Factores de rendimiento en aplicaciones híbridas

En el entorno actual, diversas ramas de las ciencias, tienen la necesidad de auxiliarse de la computación de altas prestaciones para la obtención de resultados a relativamente corto plazo. Ello es debido fundamentalmente, al alto volumen de información que necesita ser procesada y también al costo computacional que demandan dichos cálculos. El beneficio al realizar este procesamiento de manera distribuida y paralela, logra acortar los tiempos de espera en la obtención de los resultados y de esta forma posibilita una toma decisiones con mayor anticipación. Para soportar ello, existen fundamentalmente dos modelos de programación ampliamente extendidos: el modelo de paso de mensajes a través de librerías basadas en el estándar MPI, y el de memoria compartida con la utilización de OpenMP. Las aplicaciones híbridas son aquellas que combinan ambos modelos con el fin de aprovechar en cada caso, las potencialidades específicas del paralelismo en cada uno. Lamentablemente, la práctica ha demostrado que la utilización de esta combinación de modelos, no garantiza necesariamente una mejoría en el comportamiento de las aplicaciones. Por lo tanto, un análisis de los factores que influyen en el rendimiento de las mismas, nos beneficiaría a la hora de implementarlas pero también, sería un primer paso con el fin de llegar a predecir su comportamiento. Adicionalmente, supondría una vía para determinar que parámetros de la aplicación modificar con el fin de mejorar su rendimiento. En el trabajo actual nos proponemos definir una metodología para la identificación de factores de rendimiento en aplicaciones híbridas y en congruencia, la identificación de algunos factores que influyen en el rendimiento de las mismas.

A logistic regression approach to estimating customer profit loss due to lapses in insurance

This article focuses on business risk management in the insurance industry. A methodology for estimating the profit loss caused by each customer in the portfolio due to policy cancellation is proposed. Using data from a European insurance company, customer behaviour over time is analyzed in order to estimate the probability of policy cancelation and the resulting potential profit loss due to cancellation. Customers may have up to two different lines of business contracts: motor insurance and other diverse insurance (such as, home contents, life or accident insurance). Implications for understanding customer cancellation behaviour as the core of business risk management are outlined.

Taxes de reincidència 2009 de justícia juvenil: actualització de la taxa de reincidència dels joves sotmesos a mesures de llibertat vigilada i internament en centre

Taxes de reincidència 2009 de justícia juvenil: actualització de la taxa de reincidència dels joves sotmesos a mesures de llibertat vigilada i internament en centre L’estudi actualitza les taxes de reincidència dels menors sotmesos a una mesura d’internament o de llibertat vigilada que van ser publicades a la recerca “La reincidència en el delicte en la justícia de menors” finalitzada l’any 2005 i que van iniciar la sèrie. Aquest estudi ja és el cinquè del mateix tipus i, en aquest cas, segueix els joves que van finalitzar una mesura de llibertat vigilada o d’internament l’any 2006, i els segueix fins el 31 de desembre de 2009 amb l’objectiu de saber si han comès un nou delicte que hagi estat detectat per la Xarxa d’execució penal, tant de joves com d’adults. S’ha estudiat tota la població de joves desinternats de centres, que per l’any 2006 foren 169 subjectes. En el cas de llibertat vigilada del total de joves que finalitzaren mesura l’any 2006 (N=1.017), s’ha fet una mostra de 525 subjectes (interval de confiança:95,5%; marge d’error ±3,04; p=q=50) Els resultats en llibertat vigilada apunten a un augment en la taxa de reincidència (28,8%) aquest darrer any. Aquest augment s’explica en part per la incorporació al Codi Penal dels delictes de trànsit, on els joves han fet un creixement espectacular que no hi era als anys anteriors. En canvi, en internament la taxa de reincidència ha baixat 12 punts respecte l’any anterior i és la més baixa de totes les recollides en les series fetes fins ara (50,3%). L’estudi permet comparar de forma seriada ja cinc anys d’evolució de la taxa de reincidència juvenil després de la posada en marxa de la Llei Orgànica 5/2000, de 12 de gener, reguladora de la responsabilitat penal dels menors (LORPM). Updated recidivism rates of juveniles after serving supervised freedom or custodial sentences (2009) The study updates juvenile recidivism rates in Catalonia (following an annual series that has been published during the last 4 years). The sample is compounded by juveniles after serving a penal measure (supervised freedom or custodial sentences). In this case, the young population (14-18 years old) that finished a penal measure in 2006 was followed until December 31, 2009. The results show an increasing rate of recidivism in the case of youngsters submitted to the community measure called supervised freedom (28.8%), while recidivism related to custodial sentences decrease 12 points (50.3%) Tasas de reincidencia 2009 de justicia juvenil. Actualización de la tasa de reincidencia de los jóvenes sometidos a medidas de libertad vigilada e internamiento en centro El estudio actualiza por cuarto año las tasas de reincidencia juvenil en las medidas de libertad vigilada e internamiento en Catalunya. En este caso se ha estudiado a la población que finalizó una medida el año 2006 y se les ha seguido hasta el 31 de diciembre de 2009. Los resultados nos dicen que aumenta la tasa de reincidencia de libertad vigilada (28,8%) y desciende de manera significativa en 12 puntos la de internamiento (50,3%)

