Author: "Alexandru, Nica" / Language: undetermined - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Alexandru, Nica"' showing total 76 results

Start Over Author "Alexandru, Nica" Language undetermined

76 results on '"Alexandru, Nica"'

1. High potential for CH4 emission mitigation from oil infrastructure in one of EU’s major production regions

Author: Foteini Stavropoulou, Katarina Vinković, Bert Kers, Marcel de Vries, Steven van Heuven, Piotr Korbeń, Martina Schmidt, Julia Wietzel, Pawel Jagoda, Jaroslav M. Necki, Jakub Bartyzel, Hossein Maazallahi, Malika Menoud, Carina van der Veen, Sylvia Walter, Béla Tuzson, Jonas Ravelid, Randulph Paulo Morales, Lukas Emmenegger, Dominik Brunner, Michael Steiner, Arjan Hensen, Ilona Velzeboer, Pim van den Bulk, Hugo Denier van der Gon, Antonio Delre, Maklawe Essonanawe Edjabou, Charlotte Scheutz, Marius Corbu, Sebastian Iancu, Denisa Moaca, Alin Scarlat, Alexandru Tudor, Ioana Vizireanu, Andreea Calcan, Magdalena Ardelean, Sorin Ghemulet, Alexandru Pana, Aurel Constantinescu, Lucian Cusa, Alexandru Nica, Calin Baciu, Cristian Pop, Andrei Radovici, Alexandru Mereuta, Horatiu Stefanie, Bas Hermans, Stefan Schwietzke, Daniel Zavala-Araiza, Huilin Chen, and Thomas Röckmann more...
Abstract: Ambitious methane (CH4) emissions mitigation represents one of the most effective opportunities to slow the rate of global warming over the next decades. The oil and gas (O&G) sector is a significant source of methane emissions, with technically feasible and cost-effective emission mitigation options. Romania, a key O&G producer within the EU, with one of the highest reported annual CH4 emissions from the energy sector (Greenhouse Gas Inventory Data - Comparison by Category, 2022), can play an important role towards the EU’s emission reduction targets. In this study, we quantify CH4 emissions from onshore oil production sites in Romania at source and facility level using a combination of ground-based measurement techniques. Measured emissions were characterised by heavily skewed distributions, with 10 % of the sites accounting for more than 70 % of total emissions. Integrating the results from all site-level quantifications with different approaches, we derive a central estimate of 5.4 kg h–1 site-1 of CH4 (3.6–8.4, 95 % confidence interval) for oil production sites. This estimate represents one of the highest when compared to measurement-based estimates of similar facilities from other production regions. Based on our results, we estimate a total of 120 ktons CH4 yr–1 (range: 79–180 ktons yr–1) from oil wells in our studied areas in Romania. This is approximately 2.5 times higher than the total reported emissions from the Romanian oil production sector for 2020. Based on the source level characterization, up to three quarters of the detected emissions from oil production sites are related to operational venting. Our results suggest that O&G production infrastructure in Romania holds a massive mitigation potential, specifically by implementing measures to capture the gas and minimize operational venting and leaks. more...
Published: 2023
Full Text: View/download PDF

2. Supplementary material to 'High potential for CH4 emission mitigation from oil infrastructure in one of EU’s major production regions'

Author: Foteini Stavropoulou, Katarina Vinković, Bert Kers, Marcel de Vries, Steven van Heuven, Piotr Korbeń, Martina Schmidt, Julia Wietzel, Pawel Jagoda, Jaroslav M. Necki, Jakub Bartyzel, Hossein Maazallahi, Malika Menoud, Carina van der Veen, Sylvia Walter, Béla Tuzson, Jonas Ravelid, Randulph Paulo Morales, Lukas Emmenegger, Dominik Brunner, Michael Steiner, Arjan Hensen, Ilona Velzeboer, Pim van den Bulk, Hugo Denier van der Gon, Antonio Delre, Maklawe Essonanawe Edjabou, Charlotte Scheutz, Marius Corbu, Sebastian Iancu, Denisa Moaca, Alin Scarlat, Alexandru Tudor, Ioana Vizireanu, Andreea Calcan, Magdalena Ardelean, Sorin Ghemulet, Alexandru Pana, Aurel Constantinescu, Lucian Cusa, Alexandru Nica, Calin Baciu, Cristian Pop, Andrei Radovici, Alexandru Mereuta, Horatiu Stefanie, Bas Hermans, Stefan Schwietzke, Daniel Zavala-Araiza, Huilin Chen, and Thomas Röckmann more...
Published: 2023
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

3. Wind Tunnel Testing of a Common Research Model

Author: Stoica Corneliu, Mihaela Burghiu, Emanuel Trandafir, Eliza Apostol, Alexandru Nica, Alexandru Pana, Raluca Balasa, Dumitru Curt, Sorin Defta, Elena Vajaiac, and Catalin Pirvu
Published: 2023
Full Text: View/download PDF

4. A central limit theorem for star-generators of S∞, which relates to traceless CCR-GUE matrices

Author: Jacob Campbell, Claus Köstler, and Alexandru Nica
Subjects: General Mathematics
Abstract: We prove a limit theorem concerning the sequence of star-generators of [Formula: see text], where the expectation functional is provided by a character of [Formula: see text] with weights [Formula: see text] in the Thoma classification. The limit law turns out to be the law of a “traceless CCR-GUE” matrix, an analogue of the traceless GUE where the off-diagonal entries [Formula: see text] satisfy the commutation relation [Formula: see text]. The special case [Formula: see text] yields the law of a bona fide traceless GUE matrix, and we retrieve a result of Köstler and Nica from 2021, which in turn extended a result of Biane from 1995. more...
Published: 2022
Full Text: View/download PDF

