12 resultados para Harp with instrumental ensemble
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
During the last two decades there has been an increase in using dynamic tariffs for billing household electricity consumption. This has questioned the suitability of traditional pricing schemes, such as two-part tariffs, since they contribute to create marked peak and offpeak demands. The aim of this paper is to assess if two-part tariffs are an efficient pricing scheme using Spanish household electricity microdata. An ordered probit model with instrumental variables on the determinants of power level choice and non-paramentric spline regressions on the electricity price distribution will allow us to distinguish between the tariff structure choice and the simultaneous demand decisions. We conclude that electricity consumption and dwellings’ and individuals’ characteristics are key determinants of the fixed charge paid by Spanish households Finally, the results point to the inefficiency of the two-part tariff as those consumers who consume more electricity pay a lower price than the others.
Resumo:
This paper examines competition between generic and brand-name drugs in the regulated Spanish pharmaceutical market. A nested logit demand model is specified for the three most consumed therapeutic subgroups in Spain: statins (anticholesterol), selective serotonin reuptake inhibitors (antidepressants) and proton pump inhibitors (antiulcers). The model is estimated with instrumental variables from a panel of monthly prescription data from 1999 to 2005. The dataset distinguishes between three different levels of patients’ copayments within the prescriptions and the results show that the greater the level of insurance that the patient has (and therefore the lower the patient’s copayment), the lower the proportion of generic prescriptions made by physicians. It seems that the low level of copayment has delayed the penetration of generics into the Spanish market. Additionally, the estimation of the demand model suggests that the substitution rules and promotional efforts associated with the reference pricing system have increased generic market share, and that being among the first generic entrants has an additional positive effect.
Resumo:
El objetivo de este estudio es identificar factores que contribuyen a mantener un enfoque básicamente instrumental para enseñar los sistemas externos de representación matemáticos y lingüísticos en las primeras edades de escolarización. En el estudio han participado 123 maestros de Educación Infantil de diversos centros escolares públicos de Andalucía, Asturias, Cataluña y Navarra que han asistido a cursos de formación permanente del profesorado. El análisis cualitativo realizado se basa en grupos de discusión a partir de tópicos. Los resultados evidencian la influencia de diversos factores: el currículo de Educación Infantil; las concepciones del profesorado; las presiones entre etapas educativas; y, finalmente, la presión social. La identificación de los factores asociados a una enseñanza instrumental de los sistemas externos de representación puede entenderse como un tipo de información relevante acerca de las condiciones de la enseñanza de estos sistemas que, además, pueden servir de base para reconstruir las prácticas educativas
Resumo:
The effect of pork fat reduction (from 44% to 20% final fat content) and its partial substitution by sunflower oil (3% addition) on the physicochemical, instrumental and sensory properties throughout storage time of small caliber non-acid fermented sausages (fuet type) with reduced sodium content (with partial substitution of NaCl by KCl and K-lactate) and without direct addition of nitrate and nitrite (natural nitrate source used instead), was studied. Results showed that sausages with reduced fat (10% initial fat content) and with acceptable sensory characteristics can be obtained by adding to the shoulder lean (8% fat content) during the grinding, either 3.3% backfat (3% fat content) or 3% sunflower oil, both previously finely comminuted with lean. Furthermore, sunflower oil showed to be suitable for partial pork backfat substitution in very lean fermented sausages, conferring desirable sensory properties similar to those of sausages with standard fat content. The sensory quality of the sausages was maintained after three-month cold storage in modified atmosphere.
Resumo:
This paper studies the impact of instrumental voting on information demand and mass media behaviour during electoral campaigns. If voters act instrumentally then information demand should increase with the closeness of an election. Mass media are modeled as profit-maximizing firms that take into account information demand, the value of customers to advertisers and the marginal cost of customers. Information supply should be larger in electoral constituencies where the contest is expected to be closer, there is a higher population density, and customers are on average more profitable for advertisers. The impact of electorate size is theoretically undetermined. These conclusions are then tested with comfortable results on data from the 1997 general election in Britain.
Resumo:
Several methods have been suggested to estimate non-linear models with interaction terms in the presence of measurement error. Structural equation models eliminate measurement error bias, but require large samples. Ordinary least squares regression on summated scales, regression on factor scores and partial least squares are appropriate for small samples but do not correct measurement error bias. Two stage least squares regression does correct measurement error bias but the results strongly depend on the instrumental variable choice. This article discusses the old disattenuated regression method as an alternative for correcting measurement error in small samples. The method is extended to the case of interaction terms and is illustrated on a model that examines the interaction effect of innovation and style of use of budgets on business performance. Alternative reliability estimates that can be used to disattenuate the estimates are discussed. A comparison is made with the alternative methods. Methods that do not correct for measurement error bias perform very similarly and considerably worse than disattenuated regression
Resumo:
Since its origins, the European Union has striven to be an actor on the International scene and a place in conflict Management. Yet the EU’s lack of activity cannot be justified by a mere lack of capacities. The EU counts with numerous political, economic, and, since 2003, civil and military instruments that should allow it to precede a comprehensive conflict response. This publication consists of a description of these instruments and an analysis of the final use that the Union makes of them in the different stages of a conflict. Examples will show us the EU’s main weakness in providing a comprehensive and timely response when a conflict breaks out.
