4,557 research outputs found
Experiments in Clustering Homogeneous XML Documents to Validate an Existing Typology
This paper presents some experiments in clustering homogeneous XMLdocuments
to validate an existing classification or more generally anorganisational
structure. Our approach integrates techniques for extracting knowledge from
documents with unsupervised classification (clustering) of documents. We focus
on the feature selection used for representing documents and its impact on the
emerging classification. We mix the selection of structured features with fine
textual selection based on syntactic characteristics.We illustrate and evaluate
this approach with a collection of Inria activity reports for the year 2003.
The objective is to cluster projects into larger groups (Themes), based on the
keywords or different chapters of these activity reports. We then compare the
results of clustering using different feature selections, with the official
theme structure used by Inria.Comment: (postprint); This version corrects a couple of errors in authors'
names in the bibliograph
: étude de cas
A partir de trois cas pris en Afrique du Nord, en Lycie et en Cisalpine, cet article examine le rôle des entrepôts maritimes dans la diffusion des marchandises en Méditerranée à l'époque romaine, notamment pour l'approvisionnement de Rome
Electrodeionization versus Electrodialysis: A Clean-Up of Produced Water in Hydraulic Fracturing
Electrodeionization (EDI) is a widely studied process ranging from applications in wastewater clean-up in the food and beverage industry to purifying organic compounds. To date, there are no apparent studies on applying this technology to produced wastewater recovered from hydraulic fracking sites. Water consumption within hydraulic fracturing sites can reach in the upwards of millions of gallons per site, so a need for a water recycling process becomes necessary within areas where water requirements are scarce. Implementation of an EDI module that is capable of handling high salt solutions from produced wastewater in subsequent fracturing practices will decrease overall water demands, making this an environmentally sustainable process as well. This study will focus on the selective removal of high concentrations of ions using ion-selective membranes and ion exchange wafers in Wafer-Enhanced Electrodeionization (WE-EDI) of hydraulic fracturing solutions for improved water recovery and reuse within industrial applications. Experiments were performed using a WE-EDI setup with varied wafer composition and thickness in comparison with electrodialysis for selective removal of divalent ions (Ca2+) over monovalent ions (Na+) from simulated and fracking solutions. Research sought to show that when increasing the wafer thickness and changing the composition (weak acid compared to strong acid resins) there would be a greater overall current efficiency observed and subsequently lower power consumption. This research concluded that there is some degree of enhanced selectivity with increased wafer size, as well as varied composition compared to a traditional ED system. Continued research is recommended to conclude uncertainties, eliminate areas of system performance error and to further solidify all hypothesises within this research
Thermal stability analysis of the fine structure of solar prominences
The linear thermal stability of a 2D periodic structure (alternatively hot and cold) in a uniform magnetic field is analyzed. The energy equation includes wave heating (assumed proportional to density), radiative cooling and both conduction parallel and orthogonal to magnetic lines. The equilibrium is perturbed at constant gas pressure. With parallel conduction only, it is found to be unstable when the length scale 1// is greater than 45 Mn. In that case, orthogonal conduction becomes important and stabilizes the structure when the length scale is smaller than 5 km. On the other hand, when the length scale is greater than 5 km, the thermal equilibrium is unstable, and the corresponding time scale is about 10,000 s: this result may be compared to observations showing that the lifetime of the fine structure of solar prominences is about one hour; consequently, our computations suggest that the size of the unresolved threads could be of the order of 10 km only
Hypothèse de restitution d'un navire à dolia: la construction d'une maquette
International audiencePrésentation de l'étude d'architecture navale nécessaire à la réalisation d'une maquette de l'épave du navire à dolia de Ladispoli : collecte des informations archéologiques, réalisation du plan de forme, construction du modèle d'étude au 1/10e. L'expérimentation compare les données recueillies sur d'autres épaves et a permis de proposer une hypothèse sur le chargement de la cargaison
X-ray structures of dinuclear copper(I) and polynuclear copper(II) complexes with the 2,4-bis(cyanamido)cyclobutane-1,3-dione dianion