5. A Central Limit Theorem for Star-Generators of $${S}_{\infty }$$, Which Relates to the Law of a GUE Matrix

Author: Claus Köstler and Alexandru Nica
Subjects: Statistics and Probability, General Mathematics, Star (game theory), 010102 general mathematics, Group algebra, 16. Peace & justice, Free probability, 01 natural sciences, Combinatorics, 010104 statistics & probability, Matrix (mathematics), Symmetric group, 0101 mathematics, Statistics, Probability and Uncertainty, Connection (algebraic framework), Random variable, Central limit theorem, Mathematics
Abstract: It is well known that, on a purely algebraic level, a simplified version of the central limit theorem (CLT) can be proved in the framework of a non-commutative probability space, under the hypotheses that the sequence of non-commutative random variables we consider is exchangeable and obeys a certain vanishing condition of some of its joint moments. In this approach (which covers versions for both the classical CLT and the CLT of free probability), the determination of the resulting limit law has to be addressed on a case-by-case basis. In this paper we discuss an instance of the above theorem that takes place in the framework of the group algebra $${{\mathbb {C}}}[ S_{\infty } ]$$ of the infinite symmetric group: The exchangeable sequence is provided by the star-generators of $$S_{\infty }$$ , and the expectation functional used on $${{\mathbb {C}}}[ S_{\infty } ]$$ depends in a natural way on a parameter $$d \in {{\mathbb {N}}}$$ . We identify precisely the limit distribution $$\mu _d$$ for this special instance of CLT, via a connection that $$\mu _d$$ turns out to have with the average empirical eigenvalue distribution of a random $$d \times d$$ GUE matrix. Moreover, we put into evidence a multivariate version of this result which follows from the observation that, on the level of calculations with pair-partitions, the (non-centered) star-generators are related to a (centered) exchangeable sequence of GUE matrices with independent entries. more...
Published: 2020
Full Text: View/download PDF

6. Using Boolean cumulants to study multiplication and anti-commutators of free random variables

Author: Maxime Fevrier, Kamil Szpojankowski, Mitja Mastnak, and Alexandru Nica
Subjects: Pure mathematics, 010201 computation theory & mathematics, Applied Mathematics, General Mathematics, 010102 general mathematics, Multiplication, 0102 computer and information sciences, 0101 mathematics, 01 natural sciences, Cumulant, Random variable, Mathematics
Abstract: We study how Boolean cumulants can be used in order to address operations with freely independent random variables, particularly in connection to the ∗ * -distribution of the product of two selfadjoint freely independent random variables, and in connection to the distribution of the anti-commutator of such random variables. A key instrument in our considerations is a new combinatorial object, coloured noncrossing partitions with a structural property which we call vertical no-repeat property. As a byproduct, we obtain several results concerning enumeration of some special sets of noncrossing partitions. more...
Published: 2020
Full Text: View/download PDF

7. The association of the Activities of Daily Living and the outcome of old intensive care patients suffering from COVID-19