Tasas de reincidencia 2009 de justicia juvenil : Actualización de la tasa de reincidencia de los jóvenes sometidos a medidas de libertad vigilada e internamiento en centro

El estudio actualiza por cuarto año las tasas de reincidencia juvenil en las medidas de libertad vigilada e internamiento en Catalunya. En este caso se ha estudiado a la población que finalizó una medida el año 2006 y se les ha seguido hasta el 31 de diciembre de 2009. Los resultados nos dicen que aumenta la tasa de reincidencia de libertad vigilada (28,8%) y desciende de manera significativa en 12 puntos la de internamiento (50,3%) L’estudi actualitza les taxes de reincidència dels menors sotmesos a una mesura d’internament o de llibertat vigilada que van ser publicades a la recerca “La reincidència en el delicte en la justícia de menors” finalitzada l’any 2005 i que van iniciar la sèrie. Aquest estudi ja és el cinquè del mateix tipus i, en aquest cas, segueix els joves que van finalitzar una mesura de llibertat vigilada o d’internament l’any 2006, i els segueix fins el 31 de desembre de 2009 amb l’objectiu de saber si han comès un nou delicte que hagi estat detectat per la Xarxa d’execució penal, tant de joves com d’adults. S’ha estudiat tota la població de joves desinternats de centres, que per l’any 2006 foren 169 subjectes. En el cas de llibertat vigilada del total de joves que finalitzaren mesura l’any 2006 (N=1.017), s’ha fet una mostra de 525 subjectes (interval de confiança:95,5%; marge d’error ±3,04; p=q=50) Els resultats en llibertat vigilada apunten a un augment en la taxa de reincidència (28,8%) aquest darrer any. Aquest augment s’explica en part per la incorporació al Codi Penal dels delictes de trànsit, on els joves han fet un creixement espectacular que no hi era als anys anteriors. En canvi, en internament la taxa de reincidència ha baixat 12 punts respecte l’any anterior i és la més baixa de totes les recollides en les series fetes fins ara (50,3%). L’estudi permet comparar de forma seriada ja cinc anys d’evolució de la taxa de reincidència juvenil després de la posada en marxa de la Llei Orgànica 5/2000, de 12 de gener, reguladora de la responsabilitat penal dels menors (LORPM). Updated recidivism rates of juveniles after serving supervised freedom or custodial sentences (2009) The study updates juvenile recidivism rates in Catalonia (following an annual series that has been published during the last 4 years). The sample is compounded by juveniles after serving a penal measure (supervised freedom or custodial sentences). In this case, the young population (14-18 years old) that finished a penal measure in 2006 was followed until December 31, 2009. The results show an increasing rate of recidivism in the case of youngsters submitted to the community measure called supervised freedom (28.8%), while recidivism related to custodial sentences decrease 12 points (50.3%)

Evaluation of subsidies programs to sell green cars: Impact on prices, quantities and efficiency

During the recent period of economic crisis, many countries have introduced scrappage schemes to boost the sale and production of vehicles, particularly of vehicles designed to pollute less. In this paper, we analyze the impact of a particular scheme in Spain (Plan2000E) on vehicle prices and sales figures as well as on the reduction of polluting emissions from vehicles on the road. We considered the introduction of this scheme an exogenous policy change and because we could distinguish a control group (non-subsidized vehicles) and a treatment group (subsidized vehicles), before and after the introduction of the Plan, we were able to carry out our analysis as a quasi-natural experiment. Our study reveals that manufacturers increased vehicle prices by the same amount they were granted through the Plan (1,000 €). In terms of sales, econometric estimations revealed an increase of almost 5% as a result of the implementation of the Plan. With regard to environmental efficiency, we compared the costs (inverted quantity of money) and the benefits of the program (reductions in polluting emissions and additional fiscal revenues) and found that the Plan would only be beneficial if it boosted demand by at least 30%.

