Possible solution of some essential zero problems in compositional data analysis

One of the tantalising remaining problems in compositional data analysis lies in how to deal with data sets in which there are components which are essential zeros. By anessential zero we mean a component which is truly zero, not something recorded as zero simply because the experimental design or the measuring instrument has not been sufficiently sensitive to detect a trace of the part. Such essential zeros occur inmany compositional situations, such as household budget patterns, time budgets,palaeontological zonation studies, ecological abundance studies. Devices such as nonzero replacement and amalgamation are almost invariably ad hoc and unsuccessful insuch situations. From consideration of such examples it seems sensible to build up amodel in two stages, the first determining where the zeros will occur and the secondhow the unit available is distributed among the non-zero parts. In this paper we suggest two such models, an independent binomial conditional logistic normal model and a hierarchical dependent binomial conditional logistic normal model. The compositional data in such modelling consist of an incidence matrix and a conditional compositional matrix. Interesting statistical problems arise, such as the question of estimability of parameters, the nature of the computational process for the estimation of both the incidence and compositional parameters caused by the complexity of the subcompositional structure, the formation of meaningful hypotheses, and the devising of suitable testing methodology within a lattice of such essential zero-compositional hypotheses. The methodology is illustrated by application to both simulated and real compositional data

The Coherence of the European Foreign Policy: A Real Barrier or an Academic Term?

The purpose of the present study is to break down, in a general and summarised way, the concept of the coherence of the European Foreign Policy, in order to analyse its meaning, its scope and its implications. This focus on coherence will be specifically dealt with upon the analysis of the impact of this phenomenon on single institutional framework, as defined by the Treaty on European Union.

A distributed environment for virtual and/or real experiments for underwater robots

This paper presents the distributed environment for virtual and/or real experiments for underwater robots (DEVRE). This environment is composed of a set of processes running on a local area network composed of three sites: 1) the onboard AUV computer; 2) a surface computer used as human-machine interface (HMI); and 3) a computer used for simulating the vehicle dynamics and representing the virtual world. The HMI can be transparently linked to the real sensors and actuators dealing with a real mission. It can also be linked with virtual sensors and virtual actuators, dealing with a virtual mission. The aim of DEVRE is to assist engineers during the software development and testing in the lab prior to real experiments

When zero doesn't mean it and other geomathematical mischief

There is almost not a case in exploration geology, where the studied data doesn’tincludes below detection limits and/or zero values, and since most of the geological dataresponds to lognormal distributions, these “zero data” represent a mathematicalchallenge for the interpretation.We need to start by recognizing that there are zero values in geology. For example theamount of quartz in a foyaite (nepheline syenite) is zero, since quartz cannot co-existswith nepheline. Another common essential zero is a North azimuth, however we canalways change that zero for the value of 360°. These are known as “Essential zeros”, butwhat can we do with “Rounded zeros” that are the result of below the detection limit ofthe equipment?Amalgamation, e.g. adding Na2O and K2O, as total alkalis is a solution, but sometimeswe need to differentiate between a sodic and a potassic alteration. Pre-classification intogroups requires a good knowledge of the distribution of the data and the geochemicalcharacteristics of the groups which is not always available. Considering the zero valuesequal to the limit of detection of the used equipment will generate spuriousdistributions, especially in ternary diagrams. Same situation will occur if we replace thezero values by a small amount using non-parametric or parametric techniques(imputation).The method that we are proposing takes into consideration the well known relationshipsbetween some elements. For example, in copper porphyry deposits, there is always agood direct correlation between the copper values and the molybdenum ones, but whilecopper will always be above the limit of detection, many of the molybdenum values willbe “rounded zeros”. So, we will take the lower quartile of the real molybdenum valuesand establish a regression equation with copper, and then we will estimate the“rounded” zero values of molybdenum by their corresponding copper values.The method could be applied to any type of data, provided we establish first theircorrelation dependency.One of the main advantages of this method is that we do not obtain a fixed value for the“rounded zeros”, but one that depends on the value of the other variable.Key words: compositional data analysis, treatment of zeros, essential zeros, roundedzeros, correlation dependency

Localització i control en temps real de PDA's basades en Windows Mobile mitjançant el sistema GPS

Desenvolupament d'un sistema consistent en un software per la recopilació de dades GPS per a Windows Mobile, un servidor de comunicacions, un server web i una plana web de consulta de les posicions en temps real de les PDA's.

Linux com a sistema operatiu de temps real

Avaluació de les capacitats d'assolir requeriments de temps real de la línia principal de nucli de Linux.

How did the Financial Crisis affect the Real Interest Rate Dynamics in Europe?

We investigate the effects of the financial crisis on the stationarity of real interest rates in the Euro Area. We use a new unit root test developed by Peseran et al. (2013) that allows for multiple unobserved factors in a panel set up. Our results suggest that while short-term and long-term real interest rates were stationary before the financial crisis, they became nonstationary during the crisis period likely due to persistent risk that characterized financial markets during that time. JEL codes: E43, C23. Keywords: Real interest rates, Euro Area, financial crisis, panel unit root tests, cross-sectional dependence.

