http://upcommons.upc.edu:80/handle/123456789/6 http://upcommons.upc.edu/e-prints Wed, 16 May 2012 16:01:58 GMT 2012-05-16T16:01:58Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://upcommons.upc.edu:80/handle/2117/6532 Title: Boosting the chances to imporve stroke treatment Authors: Cobo Valeri, Erik; Secades, Julio; Miras, Francesc; González, José Antonio; Saver, Jeffrey L.; Corchero García, Cristina; Rius, Roser; Dávalos, Antoni Description: Background and Purpose— There is a lack of agreement regarding measuring the effects of stroke treatment in clinical trials, which often relies on the dichotomized value of 1 outcome scale. Alternative analyses consist mainly of 2 strategies: use all the information from an ordinal scale and combine information from several outcome scales in a single estimate. Methods— We reanalyzed 3 outcome scales that assessed patient recovery (modified Rankin Scale, National Institutes of Health Stroke Scale, and Barthel Index). With data collected from the 1652 patients in the Citicoline pooling data analysis, we used 2 standard techniques of exploratory multivariate analysis to analyze the distances among ranks and to isolate the common and the unique information provided by each of the 3 scales. Results— The different scale values correspond to gradually different patient status, confirming that information is lost when a scale is collapsed to just 2 values, whether recovered or not. The scales shared 90.7% (95% CI, 84.5–96.9) of their information, with no individual scale contributing unique information. Conclusions— Salient stroke outcome information is lost when an ordinal scale is collapsed into fewer categories. In contrast, the full scales provide a comprehensive patient outcome estimate. Furthermore, in the context of stroke clinical trials, those scales are highly correlated, providing the rationale to pool them into a single estimate. These insights may be used to optimize the analysis of stroke trials to increase study power to detect efficacious interventions http://upcommons.upc.edu:80/handle/2117/6532 no http://upcommons.upc.edu:80/handle/2117/12362 Title: Computing the barycenter graph by means of the graph edit distance Authors: Bardaji Goikoetxea, Itziar; Ferrer Sumsi, Miquel; Sanfeliu Cortés, Alberto Description: The barycenter graph has been shown as an alternative to obtain the representative of a given set of graphs. In this paper we propose an extension of the original algorithm which makes use of the graph edit distance in conjunction with the weighted mean of a pair of graphs. Our main contribution is that we can apply the method to attributed graphs with any kind of labels in both the nodes and the edges, equipped with a distance function less constrained than in previous approaches. Experiments done on four different datasets support the validity of the method giving good approximations of the barycenter graph. http://upcommons.upc.edu:80/handle/2117/12362 no http://upcommons.upc.edu:80/handle/2117/12439 Title: Sharpening haptic inputs for teaching a manipulation skill to a robot Authors: Rozo Castañeda, Leonel; Jimenez Schlegl, Pablo; Torras, Carme Description: Gaussian mixtures-based learning algorithms are suitable strategies for trajectory learning and skill acquisition, in the context of programming by demonstration (PbD). Input streams other than visual information, as used in most applications up to date, reveal themselves as quite useful in trajectory learning experiments where visual sources are not available. In this work we have used force/torque feedback through a haptic device for teaching a teleoperated robot to empty a rigid container. Structure vibrations and container inertia appeared to considerably disrupt the sensing process, so a filtering algorithm had to be devised. Moreover, some input variables seemed much more relevant to the particular task to be learned than others, which lead us to analyze the training data in order to select those relevant features through principal component analysis and a mutual information criterion. Then, a batch version of GMM/GMR [1], [2] was implemented using different training datasets (original, pre-processed data through PCA and MI). Tests where the teacher was instructed to follow a strategy compared to others where he was not lead to useful conclusions that permit devising the new research stages. http://upcommons.upc.edu:80/handle/2117/12439 no http://upcommons.upc.edu:80/handle/2117/9652 Title: On the semantics of redefinition, specialization and subsetting of associations in UML (extended version) Authors: Costal Costa, Dolors; Gómez Seoane, Cristina; Nieto Soler, Pilar Description: The definition of the exact meaning of conceptual modeling concepts is considered a relevant issue since it enhances their effective and appropriate use by designers and facilitates the automatic processing of the models where they are included. Three related concepts that permit to improve the definition of an association in UML and which still lack of a formal semantic definition are: association redefinition, association specialization and association subsetting. This paper formalizes their semantics and points out the similarities and differences that exist among them. The formalization we propose is based on the meta-modelling approach and a semantic domain composed of a set of basic UML concepts and OCL expressions, which have a previous formal definition in the literature and which are