On the concept of optimality interval

The approximants to regular continued fractions constitute `best approximations' to the numbers they converge to in two ways known as of the first and the second kind.This property of continued fractions provides a solution to Gosper's problem of the batting average: if the batting average of a baseball player is 0.334, what is the minimum number of times he has been at bat? In this paper, we tackle somehow the inverse question: given a rational number P/Q, what is the set of all numbers for which P/Q is a `best approximation' of one or the other kind? We prove that inboth cases these `Optimality Sets' are intervals and we give aprecise description of their endpoints.

Endogenous population subgroups: the best population partition and optimal number of groups

The aim of this paper is to suggest a method to find endogenously the points that group the individuals of a given distribution in k clusters, where k is endogenously determined. These points are the cut-points. Thus, we need to determine a partition of the N individuals into a number k of groups, in such way that individuals in the same group are as alike as possible, but as distinct as possible from individuals in other groups. This method can be applied to endogenously identify k groups in income distributions: possible applications can be poverty

Equilibrium play and best response to (Stated) beliefs in constant sum games

We report experimental results on one-shot two person 3x3 constant sum games played by non-economists without previous experience in the laboratory. Although strategically our games are very similar to previous experiments in which game theory predictions fail dramatically, 80% of actions taken in our experiment coincided with the prediction of the unique Nash equilibrium in pure strategies and 73% of actions were best responses to elicited beliefs. We argue how social preferences, presentation effects and belief elicitation procedures may influence how subjects play in simple but non trivial games and explain the diferences we observe with respect to previous work.

What works best for getting the unemployed back to work: employment services or small-business assistance programs? evidence from Romania

Recent empirical evidence has found that employment services and small-business assistance programmes are often successful at getting the unemployed back to work. Â One important concern of policy makers is to decide which of these two programmes is more effective and for whom. Â Using unusually rich (for transition economies) survey data and matching methods, I evaluate the relative effectiveness of these two programmes in Romania. Â While I find that employment services (ES) are, on average, more successful than a small-business assistance programme (SBA), estimation of heterogeneity effects reveals that, compared to non-participation, ES are effective for workers with little access to informal search channels, and SBA works for less-qualified workers and those living in rural areas. Â When comparing ES to SBA, I find that ES tend to be more efficient than SBA for workers without a high-school degree, and that the opposite holds for the more educated workers.

Planificación de aplicaciones best-effort y soft real-time en NOWs

La aparición de nuevos tipos de aplicaciones, como vídeo bajo demanda, realidad virtual y videoconferencias entre otras, caracterizadas por la necesidad de cumplir sus deadlines. Este tipo de aplicaciones, han sido denominadas en la literatura aplicaciones soft-real time (SRT) periódicas. Este trabajo se centra en el problema de la planificación temporal de este nuevo tipo de aplicaciones en clusters no dedicados.

Codes of best practice in competitive markets for managers

We study firms' corporate governance in environments where possibly heterogeneous shareholders compete for possibly heterogeneous managers. A firm, formed by a shareholder and a manager, can sign either an incentive contract or a contract including a Code of Best Practice. A Code allows for a better manager's control but makes manager's decisions hard to react when market conditions change. It tends to be adopted in markets with low volatility and in low-competitive environments. The firms with the best projects tend to adopt the Code when managers are not too heterogeneous while the best managers tend to be hired through incentive contracts when the projects are similar. Although the matching between shareholders and managers is often positively assortative, the shareholders with the best projects might be willing to renounce to hire the best managers, signing contracts including Codes with lower-ability managers.

Los sistemas participativos en las políticas de gestión de RSU: ejemplos de best-practices y el caso español

En el presente estudio se analizan los sistemas de gestión de RSU de Alemania, Noruega y California, considerados best-practices, desde la perspectiva de la creación de las políticas que los han hecho posibles. De este análisis se destacan como elementos importantes el liderazgo institucional, los acuerdos con la industria y el debate social. Posteriormente se analiza el caso de España y de Cataluña, comparándolo con los casos destacados y los elementos seleccionados. En este análisis se sigue la evolución de su legislación, planes y programas y se consideran los elementos que definen el panorama actual. Finalmente, siguiendo las recomendaciones de diversos autores y la voluntad del actual programa catalán, se plantea un sistema participativo para la elaboración de estas políticas.

Decomposable approximations of nuclear C*-algebras

We show that nuclear C*-algebras have a re ned version of the completely positive approximation property, in which the maps that approximately factorize through finite dimensional algebras are convex combinations of order zero maps. We use this to show that a separable nuclear C*-algebra A which is closely contained in a C*-algebra B embeds into B.

Estudio sobre la recepción del modelo de best seller norteamericano en los best sellers europeos. Los casos de Francia y España.