A New open economy macroeconomic model with endogenous portfolio diversification and firms entry

This paper provides a new benchmark for the analysis of the international diversi…cation puzzle in a tractable new open economy macroeconomic model. Building on Cole and Obstfeld (1991) and Heathcote and Perri (2009), this model speci…es an equilibrium model of perfect risk sharing in incomplete markets, with endogenous portfolios and number of varieties. Equity home bias may not be a puzzle but a perfectly optimal allocation for hedging risk. In contrast to previous work, the model shows that: (i) optimal international portfolio diversi…cation is driven by home bias in capital goods, independently of home bias in consumption, and by the share of income accruing to labour. The model explains reasonably well the recent patterns of portfolio allocations in developed economies; and (ii) optimal portfolio shares are independent of market dynamics.

The impact of agglomeration effects and accessibility on wages

This paper contributes to the empirical literature on the effects of agglomeration and road accessibility on productivity of firms by looking at the case of Spain. We approach productivity indirectly by using individual wages allocated at the NUTS III level. We use a repeated cross-section of individual micro-data for the years 1995, 2002 and 2006. The availability of interprovincial travel time data for each of the three years allows controlling for transport improvements over the period by using a market potential variable. Additionally, agglomeration is approached by employment density and we control for localization economies, human capital externalities and a large set of individual and workplace characteristics. Estimating by instrumental variables, our results show a positive and significant effect of market accessibility on wages and non linear effect for employment density.

R&D cooperation between Spanish firms and scientific partners: what is the role of tertiary education?

This paper explores the factors that determine firm’s R&D cooperation with different partners, paying special attention on the role of tertiary education (degree and PhDs level) in facilitating the connection between the firms and the to scientific bodies (technology centres, public research centres and universities). Here, we attempt to answer two questions. First, are innovative firms that carry out internal and external R&D activities more likely to cooperate on R&D projects with other partners? Second, do Spanish innovative firms with a high participation of researchers with degrees or PhDs tend to cooperate more with scientific partners? To answer both questions we apply a three-dimensional approach on a firm level Panel Data with a sample of 4.998 manufacturing and services Spanish firms. First, we run a complementary test between external R&D acquisition and skilled research workers and find that firms which carry out external R&D activities obtain a greater return on R&D cooperation when they have skilled workers in R&D, especially in high-tech manufactures and KIS services. Second, we carry out a 2-step tobit model to estimate, in the first stage, the determinants that explain whether Spanish innovative firms cooperate or not; and in the second stage the factors that affect the choice of partners. And third, we apply an ordered probit model to test the marginal effects of explanatory variables on the different partners. Here we contrast some of the most interesting empirical hypotheses of previous studies, and which emphasize the role of employees with degrees and PhDs in facilitating cooperative R&D between firms and scientific partners.

Does grade retention affect achievement? Some evidence from PISA

Grade retention practices are at the forefront of the educational debate. In this paper, we use PISA 2009 data for Spain to measure the effect of grade retention on students’ achievement. One important problem when analyzing this question is that school outcomes and the propensity to repeat a grade are likely to be determined simultaneously. We address this problem by estimating a Switching Regression Model. We …find that grade retention has a negative impact on educational outcomes, but we confi…rm the importance of endogenous selection, which makes observed differences between repeaters and non-repeaters appear 14.6% lower than they actually are. The effect on PISA scores of repeating is much smaller (-10% of non-repeaters’ average) than the counterfactual reduction that non-repeaters would suffer had they been retained as repeaters (-24% of their average). Furthermore, those who repeated a grade during primary education suffered more than those who repeated a grade of secondary school, although the effect of repeating at both times is, as expected, much larger.