Author: Bruno, Raphael Romano, Wernly, Bernhard, Flaatten, Hans, Fjølner, Jesper, Artigas, Antonio, Baldia, Philipp Heinrich, Binneboessel, Stephan, Bollen Pinto, Bernardo, Schefold, Joerg C., Wolff, Georg, Kelm, Malte, Beil, Michael, Sviri, Sigal, van Heerden, Peter Vernon, Szczeklik, Wojciech, Elhadi, Muhammed, Joannidis, Michael, Oeyen, Sandra, Kondili, Eumorfia, Marsh, Brian, Wollborn, Jakob, Andersen, Finn H., Moreno, Rui, Leaver, Susannah, Boumendil, Ariane, De Lange, Dylan W., Guidet, Bertrand, Jung, Christian, Eller, Philipp, Mesotten, Dieter, Reper, Pascal, Swinnen, Walter, Serck, Nicolas, Dewaele, Elisabeth, Brix, Helene, Brushoej, Jens, Kumar, Pritpal, Nedergaard, Helene Korvenius, Balleby, Ida Riise, Bundesen, Camilla, Hansen, Maria Aagaard, Uhrenholt, Stine, Bundgaard, Helle, Gooch, James, Cagova, Lenka, Potter, Elizabeth, Reay, Michael, Davey, Miriam, Abusayed, Mohammed Abdelshafy, Humphreys, Sally, Galbois, Arnaud, Charron, Cyril, Berlemont, Caroline Hauw, Besch, Guillaume, Rigaud, Jean-Philippe, Maizel, Julien, Djibré, Michel, Burtin, Philippe, Garcon, Pierre, Nseir, Saad, Valette, Xavier, Alexandru, Nica, Marin, Nathalie, Vaissiere, Marie, Plantefeve, Gaëtan, Vanderlinden, Thierry, Jurcisin, Igor, Megarbane, Buno, Chousterman, Benjamin Glenn, Dépret, François, Garnier, Marc, Besset, Sebastien, Oziel, Johanna, Ferre, Alexis, Dauger, Stéphane, Dumas, Guillaume, Goncalves, Bruno, Vettoretti, Lucie, Thevenin, Didier, Schaller, Stefan, Kurt, Muhammed, Faltlhauser, Andreas, Meyer, Christian, Milovanovic, Milena, Lutz, Matthias, Shala, Gonxhe, Haake, Hendrik, Randerath, Winfried, Kunstein, Anselm, Meybohm, Patrick, Steiner, Stephan, Barth, Eberhard, Poerner, Tudor, Simon, Philipp, Lorenz, Marco, Dindane, Zouhir, Kuhn, Karl Friedrich, Welte, Martin, Voigt, Ingo, Kabitz, Hans-Joachim, Goebel, Ulrich, Stoll, Sandra Emily, Kindgen-Milles, Detlef, Dubler, Simon, Fuest, Kristina, Schuster, Michael, Papadogoulas, Antonios, Mulita, Francesk, Rovina, Nikoletta, Aidoni, Zoi, Chrisanthopoulou, Evangelia, Andrianopoulos, Ioannis, Groenendijk, Martijn, Evers, Mirjam, van Lelyveld-Haas, Lenneke, Meynaar, Iwan, Cornet, Alexander Daniel, Zegers, Marieke, Dieperink, Willem, Dormans, Tom, Hahn, Michael, Sjøbøe, Britt, Strietzel, Hans Frank, Olasveengen, Theresa, Romundstad, Luis, Kluzik, Anna, Zatorski, Paweł, Drygalski, Tomasz, Klimkiewicz, Jakub, Solek-pastuszka, Joanna, Onichimowski, Dariusz, Czuczwar, Miroslaw, Gawda, Ryszard, Stefaniak, Jan, Stefanska-Wronka, Karina, Zabul, Ewa, Oliveira, Ana Isabel Pinho, Assis, Rui, de Lurdes Campos Santos, Maria, Santos, Henrique, Cardoso, Filipe Sousa, Gordinho, André, Banzo, Maria José Arche, Zalba-Etayo, Begoña, Cubero, Patricia Patricia, Priego, Jesús, Gomà, Gemma, Tomasa-Irriguible, Teresa Maria, Sancho, Susana, Ferreira, Aida Fernández, Vázquez, Eric Mayor, Mira, Ángela Prado, Ibarz, Mercedes, Iglesias, David, Arias-Rivera, Susana, Frutos-Vivar, Fernando, Lopez-Cuenca, Sonia, Aldecoa, Cesar, Perez-Torres, David, Canas-Perez, Isabel, Tamayo-Lomas, Luis, Diaz-Rodriguez, Cristina, de Gopegui, Pablo Ruiz, Ben-Hamouda, Nawfel, Roberti, Andrea, Fleury, Yvan, Abidi, Nour, Chau, Ivan, Dullenkopf, Alexander, Pugh, Richard, Smuts, Sara, COVIP study group, [missing], Critical care, Anesthesiology, Peri-operative and Emergency medicine (CAPE), NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM), COVIP study group, Eller, P., Joannidis, M., Mesotten, D., Reper, P., Oeyen, S., Swinnen, W., Serck, N., Dewaele, E., Brix, H., Brushoej, J., Kumar, P., Nedergaard, H.K., Balleby, I.R., Bundesen, C., Hansen, M.A., Uhrenholt, S., Bundgaard, H., Fjølner, J., Gooch, J., Cagova, L., Potter, E., Reay, M., Davey, M., Abusayed, M.A., Humphreys, S., Galbois, A., Guidet, B., Charron, C., Berlemont, C.H., Besch, G., Rigaud, J.P., Maizel, J., Djibré, M., Burtin, P., Garcon, P., Nseir, S., Valette, X., Alexandru, N., Marin, N., Vaissiere, M., Plantefeve, G., Vanderlinden, T., Jurcisin, I., Megarbane, B., Chousterman, B.G., Dépret, F., Garnier, M., Besset, S., Oziel, J., Ferre, A., Dauger, S., Dumas, G., Goncalves, B., Vettoretti, L., Thevenin, D., Schaller, S., Kurt, M., Faltlhauser, A., Meyer, C., Milovanovic, M., Lutz, M., Shala, G., Haake, H., Randerath, W., Kunstein, A., Meybohm, P., Steiner, S., Barth, E., Poerner, T., Simon, P., Lorenz, M., Dindane, Z., Kuhn, K.F., Welte, M., Voigt, I., Kabitz, H.J., Wollborn, J., Goebel, U., Stoll, S.E., Kindgen-Milles, D., Dubler, S., Jung, C., Fuest, K., Schuster, M., Papadogoulas, A., Mulita, F., Rovina, N., Aidoni, Z., Chrisanthopoulou, E., Kondili, E., Andrianopoulos, I., Groenendijk, M., Evers, M., van Lelyveld-Haas, L., Meynaar, I., Cornet, A.D., Zegers, M., Dieperink, W., De Lange, D.W., Dormans, T., Hahn, M., Sjøbøe, B., Strietzel, H.F., Olasveengen, T., Romundstad, L., Andersen, F.H., Kluzik, A., Zatorski, P., Drygalski, T., Szczeklik, W., Klimkiewicz, J., Solek-Pastuszka, J., Onichimowski, D., Czuczwar, M., Gawda, R., Stefaniak, J., Stefanska-Wronka, K., Zabul, E., Oliveira, AIP, Assis, R., de Lurdes Campos Santos, M., Santos, H., Cardoso, F.S., Gordinho, A., Banzo, MJA, Zalba-Etayo, B., Cubero, P.P., Priego, J., Gomà, G., Tomasa-Irriguible, T.M., Sancho, S., Ferreira, A.F., Vázquez, E.M., Mira, Á.P., Ibarz, M., Iglesias, D., Arias-Rivera, S., Frutos-Vivar, F., Lopez-Cuenca, S., Aldecoa, C., Perez-Torres, D., Canas-Perez, I., Tamayo-Lomas, L., Diaz-Rodriguez, C., de Gopegui, P.R., Ben-Hamouda, N., Roberti, A., Fleury, Y., Abidi, N., Schefold, J.C., Chau, I., Dullenkopf, A., Pugh, R., and Smuts, S. more...
Subjects: IMPACT, MORTALITY, ICU, Medicine and Health Sciences, ILL ELDERLY-PATIENTS, 610 Medicine & health, ddc:610, Critical Care and Intensive Care Medicine, 610 Medizin und Gesundheit, FRAILTY, human activities, Healthcare improvement science Radboud Institute for Health Sciences [Radboudumc 18]
Abstract: Open Access funding enabled and organized by Projekt DEAL. This study was endorsed by the ESICM. Free support for running the electronic database and was granted from the dep. of Epidemiology, University of Aarhus, Denmark. Bruno et al. Annals of Intensive Care (2022) 12:26 Page 10 of 11 The support of the study in France by a grant from Fondation Assistance Publique-Hôpitaux de Paris pour la recherche is greatly appreciated. In Norway, the study was supported by a grant from the Health Region West. In addition, the study was supported by a grant from the European Open Science Cloud (EOSC). EOSCsecretariat.eu has received funding from the European Union’s Horizon Programme call H2020-INFRAEOSC-05-2018-2019, grant agreement number 831644. This work was supported by the Collaborative Research Center SFB 1116 (German Research Foundation, DFG) and by the Forschungskommission of the Medical Faculty of the Heinrich-Heine-University Düsseldorf and No. 2020–21 to RRB for a Clinician Scientist Track. No (industry) sponsorship has been received for this investigator-initiated study. PURPOSE: Critically ill old intensive care unit (ICU) patients suffering from Sars-CoV-2 disease (COVID-19) are at increased risk for adverse outcomes. This post hoc analysis investigates the association of the Activities of Daily Living (ADL) with the outcome in this vulnerable patient group. METHODS: The COVIP study is a prospective international observational study that recruited ICU patients ≥ 70 years admitted with COVID-19 (NCT04321265). Several parameters including ADL (ADL; 0 = disability, 6 = no disability), Clinical Frailty Scale (CFS), SOFA score, intensive care treatment, ICU- and 3-month survival were recorded. A mixed-effects Weibull proportional hazard regression analyses for 3-month mortality adjusted for multiple confounders. RESULTS: This pre-specified analysis included 2359 patients with a documented ADL and CFS. Most patients evidenced independence in their daily living before hospital admission (80% with ADL = 6). Patients with no frailty and no disability showed the lowest, patients with frailty (CFS ≥ 5) and disability (ADL more...
Published: 2022
Full Text: View/download PDF

