Papers by José Beleza Moreira
The concept of data fingerprinting is of paramount importance in the frameworkof digital content ... more The concept of data fingerprinting is of paramount importance in the frameworkof digital content distribution. This project deals with fingerprintingcodes, which are used to prevent dishonest users from redistributing copyrightedmaterial. After introducing some basic notions of coding and fingerprintingtheory, the project is divided in two parts.In the first part, we present and analyze some of the main existing fingerprintingcodes and we also discuss some new constructions. The study isspecifically focused on the estimation of the minimum length of the codes,given the design parameters of the system: number of users to allocate, maximumsize of the collusions and probability of identification error. Also, wepresent some theoretical results about the new code construction studied.Finally, we present several simulations, comparing the different codes andestimating what is the minimum-length code in each region.The second part of the project is devoted to the study of the properties of...
The representation of moving objects in spatial database systems has become an important research... more The representation of moving objects in spatial database systems has become an important research topic in recent years. As it is not realistic to track and store the location of objects at every time instant, one of the issues in this domain has to do with handling uncertainty in the location of moving objects. In this paper, we propose three statistical methods for computing probabilistic estimates about the location of a moving object at a certain time and show how to use them for evaluating probabilistic range queries. The focus is on applications dealing with the spatiotemporal behavior of non-network constrained moving objects, for monitoring or data-mining purposes, for instance.
2005 International Conference on Dependable Systems and Networks (DSN'05), 2005
The growing computational and storage needs of several scientific applications mandate the deploy... more The growing computational and storage needs of several scientific applications mandate the deployment of extremescale parallel machines, such as IBM's BlueGene/L which can accommodate as many as 128K processors. In this paper, we present our experiences in collecting and filtering error event logs from a 8192 processor BlueGene/L prototype at IBM Rochester, which is currently ranked #8 in the Top-500 list. We analyze the logs collected from this machine over a period of 84 days starting from August 26, 2004. We perform a three-step filtering algorithm on these logs: extracting and categorizing failure events; temporal filtering to remove duplicate reports from the same location; and finally coalescing failure reports of the same error across different locations. Using this approach, we can substantially compress these logs, removing over 99.96% of the 828,387 original entries, and more accurately portray the failure occurrences on this system.
PLOS ONE, 2015
Metabolic syndrome is a cluster of metabolic risk factors such as obesity, diabetes and cardiovas... more Metabolic syndrome is a cluster of metabolic risk factors such as obesity, diabetes and cardiovascular diseases. Mitochondria is the main site of ATP production and its dysfunction leads to decreased oxidative phosphorylation, resulting in lipid accumulation and insulin resistance. Our group has demonstrated that kinins can modulate glucose and lipid metabolism as well as skeletal muscle mass. By using B2 receptor knockout mice (B2R -/-) we investigated whether kinin action affects weight gain and physical performance of the animals. Our results show that B2R -/mice are resistant to high fat diet-induced obesity, have higher glucose tolerance as well as increased mitochondrial mass. These features are accompanied by higher energy expenditure and a lower feed efficiency associated with an increase in the proportion of type I fibers and intermediary fibers characterized by higher mitochondrial content and increased expression of genes related to oxidative metabolism. Additionally, the increased percentage of oxidative skeletal muscle fibers and mitochondrial apparatus in B2R -/mice is coupled with a higher aerobic exercise performance. Taken together, our data give support to the involvement of kinins in skeletal muscle fiber type distribution and muscle metabolism, which ultimately protects against fat-induced obesity and improves aerobic exercise performance.
The ranking of geographically referenced objects based on the amenities in their neighborhood has... more The ranking of geographically referenced objects based on the amenities in their neighborhood has been recently addressed in [2, 3]. These works present a methodology to specify queries using spatial and nonspatial features to compute an overall score for the given objects. The spatial features considered are the location of the objects to be ranked and the location of the amenities in their neighborhood. The non-spatial features are categories of amenities and ratings disclosed by rating providers. This work applies this methodology to score the administrative regions of Aveiro considering a set of features that are relevant to the implementation of decision support systems in the real-estate market. The aim is to find out the spots that may be more interesting to buy or rent a house taking into account the accessibility to living amenities in urban areas.