Resumo:
Information on level density for nuclei with mass numbers A?20250 is deduced from discrete low-lying levels and neutron resonance data. The odd-mass nuclei exhibit in general 47 times the level density found for their neighboring even-even nuclei at the same excitation energy. This excess corresponds to an entropy of ?1.7kB for the odd particle. The value is approximately constant for all midshell nuclei and for all ground state spins. For these nuclei it is argued that the entropy scales with the number of particles not coupled in Cooper pairs. A simple model based on the canonical ensemble theory accounts qualitatively for the observed properties.
Resumo:
The extended Gaussian ensemble (EGE) is introduced as a generalization of the canonical ensemble. This ensemble is a further extension of the Gaussian ensemble introduced by Hetherington [J. Low Temp. Phys. 66, 145 (1987)]. The statistical mechanical formalism is derived both from the analysis of the system attached to a finite reservoir and from the maximum statistical entropy principle. The probability of each microstate depends on two parameters ß and ¿ which allow one to fix, independently, the mean energy of the system and the energy fluctuations, respectively. We establish the Legendre transform structure for the generalized thermodynamic potential and propose a stability criterion. We also compare the EGE probability distribution with the q-exponential distribution. As an example, an application to a system with few independent spins is presented.
Resumo:
This Handbook contains a collection of articles describing instrumental techniques used for Materials, Chemical and Biosciences research that are available at the Scientific and Technological Centers of theUniversity of Barcelona (CCiTUB). The CCiTUB are a group of facilities of the UB that provide both the research community and industry with ready access to a wide range of major instrumentation.Together with the latest equipment and technology, the CCiTUB provide expertise in addressing the methodological research needs of the user community and they also collaborate in R+D+i Projectswith industry. CCiTUB specialists include technical and Ph.D.-level professional staff members who are actively engaged in methodological research. Detailed information on the centers’ resources andactivities can be found at the CCiTUB website www.ccit.ub.edu ...
Resumo:
Past temperature variations are usually inferred from proxy data or estimated using general circulation models. Comparisons between climate estimations derived from proxy records and from model simulations help to better understand mechanisms driving climate variations, and also offer the possibility to identify deficiencies in both approaches. This paper presents regional temperature reconstructions based on tree-ring maximum density series in the Pyrenees, and compares them with the output of global simulations for this region and with regional climate model simulations conducted for the target region. An ensemble of 24 reconstructions of May-to-September regional mean temperature was derived from 22 maximum density tree-ring site chronologies distributed over the larger Pyrenees area. Four different tree-ring series standardization procedures were applied, combining two detrending methods: 300-yr spline and the regional curve standardization (RCS). Additionally, different methodological variants for the regional chronology were generated by using three different aggregation methods. Calibration verification trials were performed in split periods and using two methods: regression and a simple variance matching. The resulting set of temperature reconstructions was compared with climate simulations performed with global (ECHO-G) and regional (MM5) climate models. The 24 variants of May-to-September temperature reconstructions reveal a generally coherent pattern of inter-annual to multi-centennial temperature variations in the Pyrenees region for the last 750 yr. However, some reconstructions display a marked positive trend for the entire length of the reconstruction, pointing out that the application of the RCS method to a suboptimal set of samples may lead to unreliable results. Climate model simulations agree with the tree-ring based reconstructions at multi-decadal time scales, suggesting solar variability and volcanism as the main factors controlling preindustrial mean temperature variations in the Pyrenees. Nevertheless, the comparison also highlights differences with the reconstructions, mainly in the amplitude of past temperature variations and in the 20th century trends. Neither proxy-based reconstructions nor model simulations are able to perfectly track the temperature variations of the instrumental record, suggesting that both approximations still need further improvements.
Resumo:
Past research in using ICTs (Information and Communication Technologies) in interpersonal communication showed that age plays an important role. There is a general assumption that the elderly are left behind regarding the adoption and the use of ICTs. Furthermore, elders tend to use ICTs mainly for instrumental purposes and the use is rather non-sophisticated. When elders are using ICTs to maintain their social network, similar patterns could be found: They start using internet, or intensify its use, when their children move abroad while they might decrease using the tool if the motivation ends. In this research we explore elders' incentives to go online and use internet services to communicate; the type of agencies they use to communicate with children and grandchildren abroad; and the situations that make them stop using the ICTs or even reject internet mediated communications. We base our discussion on the empirical evidence the two authors gathered in different cities and countries: Barcelona, Romania, Toronto, Los Angeles, Montevideo and Lima, through semi-structured interviews and observation, with people aged 60 years old and over. The results show that the ability for using ICT tools in an autonomous way is a better explanation than age. In this, we distinguish between assisted users and autonomous users. We found that oldest seniors and those seniors who are less socially active are more likely to be assisted users than those who are socially or professionally active. For them communication with their children and grandchildren abroad follows no agency or it is mediated by significant others from their local social network, who are able to use ICTs and select specific information to share, in the second step, with the elder. For some younger participants the use of ICTs is rather situational and imposed by their children or grandchildren, who installed the tool in the first place and assisted them in using it. Finally, other elders describe a proficient and independent use of ICTs so they use the devices and services the way they want to.We discuss the implications of the patterns in using ICTs, for elders' social life and their relationships with children and grandchildren. First, we emphasis the fact that those elders rejecting the ICTs or being unskilled in using them to communicate might be left out from their family circle, particularly when children are abroad -they would experience more isolation. Second, we underline the fact that when children and grandchildren are the ones that control the ICTs used by their parents and grandparents, they are controlling also the information flow and this will redefine the power relations between elders and their younger relatives.