8. Characteristics and prognosis of bloodstream infection in patients with COVID-19 admitted in the ICU: an ancillary study of the COVID-ICU study

Author: Massart, Nicolas, Maxime, Virginie, Fillatre, Pierre, Razazi, Keyvan, Ferré, Alexis, Moine, Pierre, Legay, Francois, Voiriot, Guillaume, Amara, Marlene, Santi, Francesca, Nseir, Saad, Marque-Juillet, Stephanie, Bounab, Rania, Barbarot, Nicolas, Bruneel, Fabrice, Luyt, Charles-Edouard, Mercat, Alain, Asfar, Pierre, Beloncle, François, Demiselle, Julien, Pham, Tài, Pavot, Arthur, Monnet, Xavier, Richard, Christian, Demoule, Alexandre, Dres, Martin, Mayaux, Julien, Beurton, Alexandra, Daubin, Cédric, Descamps, Richard, Joret, Aurélie, Du Cheyron, Damien, Pene, Frédéric, Chiche, Jean-Daniel, Jozwiak, Mathieu, Jaubert, Paul, Fartoukh, Muriel, Teulier, Marion, Blayau, Clarisse, Bodenes, Laetitia, Ferriere, Nicolas, Auchabie, Johann, Le Meur, Anthony, Pignal, Sylvain, Mazzoni, Thierry, Quenot, Jean-Pierre, Andreu, Pascal, Roudau, Jean-Baptiste, Labruyère, Marie, Preau, Sébastien, Poissy, Julien, Mathieu, Daniel, Benhamida, Sarah, Paulet, Rémi, Roucaud, Nicolas, Thyrault, Martial, Daviet, Florence, Hraiech, Sami, Parzy, Gabriel, Sylvestre, Aude, Jochmans, Sébastien, Bouilland, Anne-Laure, Monchi, Mehran, Déserts, Marc Danguy Des, Mathais, Quentin, Rager, Gwendoline, Pasquier, Pierre, Reignier, Jean, Seguin, Amélie, Garret, Charlotte, Canet, Emmanuel, Dellamonica, Jean, Saccheri, Clément, Lombardi, Romain, Kouchit, Yanis, Jacquier, Sophie, Mathonnet, Armelle, Nay, Mai-Ahn, Runge, Isabelle, Martino, Frédéric, Flurin, Laure, Rolle, Amélie, Carles, Michel, Coudroy, Rémi, Thille, Arnaud, Frat, Jean-Pierre, Rodriguez, Maeva, Beuret, Pascal, Tientcheu, Audrey, Vincent, Arthur, Michelin, Florian, Tamion, Fabienne, Carpentier, Dorothée, Boyer, Déborah, Girault, Christophe, Gissot, Valérie, Ehrmann, Stéphan, Gandonniere, Charlotte Salmon, Elaroussi, Djlali, Delbove, Agathe, Fedun, Yannick, Huntzinger, Julien, Lebas, Eddy, Kisoka, Grâce, Grégoire, Céline, Marchetta, Stella, Lambermont, Bernard, Argaud, Laurent, Baudry, Thomas, Bertrand, Pierre-Jean, Dargent, Auguste, Guitton, Christophe, Chudeau, Nicolas, Landais, Mickaël, Darreau, Cédric, Ferre, Alexis, Gros, Antoine, Lacave, Guillaume, Neuville, Mathilde, Devaquet, Jérôme, Tachon, Guillaume, Gallo, Richard, Chelha, Riad, Galbois, Arnaud, Jallot, Anne, Lemoine, Ludivine Chalumeau, Kuteifan, Khaldoun, Pointurier, Valentin, Jandeaux, Louise-Marie, Mootien, Joy, Damoisel, Charles, Sztrymf, Benjamin, Schmidt, Matthieu, Combes, Alain, Chommeloux, Juliette, Luyt, Charles Edouard, Schortgen, Frédérique, Rusel, Leon, Jung, Camille, Gobert, Florent, Vimpere, Damien, Lamhaut, Lionel, Sauneuf, Bertrand, Charrrier, Liliane, Calus, Julien, Desmeules, Isabelle, Painvin, Benoît, Tadie, Jean-Marc, Castelain, Vincent, Michard, Baptiste, Herbrecht, Jean-Etienne, Baldacini, Mathieu, Weiss, Nicolas, Demeret, Sophie, Marois, Clémence, Rohaut, Benjamin, Moury, Pierre-Henri, Savida, Anne-Charlotte, Couadau, Emmanuel, Série, Mathieu, Alexandru, Nica, Bruel, Cédric, Fontaine, Candice, Garrigou, Sonia, Mahler, Juliette Courtiade, Leclerc, Maxime, Ramakers, Michel, Garçon, Pierre, Massou, Nicole, van Vong, Ly, Sen, Juliane, Lucas, Nolwenn, Chemouni, Franck, Stoclin, Annabelle, Avenel, Alexandre, Faure, Henri, Gentilhomme, Angélie, Ricome, Sylvie, Abraham, Paul, Monard, Céline, Textoris, Julien, Rimmele, Thomas, Montini, Florent, Lejour, Gabriel, Lazard, Thierry, Etienney, Isabelle, Kerroumi, Younes, Dupuis, Claire, Bereiziat, Marine, Coupez, Elisabeth, Thouy, François, Hoffmann, Clément, Donat, Nicolas, Chrisment, Anne, Blot, Rose-Marie, Kimmoun, Antoine, Jacquot, Audrey, Mattei, Matthieu, Levy, Bruno, Ravan, Ramin, Dopeux, Loïc, Liteaudon, Jean-Mathias, Roux, Delphine, Rey, Brice, Anghel, Radu, Schenesse, Deborah, Gevrey, Vincent, Castanera, Jermy, Petua, Philippe, Madeux, Benjamin, Hartman, Otto, Piagnerelli, Michael, Joosten, Anne, Noel, Cinderella, Biston, Patrick, Noel, Thibaut, Bouar, Gurvan, Boukhanza, Messabi, Demarest, Elsa, Bajolet, Marie-France, Charrier, Nathanaël, Quenet, Audrey, Zylberfajn, Cécile, Dufour, Nicolas, Mégarbane, Buno, Voicu, Sébastian, Deye, Nicolas, Malissin, Isabelle, Legay, François, Debarre, Matthieu, Delord, Bertrand, Laterrade, Thomas, Saghi, Tahar, Pujol, Wilfried, Cungi, Pierre Julien, Esnault, Pierre, Cardinale, Mickael, Ha, Vivien Hong Tuan, Fleury, Grégory, Brou, Marie-Ange, Zafimahazo, Daniel, Tran-Van, David, Avargues, Patrick, Carenco, Lisa, Robin, Nicolas, Ouali, Alexandre, Houdou, Lucie, Le Terrier, Christophe, Suh, Noémie, Primmaz, Steve, Pugin, Jérome, Weiss, Emmanuel, Gauss, Tobias, Moyer, Jean-Denis, Burtz, Catherine Paugam, La