This chapter deals with several important issues pe rtaining to the management,of moving,objects ... more This chapter deals with several important issues pe rtaining to the management,of moving,objects datasets in databases. The design of representative benchmarks is closely related to the formal characterization of t he properties (that is, distribution, speed, nature of movement) of these datasets; uncertainty is another important aspect that conditions the accuracy of the representation and therefore the confidence in
Medicine & Science in Sports & Exercise, 2015
Exercise training reduces pathological remodeling and improves cardiac function in ischemic heart... more Exercise training reduces pathological remodeling and improves cardiac function in ischemic heart failure, however, causal mechanisms underlying the cardiac benefits of exercise are poorly understood. Since opening of ATP-sensitive K (KATP) channels protects the heart during myocardial stress, we hypothesized that such a mechanism is responsible for some of the cardiac benefits induced by exercise in postinfarction chronic heart failure (CHF). Left ventricular myocytes were isolated from three groups of rats: Sham, CHF Tr (4 weeks after myocardial infarction, rats underwent 8 weeks of aerobic interval training, 5 days/week) and CHF Sed (rats sedentary for 12 weeks following infarction). Cardiomyocyte survival after oxidative stress exposure (200 μM H2O2) and calcium handling (cells loaded with Fura-2 AM and electrically paced at 1 Hz) were assessed in the presence of KATP channel inhibitor glibenclamide. Expression of KATP subunits (SUR2A and Kir6.2) was evaluated using immunoblotting. Exercise improved cardiac function in CHF Tr animals. Cardiomyocytes from CHF Sed rats were more susceptible to oxidative stress-induced cell death than CHF Tr and Sham cardiomyocytes, with glibenclamide completely abolishing the protective effect of exercise. Glibenclamide did not affect cardiomyocyte survival in Sham or CHF Sed rats. Also, exercise increased the systolic Ca transient amplitude and improved diastolic Ca removal in CHF Tr cardiomyocytes (compared to CHF Sed); both significantly attenuated by glibenclamide. Exercise resulted in increased expression of KATP channel subunits in CHF Tr hearts with a more pronounced and significant effect on SUR2A. Our data suggest that KATP channel upregulation induced by chronic exercise likely mediates some of exercise-induced beneficial effects on cardiac function in postischemic heart failure.
Proceedings of the 14th international conference on Supercomputing - ICS '00, 2000
Scheduling of processes onto processors of a parallel machine has always been an important and ch... more Scheduling of processes onto processors of a parallel machine has always been an important and challenging area of research. The issue becomes even more crucial and di cult as we gradually progress to the use of o -the-shelf workstations, operating systems, and high bandwidth networks to build cost-e ective clusters for demanding applications. Clusters are gaining acceptance not just in scienti c applications that need supercomputing power, but also in domains such as databases, web service and multimedia, which place diverse Quality-of-Service QoS demands on the underlying system. Further, these applications have diverse characteristics in terms of their computation, communication and I O requirements, making conventional parallel scheduling solutions, such as space sharing or coscheduling, an unattractive option. At the same time, leaving it to the native operating system of each node to make decisions independently can lead to ine ective use of system resources whenever there is communication. Instead, an emerging class of dynamic coscheduling mechanisms, that attempt to take remedial actions to guide the system towards coscheduled execution without requiring explicit synchronization, o er a lot of promise for cluster scheduling. Using a detailed simulator, this paper evaluates the pros and cons of di erent dynamic coscheduling alternatives, while comparing their advantages over traditional coscheduling and not performing any coordinated scheduling at all. The impact of dynamic job arrivals, job characteristics and di erent system parameters on these alternatives are evaluated in terms of several performance criteria.
