Agent based simulation to optimise emergency departments

Nowadays, many of the health care systems are large and complex environments and quite dynamic, specifically Emergency Departments, EDs. It is opened and working 24 hours per day throughout the year with limited resources, whereas it is overcrowded. Thus, is mandatory to simulate EDs to improve qualitatively and quantitatively their performance. This improvement can be achieved modelling and simulating EDs using Agent-Based Model, ABM and optimising many different staff scenarios. This work optimises the staff configuration of an ED. In order to do optimisation, objective functions to minimise or maximise have to be set. One of those objective functions is to find the best or optimum staff configuration that minimise patient waiting time. The staff configuration comprises: doctors, triage nurses, and admissions, the amount and sort of them. Staff configuration is a combinatorial problem, that can take a lot of time to be solved. HPC is used to run the experiments, and encouraging results were obtained. However, even with the basic ED used in this work the search space is very large, thus, when the problem size increases, it is going to need more resources of processing in order to obtain results in an acceptable time.

Preparació de puntes de tungstè per a microscòpia d'efecte túnel (STM)

Es presenten els resultats experimentals obtinguts durant l’estudi sistemàtic realitzat de la preparació electroquímica de puntes de tungstè per al Microscopi d’Efecte Túnel (STM), fent servir dos electròlits: KOH i NaOH. L’estudi sobre la morfologia, longitud de la punta i radi de curvatura de la punta en funció del voltatge aplicat i les concentracions de l’electròlit es descriu al capítol 3. La caracterització de les puntes es va dur a terme, per una part, mitjançant un microscòpic electrònic de rastreig (SEM) i per l’altre banda, amb el ús de les puntes obtingudes al STM. En resumen, els resultats mostren que ambdós electròlits permeten obtenir puntes que es poden fer servir amb èxit per l’obtenció d’imatges amb l’STM. Les millors puntes són aquelles que s’obtenen dins de rangs de concentracions d’electròlit baixes, entre valor de 10 a 15% en pes pel NaOH i entre 10 i 20% pel KOH i rangs de voltatge entre 3 a 7 V pel NaOH i 4 a 8 V pel KOH. S’observa que es requereixen temps d’atac electroquímic menors fent servir com a electròlit NaOH. S’estudia, en el capítol 4, el tractament que requereix la punta per tal d’eliminar les impureses de la seva superfície. Es realitzen diferents proves amb tres mètodes de neteja: (1) tractament químic, (2) bombardeig iònic i (3) tractament tèrmic de recuit. En el capítol 5 del projecte s’analitzen les imatges d’una mostra d’or, Au(110), d’estructura coneguda, amb el microscopi d’efecte túnel STM) del laboratori fent servir les puntes obtingudes sota les condicions considerades òptimes. El resultat confirma el bon comportament de les puntes obtingudes sota les condicions descrites en els capítols anteriors i establert una pauta a seguir per obtenir puntes d’una manera senzilla i reproduïble.

Implantación CRM en un club deportivo

La propuesta CRM que se pretende ofrecer consiste en una herramienta estratégica de negocio para gestionar las relaciones con los clientes. La aplicación está desarrollada bajo un prisma Siebel para un determinado club deportivo. Esta herramienta ha de permitir estudiar todas las posibles oportunidades de negocio cubriendo la necesidad de saber en cualquier momento la circunstancia personalizada de cada cliente (socio o no socio) y de sus trámites. El objetivo fundamental del CRM es lograr la fidelización del cliente maximizando los recursos utilizados, mejorar los servicios ofrecidos en un grado óptimo y aumentar la cuenta de resultados. Para ello se plantea implantar una aplicación totalmente configurada y adaptada a las necesidades de un club deportivo.

Creació d'un sistema d'informació geogràfica de carreteres : problema logístic de l'empresa Vall Companys Grup

En la logística de Vall Companys Grup, un problema fonamental que cal resoldre és el de la situació geogràfica de tots els elements que participen en la logística, com ara fàbriques, granges, camions i magatzems; a més, se n'han d'estudiar les interrelacions per a aconseguir un aprofitament òptim dels recursos disponibles. Per a resoldre aquest problema, l'eina adequada seria un sistema d'informació geogràfica (SIG). En aquest projecte s'estudia què és un SIG i els conceptes que engloba, i se'n presenta un de comercial: Geomedia Professional 5.2. Fent servir aquest producte, s'ha construït un prototipus que estableix les bases per a poder resoldre el problema de logística de Vall Companys Grup i que mostra les potencialitats de Geomedia Professional 5.2.

