Xavier Pérez

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This thesis takes a machine learning approach to the general problem of recognizing phrases in a sentence. This general problem instantiates in many disambiguation tasks of Natural Language Processing, such as Shallow Syntactic Parsing, Clause Identification, Named Entity Extraction or Semantic Role Labeling. In all of them, a sentence has to be segmented(More)
We show for an arbitrary lp norm that the property that a random geometric graph G(n, r) contains a Hamiltonian cycle exhibits a sharp threshold at r = r(n) = √ log n αpn , where αp is the area of the unit disk in the lp norm. The proof is constructive and yields a linear time algorithm for finding a Hamiltonian cycle of G(n, r) a.a.s., provided r = r(n) ≥
OBJECTIVE Temozolomide is a novel oral alkylating agent, active against metastatic melanoma. Combinations of chemotherapy and biological response modifiers have been associated with increased antitumour activity. A multicentre phase II study was performed to assess the activity and toxicity of temozolomide in combination with interferon alpha-2b. PATIENTS(More)
In this paper, we propose DIME (DIffServ MAC Extension), an extension of the IEEE 802.11 MAC protocol to support Differentiated Services. The proposed extension consists of two optional modules: the Expedited Forwarding (EF) and the Assured Forwarding (AF). The Expedited Forwarding extension (DIMEEF) reuses the Interframe space of the Point Coordination(More)
We present a model of the establishment and maintenance of communication between mobile agents. We assume that the agents move through a fixed environment modeled by a motion graph and are able to communicate if they are within distance at most d of each other. As the agents move randomly, we analyze the evolution in time of the connectivity between a set(More)
PURPOSE To assess the long-term efficacy and toxicity of front-line cisplatin-based chemotherapy in patients with stage IIA or IIB testicular seminoma. PATIENTS AND METHODS Untreated patients with pure seminoma of the testis after orchiectomy, with clinical stage IIA or IIB, were considered eligible for this prospective observational study. Chemotherapy(More)
INTRODUCTION : In recurrent ovarian cancer, CA-125 could be the only objective response criteria. This study analyzes response patterns regarding CA-125 in responders versus nonresponders and determines whether a specific cutoff value for CA-125 could predict clinical response, compared with response evaluation criteria in solid tumors, in patients(More)
OBJECTIVE To compare the diagnostic accuracy of PET/CT with (18)F-FDG and (11)C-choline for early detection and localization of recurrent prostate cancer. MATERIAL AND METHODS Thirty-eight patients with increased PSA levels (0.8-9.5 ng/ml) after radical treatment for prostate cancer (surgery n = 20/radiation therapy n = 18) were included. Ten patients(More)
The aim of this study was to determine the safety and feasibility profile of paclitaxel (PTX) and docetaxel (DTX) in combination and the pharmacokinetic and pharmacodynamic interaction between these two drugs in two different alternated sequences of administration. The starting dose was PTX (100 mg/m(2)) as a 3-h IV infusion followed by DTX (50 mg/m(2)) as(More)