ACM/IEEE SC 2006 Conference (SC'06), 2006
Mapping virtual processes onto physical processos is one of the most important issues in parallel... more Mapping virtual processes onto physical processos is one of the most important issues in parallel computing. The problem of mapping of processes/tasks onto processors is equivalent to the graph embedding problem which has been studied extensively. Although many techniques have been proposed for embeddings of two-dimensional grids, hypercubes, etc., there are few efforts on embeddings of three-dimensional grids and tori. Motivated for better support of task mapping for Blue Gene/L supercomputer, in this paper, we present embedding and integration techniques for the embeddings of three-dimensional grids and tori. The topology mapping library that based on such techniques generates high-quality embeddings of two/three-dimensional grids/tori. In addition, the library is used in BG/L MPI library for scalable support of MPI topology functions. With extensive empirical studies on large scale systems against popular benchmarks and real applications, we demonstrate that the library can significantly improve the communication performance and the scalability of applications.
The dialectic method proposes a two-way teaching (teacher-student) that causes learning through o... more The dialectic method proposes a two-way teaching (teacher-student) that causes learning through ongoing task of the subjects. For this, the teacher assumes the role of mediator and directs several activities. In line with the above, Exercise Physiology is an academically oriented discipline undergoing in a dynamic environment, and the use of different teaching strategies is needed to optimize the appropriation of knowledge in an active way and contribute to the greater autonomy of university students. Therefore, the aim of this study was apply different strategies in the course entitled "Physiology of the Motor Activity I" at School of Physical Education and Sport of University of Sao Paulo and assess a correlation between students participation and students performance. We used teaching strategies such as exposition and dialogue classes, practical classes, conversations with experts, directed study, study of scientific texts, concept mapping, case study and study of the e...
Proceedings of the 7th workshop on Workshop on languages, compilers, and run-time support for scalable systems - LCR '04, 2004
In this paper, we show our initial experience with a class of objects, called Hierarchically Tile... more In this paper, we show our initial experience with a class of objects, called Hierarchically Tiled Arrays (HTAs), that encapsulate parallelism. HTAs allow the construction of single-threaded parallel programs where a master process distributes tasks to be executed by a collection of servers holding the components (tiles) of the HTAs. The tiled and recursive nature of HTAs facilitates the adaptation of the programs that use them to varying machine configurations, and eases the mapping of data and tasks to parallel computers with a hierarchical organization. We have implemented HTAs as a MATLAB TM toolbox, overloading conventional operators and array functions such that HTA operations appear to the programmer as extensions of MATLAB TM . Our experiments show that the resulting environment is ideal for the prototyping of parallel algorithms and greatly improves the ease of development of parallel programs while providing reasonable performance.
ACM/IEEE SC 2006 Conference (SC'06), 2006
This paper discusses the design and implementation of a onesided communication interface for the ... more This paper discusses the design and implementation of a onesided communication interface for the IBM Blue Gene/L supercomputer. This interface facilitates ARMCI and the Global Arrays toolkit and can be used by other one-sided communication libraries. New protocols, interrupt driven communication, and compute node kernel enhancements were required to enable these libraries. Three possible methods for enabling ARMCI on the Blue Gene/L software stack are discussed. A detailed look into the development process shows how the implementation of the one-sided communication interface was completed. This was accomplished on a compressed time scale with the collaboration of various organizations within IBM and open source communities. In addition to enabling the one-sided libraries, bandwidth enhancements were made for communication along a diagonal on the Blue Gene/L torus network. The maximum bandwidth improved by a factor of three. This work will enable a variety of one-sided applications to run on Blue Gene/L. speed networks: a three-dimensional torus network primarily used for point-to-point operations, a global combining network used for reductions and broadcasts, and a global interrupt network used for fast synchronizations. The two cores share injection and reception First-In-First-Out (FIFO) network devices. These are the hardware level memory areas into which packets are copied for insertion into the network or reception from the network. The hardware provides the communication layers with guaranteed packet delivery.