Combe, Béatrice, Smonig, Rolland, Violleau, Jade, Cailliez, Pauline, Chelly, Jonathan, Marchalot, Antoine, Saladin, Cécile, Bigot, Christelle, Fayolle, Pierre-Marie, Fatséas, Jules, Ibrahim, Amr, Resiere, Dabor, Hage, Rabih, Cholet, Clémentine, Cantier, Marie, Trouiler, Pierre, Montravers, Philippe, Lortat-Jacob, Brice, Tanaka, Sebastien, Dinh, Alexy Tran, Duranteau, Jacques, Harrois, Anatole, Dubreuil, Guillaume, Werner, Marie, Godier, Anne, Hamada, Sophie, Zlotnik, Diane, Nougue, Hélène, Mekontso-Dessap, Armand, Carteaux, Guillaume, de Prost, Nicolas, Mongardon, Nicolas, Lamraoui, Meriam, Alessandri, Claire, de Roux, Quentin, de Roquetaillade, Charles, Chousterman, Benjamin, Mebazaa, Alexandre, Gayat, Etienne, Garnier, Marc, Pardo, Emmanuel, Satre-Buisson, Lea, Gutton, Christophe, Yvin, Elise, Marcault, Clémence, Azoulay, Elie, Darmon, Michael, Oufella, Hafid Ait, Hariri, Geoffroy, Urbina, Tomas, Mazerand, Sandie, Heming, Nicholas, Annane, Djillali, Bouglé, Adrien, Omar, Edris, Lancelot, Aymeric, Begot, Emmanuelle, Plantefeve, Gaétan, Contou, Damien, Mentec, Hervé, Pajot, Olivier, Faguer, Stanislas, Cointault, Olivier, Lavayssiere, Laurence, Nogier, Marie-Béatrice, Jamme, Matthieu, Pichereau, Claire, Hayon, Jan, Outin, Hervé, Dépret, François, Coutrot, Maxime, Chaussard, Maité, Guillemet, Lucie, Goffin, Pierre, Thouny, Romain, Guntz, Julien, Jadot, Laurent, Persichini, Romain, Jean-Michel, Vanessa, Georges, Hugues, Caulier, Thomas, Pradel, Gaël, Hausermann, Marie-Hélène, Nguyen-Valat, Thi My Hue, Boudinaud, Michel, Vivier, Emmanuel, Rosseli, Sylvène, Bourdin, Gaël, Pommier, Christian, Vinclair, Marc, Poignant, Simon, Mons, Sandrine, Bougouin, Wulfran, Bruna, Franklin, Maestraggi, Quentin, Roth, Christian, Bitker, Laurent, Dhelft, François, Bonnet-Chateau, Justine, Filippelli, Mathilde, Morichau-Beauchant, Tristan, Thierry, Stéphane, Le Roy, Charlotte, Jouan, Mélanie Saint, Goncalves, Bruno, Mazeraud, Aurélien, Daniel, Matthieu, Sharshar, Tarek, Cadoz, Cyril, Gaci, Rostane, Gette, Sébastien, Louis, Guillaune, Sacleux, Sophe-Caroline, Ordan, Marie-Amélie, Cravoisy, Aurélie, Conrad, Marie, Courte, Guilhem, Gibot, Sébastien, Benzidi, Younès, Casella, Claudia, Serpin, Laurent, Setti, Jean-Lou, Besse, Marie-Catherine, Bourreau, Anna, Pillot, Jérôme, Rivera, Caroline, Vinclair, Camille, Robaux, Marie-Aline, Achino, Chloé, Delignette, Marie-Charlotte, Mazard, Tessa, Aubrun, Frédéric, Bouchet, Bruno, Frérou, Aurélien, Muller, Laura, Quentin, Charlotte, Degoul, Samuel, Stihle, Xavier, Sumian, Claude, Bergero, Nicoletta, Lanaspre, Bernard, Quintard, Hervé, Maiziere, Eve Marie, Egreteau, Pierre-Yves, Leloup, Guillaume, Berteau, Florin, Cottrel, Marjolaine, Bouteloup, Marie, Jeannot, Matthieu, Blanc, Quentin, Saison, Julien, Geneau, Isabelle, Grenot, Romaric, Ouchike, Abdel, Hazera, Pascal, Masse, Anne-Lyse, Demiri, Suela, Vezinet, Corinne, Baron, Elodie, Benchetrit, Deborah, Monsel, Antoine, Trebbia, Grégoire, Schaack, Emmanuelle, Lepecq, Raphaël, Bobet, Mathieu, Vinsonneau, Christophe, Dekeyser, Thibault, Delforge, Quentin, Rahmani, Imen, Vivet, Bérengère, Paillot, Jonathan, Hierle, Lucie, Chaignat, Claire, Valette, Sarah, Her, Benoït, Brunet, Jennifier, Page, Mathieu, Boiste, Fabienne, Collin, Anthony, Bavozet, Florent, Garin, Aude, Dlala, Mohamed, Mhamdi, Kais, Beilouny, Bassem, Lavalard, Alexandra, Perez, Severine, Veber, Benoit, Guitard, Pierre-Gildas, Gouin, Philippe, Lamacz, Anna, Plouvier, Fabienne, Delaborde, Bertrand, Kherchache, Aïssa, Chaalal, Amina, Ricard, Jean-Damien, Amouretti, Marc, Freita-Ramos, Santiago, Roux, Damien, Constantin, Jean-Michel, Assefi, Mona, Lecore, Marine, Selves, Agathe, Prevost, Florian, Lamer, Christian, Shi, Ruiying, Knani, Lyes, Floury, Sébastien Pili, Vettoretti, Lucie, Levy, Michael, Marsac, Lucile, Dauger, Stéphane, Guilmin-Crépon, Sophie, Winiszewski, Hadrien, Piton, Gael, Soumagne, Thibaud, Capellier, Gilles, Putegnat, Jean-Baptiste, Bayle, Frédérique, Perrou, Maya, Thao, Ghyslaine, Géri, Guillaume, Charron, Cyril, Repessé, Xavier, Vieillard-Baron, Antoine, Guilbart, Mathieu, Roger, Pierre-Alexandre, Hinard, Sébastien, Macq, Pierre-Yves, Chaulier, Kevin, Goutte, Sylvie, Chillet, Patrick, Pitta, Anaïs, Darjent, Barbara, Bruneau, Amandine, Lasocki, Sigismond, Leger, Maxime, Gergaud, Soizic, Lemarie, Pierre, Terzi, Nicolas, Schwebel, Carole, Dartevel, Anaïs, Galerneau, Louis-Marie, Diehl, Jean-Luc, Hauw-Berlemont, Caroline, Péron, Nicolas, Guérot, Emmanuel, Amoli, Abolfazl Mohebbi, Benhamou, Michel, Deyme, Jean-Pierre, Andremont, Olivier, Lena, Diane, Cady, Julien, Causeret, Arnaud, de la Chapelle, Arnaud, Cracco, Christophe, Rouleau, Stéphane, Schnell, David, Foucault, Camille, Lory, Cécile, Chapelle, Thibault, Bruckert, Vincent, Garcia, Julie, Sahraoui, Abdlazize, Abbosh, Nathalie, Bornstain, Caroline, Pernet, Pierre, Poirson, Florent, Pasem, Ahmed, Karoubi, Philippe, Poupinel, Virginie, Gauthier, Caroline, Bouniol, François, Feuchere, Philippe, Heron, Anne, Carreira, Serge, Emery, Malo, Le