L’objectiu d’aquest projecte és analitzar la qualitat literària dels best sellers i observar les limitacions d’aquest anàlisi. Deguda la complexitat del fenòmen best seller, i tot i ser conscients de que són obres que s’han d’abordar des d’una perspectiva pluridisciplinar, vam decidir començar aquest projecte analitzant tres best sellers espanyols des de la metodologia de l’estilística i de la narratologia. Les obres analitzades són 'La sombra del viento' de Carlos Ruiz Zafón, 'Un milagro en equilibrio', de Lucía Etxevarría, i 'El capitán Alatriste', de Pérez Reverte, i l’anàlisi és de tipus quantitatiu, de les estructures emprades per a l’expressió de lo metafòric, dels personatges, trames i tòpics. Les conclusions varen ser que, des d’un punt de vista estilístic, es pot demostrar la mala qualitat literària d’aquestes obres, així com la seva relació amb la tradició del gènere del folletí, amb el que comparteixen moltes característiques. Tanmateix, una altra de les conclusions de l’estudi fou que abordar el best seller des de l’estilística no ofereix una visió completa d’aquest fenòmen. Aquest projecte doncs, que té per títol “Estudio estilístico de tres casos de best seller en el ámbito español: 'La sombra del viento', 'Un milagro en equilibrio' y 'El capitán Alatriste'” ha d’ampliar-se en catàleg i en metodologia, adoptant vàries perspectives simultàneament, que ofereixin una visió adecuada de la complexitat del fenòmen. El catàleg s’ha extès a 15 obres en l’àmbit espanyol, i a 15 més en l’àmbit francès, durant el 2008, i la perspectiva multidisciplinar engloba estudis culturals, de recepció i sociologia. Des d’aquesta nova base metodològica i teòrica, s’han realitzat 500 enquestes a lectors a Barcelona i a París, en diferents punts de venta de llibres, durant el 2010.

MIinimal N-point diameters and f-best-packing constants in Rd[superindex]

Vegeu el resum a l'inici del document de l'arxiu adjunt

COIM-BEST main contributions for a better joint response

El projecte COIM-BEST ha investigat com, per mitjà de la formació, es pot millorar la coordinació entre múltiples agències per fer front a les situacions crítiques que es produeixen en les grans emergències. Entre les conclusions de l’estudi COIM-BEST, que ja ha rebut bones valoracions per part de la comissió europea, es destaca la necessitat d’una bona coordinació entre els cossos i agents que participen en la gestió de les grans crisis, generar una confiança entre aquests actors, harmonitzar la formació i una bona articulació de les categories de comandament que es fan càrrec de la direcció de la gestió de l’emergència. El projecte COIM-BEST s'emmarca en el Programa per a la prevenció, preparació i gestió de les conseqüències del terrorisme i altres riscos relacionats amb la seguretat (CIPS) de la Direcció General de Justícia, Llibertat i Seguretat de la Comissió Europea i compta amb la col·laboració de l‘Institut de Seguretat Pública de Catalunya, la Fondazione per la Ricerca sulle Migrazione e Integrazione delle Tecnologie (FORMIT), el Global Law Enforcement Institute i la Universitat Politècnica de Catalunya

Reusing IMS-LD formalized best practices in collaborative learning structuring

Designs of CSCL (Computer Supported Collaborative Learning)activities should be flexible, effective and customizable toparticular learning situations. On the other hand, structureddesigns aim to create favourable conditions for learning. Thus,this paper proposes the collection of representative and broadlyaccepted (best practices) structuring techniques in collaborative learning. With the aim of establishing a conceptual common ground among collaborative learning practitioners and softwaredevelopers, and reusing the expertise that best practicesrepresent, the paper also proposes the formulation of these techniques as patterns: the so-called CLFPs (CollaborativeLearning Flow Patterns). To formalize these patterns, we havechosen the educational modelling language IMS Learning Design (IMS-LD). IMS-LD has the capability to specify many of the collaborative characteristics of the CLFPs. Nevertheless, the language bears limited capability for describing the services that mediate interactions within a learning activity and the specification of temporal or rotated roles. This analysis isdiscussed in the paper, as well as our approaches towards thedevelopment of a system capable of integrating tools using IMSLDscripts and a CLFP-based Learning Design authoring tool.

Weak approximations. A Malliavin calculus approach

We introduce a variation of the proof for weak approximations that issuitable for studying the densities of stochastic processes which areevaluations of the flow generated by a stochastic differential equation on a random variable that maybe anticipating. Our main assumption is that the process and the initial random variable have to be smooth in the Malliavin sense. Furthermore if the inverse of the Malliavin covariance matrix associated with the process under consideration is sufficiently integrable then approximations fordensities and distributions can also be achieved. We apply theseideas to the case of stochastic differential equations with boundaryconditions and the composition of two diffusions.

Take-the-best and other simple strategies: Why and when they work 'well' in binary choice

The effectiveness of decision rules depends on characteristics of bothrules and environments. A theoretical analysis of environments specifiesthe relative predictive accuracies of the lexicographic rule 'take-the-best'(TTB) and other simple strategies for binary choice. We identify threefactors: how the environment weights variables; characteristics of choicesets; and error. For cases involving from three to five binary cues, TTBis effective across many environments. However, hybrids of equal weights(EW) and TTB models are more effective as environments become morecompensatory. In the presence of error, TTB and similar models do not predictmuch better than a naïve model that exploits dominance. We emphasizepsychological implications and the need for more complete theories of theenvironment that include the role of error.