Avaluació i impacte de les respostes penals al fenomen de la violència de gènere a Catalunya (2007-2008)

La recerca vol fer una aproximació empírica a les respostes que des del sistema penal a Catalunya s’ofereix al fenomen de la violència de gènere. S’han explorat de forma transversal les diverses fonts estadístiques quantitatives dels diferents serveis, des del Consejo del Poder Judicial, el Departament d’Interior i el Departament de Justícia, fins a l’ Institut Català de les Dones en el període 2007-2008. Tanmateix s’ha elaborat una base de dades jurisprudencial amb totes les sentències dictades per les Audiències Provincials a Catalunya durant aquest període. L’avaluació qualitativa es realitza a partir de l’anàlisi dels programes d’intervenció existents, un focus group amb els operadors jurídics de la xarxa i l’anàlisi i buidat jurisprudencial.

Macroeconomics of extensive margins: a simple model

How do monopolistically competitive industries react to shocks in the context of a New Keynesian macro model? I bridge macroeconomics and trade theory by considering market dynamics. I use an analytically tractable closed-economy model with endogenous entry of firms and show the implications of markets structure for the transmission of real shocks on aggregate variables and welfare. Shock sources become crucial for the results: traditional productivity shocks cause an extensive effect on production; shocks on innovation cause an intensive impact. More patient populations bring the economy to a richer market, although it cushions the extensive effect after an innovation shock.

The determinants of YIc's R&D activity

This paper examines the determinants of young innovative companies’ (YICs) R&D activities taking into account the autoregressive nature of innovation. Using a large longitudinal dataset comprising Spanish manufacturing firms over the period 1990-2008, we find that previous R&D experience is a fundamental determinant for mature and young firms, albeit to a smaller extent in the case of the YICs, suggesting that their innovation behaviour is less persistent and more erratic. Moreover, our results suggest that firm and market characteristics play a distinct role in boosting the innovation activity of firms of different age. In particular, while market concentration and the degree of product diversification are found to be important in boosting R&D activities in the sub-sample of mature firms only, YICs’ spending on R&D appears to be more sensitive to demand-pull variables, suggesting the presence of credit constraints. These results have been obtained using a recently proposed dynamic type-2 tobit estimator, which accounts for individual effects and efficiently handles the initial conditions problem.

Growth in a Cross-Section of Cities: Location, Increasing Returns or Random Growth?

This article analyzes empirically the main existing theories on income and population city growth: increasing returns to scale, locational fundamentals and random growth. To do this we implement a threshold nonlinearity test that extends standard linear growth regression models to a dataset on urban, climatological and macroeconomic variables on 1,175 U.S. cities. Our analysis reveals the existence of increasing returns when per-capita income levels are beyond $19; 264. Despite this, income growth is mostly explained by social and locational fundamentals. Population growth also exhibits two distinct equilibria determined by a threshold value of 116,300 inhabitants beyond which city population grows at a higher rate. Income and population growth do not go hand in hand, implying an optimal level of population beyond which income growth stagnates or deteriorates

The Innovation and Imitation Dichotomy in Spanish firms: do absorptive capacity and the technological frontier matter?

This paper analyses whether a firm’s absorptive capacity and its distance from the technological frontier affect the choice between innovation and imitation in innovative Spanish firms. From an extensive survey of 5,575 firms during the 2004-2009 period, we found two significant results. With regard to the role of absorptive capacity, the empirical evidence shows that when innovative firms have difficulties in accessing external information and hire skilled workers, their innovative capacity is reduced. Meanwhile, with regard to distance from the technological frontier, the firms that reduce this gap manage to increase their innovative capacity at the expense of imitation. To summarise, when we studied firms’ absorptive capacity and their relative position to the technological frontier in tandem, we found that the two factors directly affected firms' ability to innovate or imitate.

Análisis, desarrolo y posicionamiento de una web 2.0

Anàlisi i desenvolupament d’una web 2.0 per taxistes, en forma de xarxa social, on puguin participar activament, anunciar la venda de les seves llicències de taxi amb informació detallada i trobin publicitat d’empreses del sector que ofereixen ofertes i promocions dels seus serveis o productes gràcies a les eines que ofereix la web a les empreses subscrites. Optimització de la web pels principals motors de cerca d’ Internet.