Floch, Anne Sophie, Giovannangeli, Luana, Herzog, Nicolas, Giacardi, Christophe, Baudic, Thibaut, Thill, Chloé, Lebbah, Said, Palmyre, Jessica, Tubach, Florence, Hajage, David, Bonnet, Nicolas, Ebstein, Nathan, Gaudry, Stéphane, Cohen, Yves, Noublanche, Julie, Lesieur, Olivier, Sément, Arnaud, Roca-Cerezo, Isabel, Pascal, Michel, Sma, Nesrine, Colin, Gwenhaël, Lacherade, Jean-Claude, Bionz, Gauthier, Maquigneau, Natacha, Bouzat, Pierre, Durand, Michel, Hérault, Marie-Christine, Payen, Jean-Francois, Centre hospitalier Saint-Brieuc, Hôpital Raymond Poincaré [Garches], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Hôpital Henri Mondor, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Henri Mondor-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Institut Mondor de Recherche Biomédicale (IMRB), Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR10-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Groupe de recherche clinique CARMAS (Cardiovascular and Respiratory Manifestations of Acute lung injury and Sepsis) (CARMAS), Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR10-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR10-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-CHU Henri Mondor [Créteil], Centre Hospitalier de Versailles André Mignot (CHV), CHU Lille, Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut de cardiologie [CHU Pitié-Salpêtrière], CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Institut de Cardiométabolisme et Nutrition = Institute of Cardiometabolism and Nutrition [CHU Pitié Salpêtrière] (IHU ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), INSERM UMRS-1144, Université Paris Cité, Réanimation Médicale et Toxicologique, Hôpital Lariboisière, COVID ICU Bacteremia Study Group on behalf of the COVID-ICU Investigators, CHU Tenon [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-CHU Henri Mondor, Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases [IHU ICAN], and Mégarbane, Bruno more...
Subjects: [SDV.MHEP.ME] Life Sciences [q-bio]/Human health and pathology/Emerging diseases, [SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases, RC86-88.9, Research, Correction, Medical emergencies. Critical care. Intensive care. First aid, bacterial infections and mycoses, Critical Care and Intensive Care Medicine, [SDV.MHEP.PSR]Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, [SDV.MHEP.CSC] Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, [SDV.TOX] Life Sciences [q-bio]/Toxicology, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.TOX]Life Sciences [q-bio]/Toxicology, [SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.MHEP.PSR] Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, human activities
Abstract: Background Patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-COV 2) and requiring intensive care unit (ICU) have a high incidence of hospital-acquired infections; however, data regarding hospital acquired bloodstream infections (BSI) are scarce. We aimed to investigate risk factors and outcome of BSI in critically ill coronavirus infectious disease-19 (COVID-19) patients. Patients and methods We performed an ancillary analysis of a multicenter prospective international cohort study (COVID-ICU study) that included 4010 COVID-19 ICU patients. For the present analysis, only those with data regarding primary outcome (death within 90 days from admission) or BSI status were included. Risk factors for BSI were analyzed using Fine and Gray competing risk model. Then, for outcome comparison, 537 BSI-patients were matched with 537 controls using propensity score matching. Results Among 4010 included patients, 780 (19.5%) acquired a total of 1066 BSI (10.3 BSI per 1000 patients days at risk) of whom 92% were acquired in the ICU. Higher SAPS II, male gender, longer time from hospital to ICU admission and antiviral drug before admission were independently associated with an increased risk of BSI, and interestingly, this risk decreased over time. BSI was independently associated with a shorter time to death in the overall population (adjusted hazard ratio (aHR) 1.28, 95% CI 1.05–1.56) and, in the propensity score matched data set, patients with BSI had a higher mortality rate (39% vs 33% p = 0.036). BSI accounted for 3.6% of the death of the overall population. Conclusion COVID-19 ICU patients have a high risk of BSI, especially early after ICU admission, risk that increases with severity but not with corticosteroids use. BSI is associated with an increased mortality rate. more...
Published: 2021
Full Text: View/download PDF