well-understood. http://upcommons.upc.edu:80/handle/2117/9652 no http://upcommons.upc.edu:80/handle/2117/12369 Title: Development of the conceptual schema of the osTicket system by applying TDCM Authors: Tort Pugibet, Albert Description: This document reports a case study application of Test-Driven Conceptual Modeling (TDCM) in the reverse engineering development of the conceptual schema of a well-known, open-source and widely-used online support system called osTicket. http://upcommons.upc.edu:80/handle/2117/12369 no http://upcommons.upc.edu:80/handle/2117/11196 Title: Development of the conceptual schema of a bowling game system by applying TDCM Authors: Tort Pugibet, Albert Description: We report a case study application of Test-Driven Conceptual Modeling (TDCM) in the development of the conceptual schema of a bowling game system, which has been used in the literature to describe in practice the use of Test-Driven Development (TDD) in the programming field. http://upcommons.upc.edu:80/handle/2117/11196 no http://upcommons.upc.edu:80/handle/2117/12367 Title: Estudio de los factores asociados a la pérdida de densidad mineral ósea en pacientes infectados con VIH Authors: Figueras-Balsells, M; Pérez-Alvaréz, N.; Negredo, Eugènia; Estany, C.; Bonjoch, A.; Gómez Melis, Guadalupe http://upcommons.upc.edu:80/handle/2117/12367 no http://upcommons.upc.edu:80/handle/2117/12146 Title: Characterisation of fuel cell state using Electrochemical Impedance Spectroscopy analysis Authors: Primucci, Mauricio Ariel; Ferrer Arnau, Luis Jorge; Serra, Maria; Riera, Jordi http://upcommons.upc.edu:80/handle/2117/12146 no http://upcommons.upc.edu:80/handle/2117/7982 Title: Customization of an agent-based medical system Authors: Batet, Montserrat; Martínez, Sergio; Valls Mateu, Aïda; Gibert Oliveras, Karina Description: In this paper, the automatic customization of an agent-based medical system is approached by means of ontologies. The particular case of Home Care studied and developed in the EU K4Care project, is presented. The customization is achieved by means of generating individual versions of a reference ontology, called Actor Profile Ontology, which defines the behaviour of the actors in the multi-agent system. The paper, analyses the usability and advantages of this customization in order to add flexibility and adaptability to the system. It also shows how the personalized ontology is able to represent the liabilities and permissions of a particular user, providing the base for automatically generating the behaviour of the corresponding personal agent. A tool, called ATAPO, is also presented. It has been designed to assist the user in the personalization process. The way how this tool interacts with the system to permit the online modification of the behaviour of the agents is also discussed. http://upcommons.upc.edu:80/handle/2117/7982 no http://upcommons.upc.edu:80/handle/2117/8203 Title: Knowledge discovery about quality of life changes of spinal cord injury patients: clustering based on rules by states Authors: Gibert Oliveras, Karina; García Rudolph, A.; Curcoll, Lluïsa; Soler, Dolors; Pla, Laura; Tormos, José Maria Description: In this paper, an integral Knowledge Discovery Methodology, named Clustering based on rules by States, which incorporates artificial intelligence (AI) and statistical methods as well as interpretation-oriented tools, is used for extracting knowledge patterns about the evolution over time of the Quality of Life (QoL) of patients with Spinal Cord Injury. The methodology incorporates the interaction with experts as a crucial element with the clustering methodology to guarantee usefulness of the results. Four typical patterns are discovered by taking into account prior expert knowledge. Several hypotheses are elaborated about the reasons for psychological distress or decreases in QoL of patients over time. The knowledge discovery from data (KDD) approach turns out, once again, to be a suitable formal framework for handling multidimensional complexity of the health domains. http://upcommons.upc.edu:80/handle/2117/8203 no http://upcommons.upc.edu:80/handle/2117/9751 Title: Integrating clinicians, knowledge and data: expert-based cooperative analysis in healthcare decision support Authors: Gibert Oliveras, Karina; García Alonso, Carlos; Salvador Carulla, Luis Description: Background: Decision support in health systems is a highly difficult task, due to the inherent complexity of the process and structures involved. Method: This paper introduces a new hybrid methodology Expert-based Cooperative Analysis (EbCA), which incorporates explicit prior expert knowledge in data analysis methods, and elicits implicit or tacit expert knowledge(IK) to improve decision support in healthcare systems. EbCA has been applied to two different case studies, showing its usability and versatility: 1) Bench-marking of small mental health areas based on technical efficiency estimated by EbCA-Data Envelopment Analysis (EbCA-DEA), and 2) Case-mix of schizophrenia based on functional dependency using Clustering Based on Rules (ClBR). In both cases comparisons towards classical procedures using qualitative explicit prior knowledge were made. Bayesian predictive validity measures were used for comparison with expert panels results. Overall agreement was tested by Intraclass Correlation Coefficient in case “1” and kappa in both cases. Results: EbCA is a new methodology composed by 6 steps: 1) Data collection and data preparation; 2) acquisition