describes the authors' experience using laparoscopic secondary cytoreduction for patients with localized recurrent ovarian cancer. The results from a retrospective analysis of a prospective case series are reported. Methods: Between October 2011 and May 2013, 29 patients with localized recurrent ovarian cancer were selected for a laparoscopi…
Review of Classical Non-self-adjoint Spectral Theory
2019
The first section of this chapter deals with Fredholm theory in the spirit of Appendix A in Helffer and Sjostrand (Mm Soc Math Fr (NS) 24–25:1–228, 1986), see also an appendix in Melin and Sjostrand (Asterique 284:181–244, 2003) and Sjostrand and Zworski (Ann Inst Fourier 57:2095–2141, 2007). The remaining sections give a brief account of the very beautiful classical theory of non-self-adjoint operators, taken from a section in Sjostrand (Lectures on Resonances) which is a brief account of parts of the classical book by Gohberg and Krein (Introduction to the Theory of Linear Non-Selfadjoint Operators. Translations of Mathematical Monographs, vol 18. AMS, Providence, 1969).
Distribution of Eigenvalues for Semi-classical Elliptic Operators with Small Random Perturbations, Results and Outline
2019
In this chapter we will state a result asserting that for elliptic semi-classical (pseudo-)differential operators the eigenvalues are distributed according to Weyl’s law “most of the time” in a probabilistic sense. The first three sections are devoted to the formulation of the results and in the last section we give an outline of the proof that will be carried out in Chaps. 16 and 17.
1,3,5-triisopropylbenzene diffusion in polystyrene solutions
1996
Self-diffusion coefficients of 1,3,5-triisopropylbenzene (TIB) in binary solutions with polystyrene and ternary mixtures comprised of TIB, toluene, and polystyrene have been measured by static gradient nuclear magnetic resonance (SG-NMR) techniques. These data, as well as mutual-diffusion coefficient data measured by capillary column inverse gas chromatography (CCIGC), have been analyzed here with the Vrentas-Duda free-volume diffusion model. Although both binary and ternary diffusion coefficient data can be accurately correlated with the model, the results contradict those of an earlier investigation, which suggested that TIB diffuses as a single unit in polystyrene solutions. The new data…
The effects of self-efficacy on computer usage
1995
Abstract This paper examines the effect of self-efficacy, belief in one's capabilities of using a computer in the accomplishment of specific tasks, on computer usage. It introduces an extended technology acceptance model (TAM) that explicitly incorporates self-efficacy and its determinants (experience and organizational support) as factors affecting computer anxiety, perceived ease of use, perceived usefulness and the use of computer technology. A survey of 450 microcomputer users in Finland found strong support for the conceptual model. In accordance with TAM, perceived usefulness had a strong direct effect on usage, while perceived ease of use had indirect effect on usage through perceive…