ACM SIGAPP Applied Computing Review, 2012
This paper deals with the design and implementation of a data model and operations for dealing wi... more This paper deals with the design and implementation of a data model and operations for dealing with continuously changing spatial data in Oracle 11g object-relational DBMS. The data model relies on abstract data types but we introduce modifications to the internal structure of the spatiotemporal data representations proposed in the literature, to reduce storage requirements and to enable the reuse of data during the execution of queries. We show how to implement spatiotemporal operations relying on the spatial functions released by the underlying DBMS and how to use the alternative data representations to reduce the volume of temporary data created in the evaluation of spatiotemporal operations. We also demonstrate how to use the proposed data types and operations for storage and manipulation of moving objects data using SQL. Finally, we discuss on the advantages and disadvantages of the proposed solutions. 1
Lecture Notes in Computer Science, 2007
Clusters of loosely connected machines are becoming an important model for commercial computing. ... more Clusters of loosely connected machines are becoming an important model for commercial computing. The cost/performance ratio makes these scale-out solutions an attractive platform for a class of computational needs. The work we describe in this paper focuses on understanding performance when using a scale-out environment to run commercial workloads. We describe the novel scale-out environment we configured and the workload we ran on it. We explain the unique performance challenges faced in such an environment and the tools we applied and improved for this environment to address the challenges. We present data from the tools that proved useful in optimizing performance on our system. We discuss the lessons we learned applying and modifying existing tools to a commercial scale-out environment, and offer insights into making future performance tools effective in this environment.
Journal of Translational Medicine, 2015
Background: Activation of protein kinase AKT is required for cardioprotection by ischemic precond... more Background: Activation of protein kinase AKT is required for cardioprotection by ischemic preconditioning, and transgenic overexpression of AKT protects the heart against ischemia. However, it is unknown whether acute pharmacological activation of AKT alone, using a therapeutically relevant strategy, induces cardioprotection. In this study we provide the first evidence to clarify this question. Methods: We used a recently described specific activator of AKT, the small molecule SC79, to treat rat hearts submitted to ischemia and reperfusion. Initially, isolated rat hearts were perfused with increasing doses of SC79 to verify the magnitude of AKT activation. Low and high doses were determined and used to treat hearts submitted to ischemia (35 minutes) and reperfusion (60 minutes), in a randomized and blinded design. AKT activation was verified by western immunobloting. Metabolic profile was determined by cardiac ATP content and mitochondrial enzyme activity, while cytosolic levels of cytochrome C and caspase-3 activity were used as markers of apoptosis. Ischemic injury was assessed by quantification of infarct size and cardiac release of creatine kinase and lactate dehydrogenase. Results: SC79 activated cardiac AKT within 30 minutes in a dose-dependent fashion. ATP content was largely reduced by ischemia, but was not rescued by SC79. Similarly, mitochondrial enzyme activity was not affected by SC79. SC79 administered before ischemia or at reperfusion did not prevent cytosolic accumulation of cytochrome C and overactivation of caspase-3. Finally, SC79 failed to reduce infarct size or release of cardiac injury biomarkers at reperfusion.
2002 IEEE International Solid-State Circuits Conference. Digest of Technical Papers (Cat. No.02CH37315), 2002
Abstract System-on-a-chip technology allows a level of integration that can be leveraged to devel... more Abstract System-on-a-chip technology allows a level of integration that can be leveraged to develop inexpensive high-performance, low-power computing nodes. When used in aggregate, this approach promises to challenge conventional supercomputer architectures in the high-performance computing arena. Systems under consideration reach into the hundreds of thousand nodes per machine. Architecture for these systems are described
Proceedings of the 3rd conference on Computing frontiers - CF '06, 2006
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Papers by José Beleza Moreira