of “Prior Expert Knowledge” (PEK) and design of the “Prior Knowledge Base” (PKB); 3) PKB-guided analysis; 4) support-interpretation tools to evaluate results and detect inconsistencies (here Implicit Knowledg -IK- might be elicited); 5) incorporation of elicited IK in PKB and repeat till a satisfactory solution; 6) post-processing results for decision support. EbCA has been useful for incorporating PEK in two different analysis methods (DEA and Clustering), applied respectively to assess technical efficiency of small mental health areas and for case-mix of schizophrenia based on functional dependency. Differences in results obtained with classical approaches were mainly related to the IK which could be elicited by using EbCA and had major implications for the decision making in both cases. Discussion: This paper presents EbCA and shows the convenience of completing classical data analysis with PEK as a mean to extract relevant knowledge in complex health domains. One of the major benefits of EbCA is iterative elicitation of IK. Both explicit and tacit or implicit expert knowledge are critical to guide the scientific analysis of very complex decisional problems as those found in health system research. http://upcommons.upc.edu:80/handle/2117/9751 no http://upcommons.upc.edu:80/handle/2117/12484 Title: Ampliació del CEIP Montgat (3a fase). Localització: Montgat, Barcelona Authors: Fort Mir, Josep Maria http://upcommons.upc.edu:80/handle/2117/12484 no http://upcommons.upc.edu:80/handle/2117/12811 Title: An eddy-current-based sensor for preventing knots in metallic wire drawing processes Authors: Esteban Dalmau, Bernat; Riba Ruiz, Jordi Roger; Baquero Armans, Grau Description: During metallic wire drawing processes, the presence of knots and the failure to detect them can lead to long production interruptions, significant economic losses and a lower quality of final product. Consequently, there is a pressing need to develop methods for real-time detection and prevention of this fault. In this paper, a sensor to prevent the formation of knots during the metallic wire drawing process is presented and evaluated by means of experimental data. This fast, inexpensive, non-contact sensor is based on electromagnetic principles such as eddy current induction, magnetic reluctance variations and magnetic coupling. The proposed sensor without direct contact can detect knots in a target metallic wire by measuring the impedance variations of a calibrated sensing coil caused by either a knot or an unwound loop rising from a wire rod. The incorporation of this type of sensor into a wire-drawing machine can avoid the tightening of the knot, thereby reducing downtime and increasing the security and reliability of the process. Experiments were conducted using a scale model of the above proposed system. This allowed highlighting the sensor’s potential by carrying out an automatic, real-time knot detection during steel wire drawing http://upcommons.upc.edu:80/handle/2117/12811 no http://upcommons.upc.edu:80/handle/2117/12810 Title: Diversity ranking for video retrieval from a broadcaster archive Authors: Giró Nieto, Xavier; Alfaro Vendrell, Mónica; Marqués Acosta, Fernando Description: Video retrieval through text queries is a very common practice in broadcaster archives. The query keywords are compared to the metadata labels that documentalists have previously associated to the video assets. This paper focuses on a ranking strategy to obtain more relevant keyframes among the top hits of the results ranked lists but, at the same time, keeping a diversity of video assets. Previous solutions based on a random walk over a visual similarity graph have been modi ed to increase the asset diversity by ltering the edges between keyframes depending on their asset. The random walk algorithm is applied separately for ever visual feature to avoid any normalization issue between visual similarity metrics. Finally, this work evaluates performance with two separate metrics: the relevance is measured by the Average Precision and the diversity is assessed by the Average Diversity, a new metric presented in this work. http://upcommons.upc.edu:80/handle/2117/12810 no http://upcommons.upc.edu:80/handle/2117/12808 Title: Listening to the Deep: Live monitoring of ocean noise and cetacean acoustic signals Authors: André, Michel; Van der Schaar, Mike Connor Roger Malcolm; Zaugg, Serge Alain; Houégnigan, Ludwig; Sánchez, A.M.; Castell, Joan Description: The development and broad use of passive acoustic monitoring techniques have the potential to help assessing the large-scale influence of artificial noise on marine organisms and ecosystems. Deep-sea observatories have the potential to play a key role in understanding these recent acoustic changes. LIDO(Listening to the Deep Ocean Environment) is an international project that is allowing the real-time longterm monitoring of marine ambient noise as well as marine mammal sounds at cabled and standalone observatories. Here, we present the overall development of the project and the use of passive acoustic monitoring (PAM) techniques to provide the scientific community with real-time data at large spatial and temporal scales. Special attention is given to the extraction and identification of high frequency cetacean echolocation signals given the relevance of detecting target species, e.g. beaked whales, in mitigation processes, e.g. during military exercises. http://upcommons.upc.edu:80/handle/2117/12808 no