Configuración de un equipo de proyecto informático eficiente

Aquest treball se circumscriu en l'àmbit de la gestió de projectes, una activitat que fa referència a l'òptima utilització dels recursos financers, materials i humans per tal de desenvolupar un treball determinat i únic sota un confinament temporal i econòmic precís.

Mapping sub-flows to p2mp LSPs

In previous work we proposed a multi-objective traffic engineering scheme (MHDB-S model) using different distribution trees to multicast several flows. In this paper, we propose a heuristic algorithm to create multiple point-to-multipoint (p2mp) LSPs based on the optimum sub-flow values obtained with our MHDB-S model. Moreover, a general problem for supporting multicasting in MPLS networks is the lack of labels. To reduce the number of labels used, a label space reduction algorithm solution is also considered

A quantum molecular similarity analysis of changes in molecular electron density caused by basis set flotation and electric field application

Quantum molecular similarity (QMS) techniques are used to assess the response of the electron density of various small molecules to application of a static, uniform electric field. Likewise, QMS is used to analyze the changes in electron density generated by the process of floating a basis set. The results obtained show an interrelation between the floating process, the optimum geometry, and the presence of an external field. Cases involving the Le Chatelier principle are discussed, and an insight on the changes of bond critical point properties, self-similarity values and density differences is performed

Síntesi i propietats de vidres metàl•lics massissos i materials nanocomposites basats en Fe per aplicacions com a materials magnètics tous

Estudi realitzat a partir d’una estada a l’ Institut für Komplexe Materialien, Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden, entre 2010 i 2011. S'ha explorat l'efecte de les condicions i influència dels elements d'aleació en la capacitat de formació de vidre, l'estructura i les propietats tèrmiques i magnètiques de vidres metàl•lics massissos i materials nanocristal•lins en base Fe. La producció d'aquests materials en forma de cintes de unes 20 micres de gruix ha estat àmpliament estudiada i s'ha vist que presenten unes propietats excel•lents com a materials magnètics tous. El propòsit general d'aquest projecte era l'obtenció de composicions òptimes amb alta capacitat de formar vidre i amb excel•lents propietats magnètiques com a materials magnètics tous combinat amb bones propietats mecàniques. El projecte prenia com a punt de partida l'aliatge [FeCoBSi]96Nb4 ja que és el que presenta millor capacitat de formar vidre i presenta una alta imantació de saturació i baix camp coercitiu. S'ha fet un estudi dels factors fonamentals que intervenen en la formació de l'estat vitri. La composició abans esmentada ha estat variada amb l'addició d'altres elements per estudiar com afecten aquests nous elements a les propietats, la formació de vidre i l'estructura dels aliatges resultants amb l'objectiu de millorar-ne les propietats magnètiques i la capacitat de formació de vidre. Entre altres s'ha usat el Zr, Mo, Y i el Gd per millorar la formació de vidre; i el Co i el Ni per millorar les propietats magnètiques a alta temperatura. S'han estudiat les relacions entre la capacitat de formació de vidre i la seva estabilitat tèrmica, la resistència a la cristal•lització i la estructura de l'aliatge resultant després del procés de solidificació. Per aquest estudi s'han determinat els mecanismes que controlen la transformació i la seva cinètica així com les fases que es formen durant el tractament tèrmic permetent la formulació de models predictius.

Suitability of GRIND-based principal properties for the description of molecular similarity and ligand-based virtual screening

The information provided by the alignment-independent GRid Independent Descriptors (GRIND) can be condensed by the application of principal component analysis, obtaining a small number of principal properties (GRIND-PP), which is more suitable for describing molecular similarity. The objective of the present study is to optimize diverse parameters involved in the obtention of the GRIND-PP and validate their suitability for applications, requiring a biologically relevant description of the molecular similarity. With this aim, GRIND-PP computed with a collection of diverse settings were used to carry out ligand-based virtual screening (LBVS) on standard conditions. The quality of the results obtained was remarkable and comparable with other LBVS methods, and their detailed statistical analysis allowed to identify the method settings more determinant for the quality of the results and their optimum. Remarkably, some of these optimum settings differ significantly from those used in previously published applications, revealing their unexplored potential. Their applicability in large compound database was also explored by comparing the equivalence of the results obtained using either computed or projected principal properties. In general, the results of the study confirm the suitability of the GRIND-PP for practical applications and provide useful hints about how they should be computed for obtaining optimum results.