From the 2,4-bis(cyanamido)cyclobutane-1,3-dione dianion (2,4-NCNsq2−), two copper complexes [Cu2(PPh3)4(PhCN)2(μ-2,4-NCNsq)] · PhCN (1) and [Cu(dien)(μ-2,4-NCNsq) · H2O]n (2) have been synthesized and characterized by IR and electronic absorption spectroscopies. Their structures have been determined by X-ray crystallography. Complex 1 is a dinuclear copper(I) compound with a 2,4-NCNsq2− ligand bridging two copper atoms through the nitrile nitrogen atoms. Complex 2 appears as a 3D network constituted of copper(II) atoms bridged by 2,4-NCNsq2− dianions. This complex presents an unexpected coordination mode of the bis(cyanamido) ligands which are both coordinated via the nitrile functions and via the amido nitrogen atoms of the NCN groups
Diagnostics and treatment in bronchial carcinoid tumors
At the start of this thesis there were several unanswered questions with regard to optimal patient selection for different treatments of bronchial carcinoid. Also, there were unanswered questions with regard to classification of bronchial carcinoid on small histological samples and with regard to prognostic value of several new tissue biomarkers. The aim of this thesis was to further optimize patient selection for parenchyma sparing techniques, and to explore the potential value of biomarkers in the treatment of bronchial carcinoid. Part one (chapter 2-5) of this thesis describes the classification of bronchial carcinoid on small histological samples and the use of diagnostic and prognostic biomarkers. In Chapter 2 we analyze patient selection for endobronchial treatment and underscore the importance of radiological assessment of bronchial carcinoids. Differentiation between typical and atypical carcinoid according to the current WHO classification is accomplished by obtaining the mitotic count and the presence of necrosis. As outlined above, TC is defined as a neuroendocrine tumour with less than 2 mitoses per 2 mm2 and absence of necrosis, while AC is defined by 2-10 mitoses per 2 mm2 and/or the presence of (dot-like) necrosis. However, it is known that small biopsies have limited diagnostic value for the distinction between TC and AC. In Chapter 3 and Chapter 4 we analyzed biopsy-resection paired specimens of patients referred for treatment for bronchial carcinoid to measure accuracy of pretreatment biopsies and analyze the value of tumor biopsy size. Furthermore, we describe the reliability of different immunohistochemical markers on different biopsies and resection specimens, and assessed the impact of specimen size on the accuracy of the diagnosis. Because the current classification of TC and AC only partially reflects their metastatic potential, there is a need for more accurate prognostic biomarkers for bronchial carcinoids. In Chapter 5 we investigated a combination of morphological and novel immunohistochemical markers for predicting dissemination. Part two (chapter 6-8) focuses on therapeutic strategies and patient selection for EBT. In Chapter 6 we present the results of a systematic review of the available literature on the feasibility and outcome of endobronchial treatment compared to surgical resection. We studied several endpoints such as overall survival, disease free survival, recurrence rate, complications, quality of life, and healthcare costs. Where EBT can be curative for patients with small intraluminal carcinoid tumors, tumor debulking prior to surgery may potentially result in less lung parenchyma that has to be removed during surgery to achieve complete resection of the tumor. In addition, EBT may reduce the need for sleeve resection to achieve radical margins when bulky tumors are removed. It is in Chapter 7 that we investigated whether endobronchial therapy for bronchial carcinoid, if not curative, can reduce the extent of the surgical resection and whether EBT prior to surgery is associated with increased surgical morbidity. Several letters, in reply to comments from experts in the field of treatment for bronchial carcinoid tumors, regarding published studies by our group, are bundled in Chapter 8
Sexual orientation and mental health: a review [Orientation sexuelle et santé mentale : une revue de la littérature ]
International audienceBACKGROUND: The aim of this paper is to review available knowledge on sexual orientation and mental health, especially for women. METHODS: Papers published in English or French, between 1997 and 2007, were selected in PubMed using the following keywords "homosexuality/sexual orientation and mental health/depression/suicide". To be retained, papers had to contain findings from quantitative surveys comparing homosexual and heterosexual adults. In all, this review analyses 22 papers including two that are based on the same survey. RESULTS: This review found a general pattern of poorer mental health for homosexuals and even more so for bisexuals compared to heterosexuals. Results are especially consistent regarding elevated risk of suicide attempts
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