Probabilistically analysable real-time systems (PROARTIS)

Critical real-time ebedded (CRTE) Systems require safe and tight worst-case execution time (WCET) estimations to provide required safety levels and keep costs low. However, CRTE Systems require increasing performance to satisfy performance needs of existing and new features. Such performance can be only achieved by means of more agressive hardware architectures, which are much harder to analyze from a WCET perspective. The main features considered include cache memòries and multi-core processors.Thus, althoug such features provide higher performance, corrent WCET analysis methods are unable to provide tight WCET estimations. In fact, WCET estimations become worse than for simple rand less powerful hardware. The main reason is the fact that hardware behavior is deterministic but unknown and, therefore, the worst-case behavior must be assumed most of the time, leading to large WCET estimations. The purpose of this project is developing new hardware designs together with WCET analysis tools able to provide tight and safe WCET estimations. In order to do so, those pieces of hardware whose behavior is not easily analyzable due to lack of accurate information during WCET analysis will be enhanced to produce a probabilistically analyzable behavior. Thus, even if the worst-case behavior cannot be removed, its probabilty can be bounded, and hence, a safe and tight WCET can be provided for a particular safety level in line with the safety levels of the remaining components of the system. During the first year the project we have developed molt of the evaluation infraestructure as well as the techniques hardware techniques to analyze cache memories. During the second year those techniques have been evaluated, and new purely-softwar techniques have been developed.

Market rewards to patterns on increasing earnings: do cash flow patterns, accruals manipulation and real activities manipulation matter?

This study explores whether firms have differential price-earnings multiples associated with their means of achieving a sequential pattern of increasing positive earnings. Our main findings show that market participants assign higher price-earnings multiples to firms when their pattern of increasing earnings is supported by the same pattern of increasing cash flows. Market participants assign lower price-earnings multiples to firms suspect of having engaged in accrual-based earnings management, sales manipulation, and overproduction to achieve the earnings pattern. We find, however, that market participants do not penalize firms suspect of having achieved the earnings pattern through the opportunistic reduction of discretionary expenses.

Experiències amb interacció de cos sencer generades en temps real amb entorns d’aigua virtual

L’objectiu d’aquest projecte ha estat la realització de dues aplicacions independents entre elles la interacció de les quals és a temps real i a cos sencer. En una aplicació l’usuari se li dona la possibilitat de, mitjançant el seu propi cos, transformar gotes que cauen en forma de plujavirtual en diferents flocs de neu. En la segona aplicació l’usuari pot generar onades en una superfície “aquosa”.Les dues aplicacions s’han creat amb la finalitat que puguin ser instal·lades i exposades en el centre de visitants de l’Expo2008 a Saragossa. Aquest fet ha estat fonamental per la tria de la temàtica de les aplicacions.Per assolir aquest objectiu, des del punt de vista del projectista, diferents estudis s’han hagut de portar terme. S’han realitzat estudis per tal de saber el funcionament del sistema de càmeres i del seu calibratge i de com es capta la informació referent a l’usuari. Aquestes parts són fonamentals per tal de poder gestionar bé la interacció i, sense les quals, no seria possible eldesenvolupament de les experiències. Un altre tipus d’estudi és el de la interacció, que és el que condueix l’eix principal del projecte, i el de la generació d’efectes visuals gràfics.

SIIMTA, Sistema Integrat d’Interacció de cos sencer generada en temps real i MusicoTeràpia per a persones amb discapacitats com l’Autisme

L’objectiu d’aquest Projecte Final de Carrera és el poder desenvolupar una nova eina de treball, segons el paradigme de l’interacció a cos sencer, per als terapeutes de la Fundació Tekhnikós, per a poder afavorir nous processos d’expressió, comunicació i interactivitat entre elpacient i el terapeuta en les sessions de Musicoteràpia.El Projecte tracta d’un sistema d’interacció a cos sencer per a pacients amb diferentspatologies o síndromes de conducta. Mitjançant un sistema de captura que treballa en el camp dels infrarojos, el pacient és capaç d’interactuar amb els elements de l’aplicació a través de lagesticulació. El moviment d’aquestes partícules (vegis el Glossari de termes en l’Annexe)generarà diferents sons segons posició i direcció en l’espai de la pantalla motivant al pacient a explorar el comportament el sistema de diferents maneres. Aquests estímuls sonors estan basatsen l’experiència prèvia de la Fundació amb les seves sessions de Musitoràpia, basades enl’observació de les reaccions del pacient davant estímuls sonors. Aquesta eina permetràexperimentat tot un món nou d’estímuls per al pacient, tant sonors, com visuals gràcies a la possibilitat de configuració de molts dels paràmetres del sistema. Gràcies al sistema de visió artifical s’aconsegueix una interacció màquina / pacient a cos sencer no intrusiu, molt interessant tenint en compte que l’aplicació està destinada a un gran espectre de patologies o síndromes. A més tenint en compte la tipologia general del pacient s’haoptat per una estètica molt minimalista, evitant qualsevol referència icònica per tal de no sobre estimular al pacient abans de que pugui interactuar amb el sistema.