Distortion control for delay-sensitive sources

We investigate the problem of finding minimum-distortion policies for streaming delay-sensitive but distortion-tolerant data. We consider cross-layer approaches which exploit the coupling between presentation and transport layers. We make the natural assumption that the distortion function is convex and decreasing. We focus on a single source-destination pair and analytically find the optimum transmission policy when the transmission is done over an error-free channel. This optimum policy turns out to be independent of the exact form of the convex and decreasing distortion function. Then, for a packet-erasure channel, we analytically find the optimum open-loop transmission policy, which is also independent of the form of the convex distortion function. We then find computationally efficient closed-loop heuristic policies and show, through numerical evaluation, that they outperform the open-loop policy and have near optimal performance.

Multiuser detection with an unknown number of active users: receiver design

In multiuser detection, the set of users active at any time may be unknown to the receiver. In these conditions, optimum reception consists of detecting simultaneously the set of activeusers and their data, problem that can be solved exactly by applying random-set theory (RST) and Bayesian recursions (BR). However, implementation of optimum receivers may be limited by their complexity, which grows exponentially with the number of potential users. In this paper we examine three strategies leading to reduced-complexity receivers.In particular, we show how a simple approximation of BRs enables the use of Sphere Detection (SD) algorithm, whichexhibits satisfactory performance with limited complexity.

Children in the welfare state. A social investment approach

Children occupy centre-stage in any new welfare equilibrium. Failure to support families may produce either of two undesirable scenarios. We shall see a society without children if motherhood remains incompatible with work. A new family policy needs to recognize that children are a collective asset and that the cost of having children is rising. The double challenge is to eliminate the constraints on having children in the first place, and to ensure that the children we have are ensured optimal opportunities. The simple reason why a new social contract is called for is that fertility and child quality combine both private utility and societal gains. And like no other epoch in the past, the societal gains are mounting all-the-while that families’ ability to produce these social gains is weakening.In the following 1 analyze the twin challenges of fertility and child development. I then examine which kind of policy mix will ensure both the socially desired level of fertility and investment in our children? The task is to identify a Paretian optimum that will maximize efficiency gains and social equity simultaneously.

Experimental design on the simplex

Optimum experimental designs depend on the design criterion, the model andthe design region. The talk will consider the design of experiments for regressionmodels in which there is a single response with the explanatory variables lying ina simplex. One example is experiments on various compositions of glass such asthose considered by Martin, Bursnall, and Stillman (2001).Because of the highly symmetric nature of the simplex, the class of models thatare of interest, typically Scheff´e polynomials (Scheff´e 1958) are rather differentfrom those of standard regression analysis. The optimum designs are also ratherdifferent, inheriting a high degree of symmetry from the models.In the talk I will hope to discuss a variety of modes for such experiments. ThenI will discuss constrained mixture experiments, when not all the simplex is availablefor experimentation. Other important aspects include mixture experimentswith extra non-mixture factors and the blocking of mixture experiments.Much of the material is in Chapter 16 of Atkinson, Donev, and Tobias (2007).If time and my research allows, I would hope to finish with a few comments ondesign when the responses, rather than the explanatory variables, lie in a simplex.ReferencesAtkinson, A. C., A. N. Donev, and R. D. Tobias (2007). Optimum ExperimentalDesigns, with SAS. Oxford: Oxford University Press.Martin, R. J., M. C. Bursnall, and E. C. Stillman (2001). Further results onoptimal and efficient designs for constrained mixture experiments. In A. C.Atkinson, B. Bogacka, and A. Zhigljavsky (Eds.), Optimal Design 2000,pp. 225–239. Dordrecht: Kluwer.Scheff´e, H. (1958). Experiments with mixtures. Journal of the Royal StatisticalSociety, Ser. B 20, 344–360.1

Strategies for sequential prediction of stationary time series

We present simple procedures for the prediction of a real valued sequence. The algorithms are based on a combinationof several simple predictors. We show that if the sequence is a realization of a bounded stationary and ergodic random process then the average of squared errors converges, almost surely, to that of the optimum, given by the Bayes predictor. We offer an analog result for the prediction of stationary gaussian processes.

Credit lines: The other side of corporate liquidity

In this paper we offer the first large sample evidence on the availability and usage ofcredit lines in U.S. public corporations and use it to re-examine the existing findings oncorporate liquidity. We show that the availability of credit lines is widespread and thataverage undrawn credit is of the same order of magnitude as cash holdings. We test thetrade-off theory of liquidity according to which firms target an optimum level of liquidity,computed as the sum of cash and undrawn credit lines. We provide support for the existenceof a liquidity target, but also show that the reasons why firms hold cash and credit linesare very different. While the precautionary motive explains well cash holdings, the optimumlevel of credit lines appears to be driven by the restrictions imposed by the credit line itself,in terms of stated purpose and covenants. In support to these findings, credit line drawdownsare associated with capital expenditures, acquisitions, and working capital.