Agustín Santos

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In this paper we initiate the generalization of the Adversarial Queueing Theory (aqt) model to capture the dynamics of continuous scenarios in which the usually assumed synchronicity of the evolution is not required anymore. We propose an asynchronous model, named continuous aqt (caqt), in which packets can have arbitrary lengths, and the network links may(More)
In this work we consider a distributed system formed by a master processor and a collection of n processors (workers) that can execute tasks; worker processors are untrusted and might act maliciously. The master assigns tasks to workers to be executed. Each task returns a binary value, and we want the master to accept only correct values with high(More)
Problem and Motivation. The demand for processing large amounts of data has increased over the last decade. As traditional one-processor machines have limited computational power, distributed systems consisting of multitude of cooperating processing units are used instead. An example of such a massive distributed cooperative computation is the SETI@Home(More)
A significant amount of effort is been invested in constructing effective solutions for sentiment analysis and topic detection, but mostly for English texts. Using a corpus of Spanish tweets, we present a comparative analysis of different approaches and classification techniques for these problems.
Celiac disease (CD) is an autoimmune disorder, which damages the small intestine and is caused by ingestion of gluten in genetically susceptible individuals. The only known effective treatment is a lifelong gluten-free diet. Genetic risk factors have been identified and nearly all patients are HLA-DQ2 and/or HLA-DQ8 positive. Specific autoantibodies, IgA(More)
Ingestion of organophosphate (OP) compounds usually results in severe poisoning. We undertook a retrospective study of 52 consecutive patients admitted with severe OP poisoning to determine the value of serum cholinesterase (SChE) in monitoring clinical course. Considering survivors and non-survivors, we evaluate clinical and laboratory baseline(More)
We consider a Master-Worker distributed system where a master processor assigns, over the Internet, tasks to a collection of n workers, which are untrusted and might act maliciously. In addition, a worker may not reply to the master, or its reply may not reach the master, due to unavailabilities or failures of the worker or the network. Each task returns a(More)
OBJECTIVES To use two rapid human immunodeficiency virus (HIV) tests at labor, measure test acceptance and performance, and measure HIV prevalence in these women. METHODS Between February and October 2000, two rapid tests (Determine; Abbott, Chicago, IL, U.S.A. and Double Check; Orgenics, Yavne, Israel) were used in three public maternities in Rio de(More)
Collaboration may be understood as the execution of coordinated tasks (in the most general sense) by groups of users, who cooperate for achieving a common goal. Collaboration is a fundamental assumption and requirement for the correct operation of many communication systems. The main challenge when creating collaborative systems in a decentralized manner is(More)