9. A construction which relates c-freeness to infinitesimal freeness

Author: Alexandru Nica, Maxime Fevrier, Kamil Szpojankowski, and Mitja Mastnak
Subjects: Multilinear map, Pure mathematics, Mathematics::Operator Algebras, Applied Mathematics, Infinitesimal, Probability (math.PR), 010102 general mathematics, Mathematics - Operator Algebras, Free probability, 01 natural sciences, Noncommutative geometry, Connection (mathematics), 010101 applied mathematics, Free product, FOS: Mathematics, Mathematics - Combinatorics, Combinatorics (math.CO), 0101 mathematics, Operator Algebras (math.OA), Random variable, Mathematics - Probability, Mathematics, Vector space
Abstract: We consider two extensions of free probability that have been studied in the research literature, and are based on the notions of c-freeness and respectively of infinitesimal freeness for noncommutative random variables. In a 2012 paper, Belinschi and Shlyakhtenko pointed out a connection between these two frameworks, at the level of their operations of 1-dimensional free additive convolution. Motivated by that, we propose a construction which produces a multi-variate version of the Belinschi-Shlyakhtenko result, together with a result concerning free products of multi-variate noncommutative distributions. Our arguments are based on the combinatorics of the specific types of cumulants used in c-free and in infinitesimal free probability. They work in a rather general setting, where the initial data consists of a vector space $V$ given together with a linear map $\Delta : V \to V \otimes V$. In this setting, all the needed brands of cumulants live in the guise of families of multilinear functionals on $V$, and our main result concerns a certain transformation $\Delta^{*}$ on such families of multilinear functionals., Comment: Version 2: Minor revision, added references more...
Published: 2019
Full Text: View/download PDF

10. Predicting 90-day survival of patients with COVID-19: Survival of Severely Ill COVID (SOSIC) scores

Author: Schmidt, Matthieu, Guidet, Bertrand, Demoule, Alexandre, Ponnaiah, Maharajah, Fartoukh, Muriel, Puybasset, Louis, Combes, Alain, Hajage, David, Mercat, Alain, Asfar, Pierre, Beloncle, François, Demiselle, Julien, Pham, Tài, Pavot, Arthur, Monnet, Xavier, Richard, Christian, Dres, Martin, Mayaux, Julien, Beurton, Alexandra, Daubin, Cédric, Descamps, Richard, Joret, Aurélie, Du Cheyron, Damien, Pene, Frédéric, Chiche, Jean-Daniel, Jozwiak, Mathieu, Jaubert, Paul, Voiriot, Guillaume, Teulier, Marion, Blayau, Clarisse, L’her, Erwen, Aubron, Cécile, Bodenes, Laetitia, Ferriere, Nicolas, Auchabie, Johann, Le Meur, Anthony, Pignal, Sylvain, Mazzoni, Thierry, Quenot, Jean-Pierre, Andreu, Pascal, Roudau, Jean-Baptiste, Labruyère, Marie, Nseir, Saad, Preau, Sébastien, Poissy, Julien, Mathieu, Daniel, Benhamida, Sarah, Paulet, Rémi, Roucaud, Nicolas, Thyrault, Martial, Daviet, Florence, Hraiech, Sami, Parzy, Gabriel, Sylvestre, Aude, Jochmans, Sébastien, Bouilland, Anne-Laure, Monchi, Mehran, Danguy Des Déserts, Marc, Mathais, Quentin, Rager, Gwendoline, Pasquier, Pierre, Jean, Reignier, Amélie, Seguin, Charlotte, Garret, Emmanuel, Canet, Dellamonica, Jean, Saccheri, Clément, Lombardi, Romain, Kouchit, Yanis, Jacquier, Sophie, Mathonnet, Armelle, Nay, Mai-Ahn, Runge, Isabelle, Martino, Frédéric, Flurin, Laure, Rolle, Amélie, Carles, Michel, Coudroy, Rémi, Thille, Arnaud, Frat, Jean-Pierre, Rodriguez, Maeva, Beuret, Pascal, Tientcheu, Audrey, Vincent, Arthur, Michelin, Florian, Tamion, Fabienne, Carpentier, Dorothée, Boyer, Déborah, Girault, Christophe, Gissot, Valérie, Ehrmann, Stéphan, Salmon Gandonniere, Charlotte, Elaroussi, Djlali, Delbove, Agathe, Fedun, Yannick, Huntzinger, Julien, Lebas, Eddy, Kisoka, Grâce, Grégoire, Céline, Marchetta, Stella, Lambermont, Bernard, Argaud, Laurent, Baudry, Thomas, Bertrand, Pierre-Jean, Dargent, Auguste, Guitton, Christophe, Chudeau, Nicolas, Landais, Mickaël, Darreau, Cédric, Ferre, Alexis, Gros, Antoine, Lacave, Guillaume, Bruneel, Fabrice, Neuville, Mathilde, Devaquet, Jérôme, Tachon, Guillaume, Gallot, Richard, Chelha, Riad, Galbois, Arnaud, Jallot, Anne, Chalumeau Lemoine, Ludivine, Kuteifan, Khaldoun, Pointurier, Valentin, Jandeaux, Louise-Marie, Mootien, Joy, Damoisel, Charles, Sztrymf, Benjamin, Chommeloux, Juliette, Luyt, Charles-Edouard, Schortgen, Frédérique, Rusel, Leon, Jung, Camille, Gobert, Florent, Vimpere, Damien, Lamhaut, Lionel, Sauneuf, Bertrand, Charrrier, Liliane, Calus, Julien, Desmeules, Isabelle, Painvin, Benoît, Tadie, Jean-Marc, Castelain, Vincent, Michard, Baptiste, Herbrecht, Jean-Etienne, Baldacini, Mathieu, Weiss, Nicolas, Demeret, Sophie, Marois, Clémence, Rohaut, Benjamin, Moury, Pierre-Henri, Savida, Anne-Charlotte, Couadau, Emmanuel, Série, Mathieu, Alexandru, Nica, Bruel, Cédric, Fontaine, Candice, Garrigou, Sonia, Courtiade Mahler, Juliette, Leclerc, Maxime, Ramakers, Michel, Garçon, Pierre, Massou, Nicole, van Vong, Ly, Sen, Juliane, Lucas, Nolwenn, Chemouni, Franck, Stoclin, Annabelle, Avenel, Alexandre, Faure, Henri, Gentilhomme, Angélie, Ricome, Sylvie, Abraham, Paul, Monard, Céline, Textoris, Julien, Rimmele, Thomas, Montini, Florent, Lejour, Gabriel, Lazard, Thierry, Etienney, Isabelle, Kerroumi, Younes, Dupuis, Claire, Bereiziat, Marine, Coupez, Elisabeth, Thouy, François, Hoffmann, Clément, Donat, Nicolas, Chrisment, Anne, Blot, Rose-Marie, Kimmoun, Antoine, Jacquot, Audrey, Mattei, Matthieu, Levy, Bruno, Ravan, Ramin, Dopeux, Loïc, Liteaudon, Jean-Mathias, Roux, Delphine, Rey, Brice, Anghel, Radu, Schenesse, Deborah, Gevrey, Vincent, Castanera, Jermy, Petua, Philippe, Madeux, Benjamin, Hartman, Otto, Piagnerelli, Michael, Joosten, Anne, Noel, Cinderella, Biston, Patrick, Noel, Thibaut, Bouar, Gurvan, Boukhanza, Messabi, Demarest, Elsa, Bajolet, Marie-France, Charrier, Nathanaël, Quenet, Audrey, Zylberfajn, Cécile, Dufour, Nicolas, Mégarbane, Buno, Voicu, Sqébastian, Deye, Nicolas, Malissin, Isabelle, Legay, François, Debarre, Matthieu, Barbarot, Nicolas, Fillatre, Pierre, Delord, Bertrand, Laterrade, Thomas, Saghi, Tahar, Pujol, Wilfried, Cungi, Pierre-Julien, Esnault, Pierre, Cardinale, Mickael, Hong Tuan Ha, Vivien, Fleury, Grégory, Brou, Marie-Ange, Zafimahazo, Daniel, Tran-Van, David, Avargues, Patrick, Carenco, Lisa, Robin, Nicolas, Ouali, Alexandre, Houdou, Lucie, Le Terrier, Christophe, Suh, Noémie, Primmaz, Steve, Pugin, Jérome, Weiss, Emmanuel, Gauss, Tobias, Moyer, Jean-Denis, Paugam Burtz, Catherine, La Combe, Béatrice, Smonig, Rolland, Violleau, Jade, Cailliez, Pauline, Chelly, Jonathan, Marchalot, Antoine, Saladin, Cécile, Bigot, Christelle, Fayolle, Pierre-Marie, Fatséas, Jules, Ibrahim, Amr, Resiere, Dabor, Hage, Rabih, Cholet, Clémentine, Cantier, Marie, Trouiler, Pierre, Montravers, Philippe, Lortat-Jacob, Brice, Tanaka, Sebastien, Tran Dinh, Alexy, Duranteau, Jacques, Harrois, Anatole, Dubreuil, Guillaume, Werner, Marie, Godier, Anne, Hamada, Sophie, Zlotnik, Diane, Nougue, Hélène, Mekontso-Dessap, