A High-level strategy for C-net discovery

Causal nets have been recently proposed as a suitable model for process mining, due to their declarative semantics and compact representation. However, the discovery of causal nets from a log is a complex problem. The current algorithmic support for the discovery of causal nets comprises either fast but inaccurate methods (compromising quality), or accurate algorithms that are computational demanding, thus limiting the size of the inputs they can process. In this paper a high-level strategy is presented, which uses appropriate clustering techniques to split the log into pieces, and benefits from the additive nature of causal nets. This allows amalgamating structurally the discovered Causal net of each piece to derive a valuable model. The claims in this paper are accompanied with experimental results showing the significance of the high-level strategy presented.Postprint (published version

Amending C-net discovery algorithms

As the complexity of information systems evolves, there is a growing interest in defining suitable process models than can overcome the limitations of traditional formalisms like Petri nets or related. Causal nets may be one of such promising process models, since important characteristics of their semantics deviate from the ones in the literature. Due to their novelty, very few discovery algorithms exist for Causal nets. Moreover, the existing ones offer very few guarantees regarding the outcome produced. This paper describes an algorithm that can be applied as a second step to any discovery technique to significantly improve the quality of the final Causal net derived. We have tested the technique in combination with the existing algorithms in the literature on several benchmarks, noticing a considerable improvement in all of them.Postprint (published version

Estudi de viabilitat d’una microxarxa urbana a Badalona

El present projecte final de carrera proposa un nou model de subministrament elèctric a àrees residencials, a partir de la seva aplicació a l’Àrea Residencial Estratègica de l’Estrella, a Badalona. Aquest model se centra d’una banda en la reducció del consum energètic dels seus usuaris, mitjançant diferents estratègies de gestió de la demanda, i de l’altra en la facturació conjunta de termes de potència i energia per a tot el barri, gràcies a la contractació a mitja tensió i a centres de transformació propis gestionats localment. L’objectiu del projecte és per tant estudiar la viabilitat d’una instal·lació d’aquestes característiques, realitzant-ne el disseny i analitzant els components que seran necessaris en comparació amb una instal·lació realitzada segons la normativa marcada pel Reglament Electrotècnic de Baixa Tensió. Una comparació entre aquestes dues metodologies permetrà divisar les diferències en volums d’inversió, volums de càrrega, consum energètic i en definitiva avaluar els beneficis que aporta la nova solució tant per al sistema elèctric com per al medi ambient i la butxaca dels habitants d’un barri d’aquestes característiques. El projecte ofereix inicialment una visió global de la situació energètica actual, a mode de justificació, per a demostrar que és totalment necessari un canvi d’aquest tipus en el sistema de distribució de baixa tensió, si es vol complir amb la normativa europea referent a emissions de gasos contaminants i reducció del consum energètic. La metodologia amb la que es dissenyen actualment aquests sistemes acaba sobredimensionant àmpliament tant instal·lacions com contractes de facturació, com s’observarà en els càlculs fets per al sector residencial mencionat. L’ús de les tecnologies digitals obre la porta a una gestió més automatitzada, eficient i ràpida, i així es demostrarà en els capítols centrals del treball, mentre en els darrers es proporcionaran els resultats extrets de la instal·lació dissenyada. A partir d’una hipòtesi de participació dels consumidors en les estratègies proposades, es calcularan els beneficis anuals d’aquest sistema, els quals permeten reduir notablement el cost de la factura elèctrica de tots ells (en un percentatge variable en funció de la seva participació) mentre s’amortitza la inversió suplementària en un temps raonable. D’aquesta manera es compleixen totes les condicions necessàries per a que l’alternativa proposada sigui una eina molt útil en la lluita contra el canvi climàtic i les seves conseqüències

Desarrollo de módulos de tutorías y gestión de pagos para Dinantia

Dinantia es una aplicación orientada a facilitar, mejorar y concentrar la comunicación y la gestión de escuelas y centros educativos. Los clientes de la aplicación han solicitado la implementación de funcionalidades para la gestión de tutorías y una ampliación de las funcionalidades de pagos. Debido a esta necesidad surge este proyecto, en el que se desarrollará un módulo de gestión y reserva de tutorías y se ampliará el módulo de pagos actual, ampliando sus funcionalidades y utilidad.Dinantia is an application aimed at facilitating, improving and concentrating the communication and administration of schools and educational centers. Several clients have requested the implementation of functionalities for the management of tutor meetings and an extension of the payment features. This project arises due to this need, and it will comprise the development of the tutor meetings management and reservation module and the expansion of the current payment module, improving its functionalities and utility.Dinantia és una aplicació orientada a facilitar, millorar i concentrar la comunicació i gestió d’escoles i centres educatius. Els clients de l’aplicació han sol·licitat la implementació de funcionalitats per la gestió de tutories i una ampliació de les funcionalitats de pagaments. A causa d’aquesta necessitat sorgeix aquest projecte, en el qual es desenvoluparà un mòdul de gestió i reserva de tutories i s’ampliarà el mòdul de pagaments actual, ampliant les seves funcionalitats i utilitat

Reducing event variability in logs by clustering of word embeddings

Several business-to-business and business-to-consumer services are provided as a human-to-human conversation in which the provider representative guides the conversation towards its resolution based on her experience, following internal guidelines. Several attempts to automatize these services are becoming popular, but they are currently limited to procedures and objectives set during design step. Process discovery techniques could provide the necessary mechanisms to monitor event logs derived from textual conversations and expand the capabilities of conversational bots. Still, variability of textual messages hinders the utility of process discovery techniques by producing non-understandable unstructured process models. In this paper, we propose the usage of word embedding for combining events that have a semantically similar name.Peer ReviewedPostprint (author's final draft

Next stop 'NoOps': enabling cross-system diagnostics through graph-based composition of logs and metrics

Performing diagnostics in IT systems is an increasingly complicated task, and it is not doable in satisfactory time by even the most skillful operators. Systems and their architecture change very rapidly in response to business and user demand. Many organizations see value in the maintenance and management model of NoOps that stands for No Operations. One of the implementations of this model is a system that is maintained automatically without any human intervention. The path to NoOps involves not only precise and fast diagnostics but also reusing as much knowledge as possible after the system is reconfigured or changed. The biggest challenge is to leverage knowledge on one IT system and reuse this knowledge for diagnostics of another, different system. We propose a framework of weighted graphs which can transfer knowledge, and perform high-quality diagnostics of IT systems. We encode all possible data in a graph representation of a system state and automatically calculate weights of these graphs. Then, thanks to the evaluation of similarity between graphs, we transfer knowledge about failures from one system to another and use it for diagnostics. We successfully evaluate the proposed approach on Spark, Hadoop, Kafka and Cassandra systems.Peer ReviewedPostprint (author's final draft

Dynamic flight plan design for UAS remote sensing applications

The development of Flight Control Systems (FCS) coupled with the availability of other Commercial Off-The Shelf (COTS) components is enabling the introduction of Unmanned Aircraft Systems (UAS) into the civil market. UAS have great potential to be used in a wide variety of civil applications such as environmental applications, emergency situations, surveillance tasks and more. In general, they are specially well suited for the so-called D-cube operations (Dirty, Dull or Dangerous). Current technology greatly facilitates the construction of UAS. Sophisticated flight con- trol systems also make them accessible to end users with little aeronautical expertise. How- ever, we believe that for its successful introduction into the civil market, progress needs to be made to deliver systems able to perform a wide variety of missions with minimal reconfiguration and with reduced operational costs. Most current flight plan specification mechanisms consist in a simple list of waypoints, an approach that has important limitations. This paper proposes a new specification mech- anism with semantically richer constructs that will enable the end user to specify more complex flight plans. The proposed formalism provides means for specifying iterative be- havior, conditional branching and other constructs to dynamically adapt the flight path to mission circumstances. Collaborating with the FCS, a new module on-board the UAS will be in charge of executing these plans. This research also studies how the proposed flight plan structure can be tailored to the specific needs of remote sensing. For these type of applications well structured and efficient area and perimeter scanning is mandatory. In this paper we introduce several strategies focused to optimize the scanning process for tactical or mini UAS. The paper also presents a prototype implementation of this module and the results obtained in simulations.Postprint (published version

Edge-distance-regular graphs

Edge-distance-regularity is a concept recently introduced by the authors which is similar to that of distance-regularity, but now the graph is seen from each of its edges instead of from its vertices. More precisely, a graph Γ with adjacency matrix A is edge-distance-regular when it is distance-regular around each of its edges and with the same intersection numbers for any edge taken as a root. In this paper we study this concept, give some of its properties, such as the regularity of Γ, and derive some characterizations. In particular, it is shown that a graph is edge-distance-regular if and only if its k-incidence matrix is a polynomial of degree k in A multiplied by the (standard) incidence matrix. Also, the analogue of the spectral excess theorem for distance-regular graphs is proved, so giving a quasi-spectral characterization of edgedistance-regularity. Finally, it is shown that every nonbipartite graph which is both distance-regular and edge-distance-regular is a generalized odd graph.Preprin

Edge distance-regular graphs

* distance-regularity; * local spectra; * predistance polynomials; * the spectral excess theorem; * generalized odd graphsEdge-distance-regularity is a concept recently introduced by the authors which is similar to that of distance-regularity, but now the graph is seen from each of its edges instead of from its vertices. More precisely, a graph Γ with adjacency matrix A is edge-distance-regular when it is distance-regular around each of its edges and with the same intersection numbers for any edge taken as a root. In this paper we study this concept, give some of its properties, such as the regularity of Γ, and derive some characterizations. In particular, it is shown that a graph is edge-distance-regular if and only if its k-incidence matrix is a polynomial of degree k in A multiplied by the (standard) incidence matrix. Also, the analogue of the spectral excess theorem for distance-regular graphs is proved, so giving a quasi-spectral characterization of edge-distance-regularity. Finally, it is shown that every nonbipartite graph which is both distance-regular and edge-distance-regular is a generalized odd graph.Peer ReviewedPostprint (published version

Assessment of inner retinal layers and choroidal thickness in type 1 diabetes mellitus: a cross-sectional study

Choroid; Diabetic retinopathy; Ganglion cell layerCoroides; Retinopatía diabética; Capa de células ganglionaresCoroide; Retinopatia diabètica; Capa de cèl·lules ganglionàriesRecent studies have shown that retinal neurodegeneration may precede visible vascular changes in diabetic retinopathy (DR). In addition, the relationship of choroidal thickness (CT) with DR stage is not well defined. To assess the inner retinal and choroidal structural changes in type 1 diabetic subjects (T1D), a cross-sectional study was conducted in 242 T1D patients and in 69 age-matched, non-diabetic individuals. The nasal retinal nerve fibre layer (RNFL) thickness was lower in T1D patients without DR (p < 0.001), with mild DR (p < 0.001), and with advanced DR (p < 0.001) compared to control subjects. The ganglion cell layer (GCL) thickness was lower in T1D patients with advanced DR compared to those with mild DR (p = 0.003) and without DR (p < 0.001) and compared to the control subjects (p < 0.001). T1D subjects with no DR and mild DR had higher CT than the control subjects, but the CT in T1D patients with advanced DR was lower (p = 0.038) than that in T1D subjects with mild DR and was not significantly different from that of the control subjects. In conclusion, T1D subjects showed a significant thinning of the nasal RNFL in the early stages of the disease, even before any vascular changes in the retina. A decrease in the GCL thickness during advanced DR stages was observed. Choroidal thickness was higher in T1D subjects without DR and in early DR stages but decreased in advanced stages.This research was supported by grants from the Spanish Ministry of Health, the Carlos III National Institute of Health (PI12/0183 and PI15/0625) and the European Regional Development Fund (ERDF). CIBER for Diabetes and Associated Metabolic Diseases (CIBERDEM) is an initiative of ISCIII, Spain. The Health Sciences Research Institute Germans Trias i Pujol is part of the CERCA Programme/Generalitat de Catalunya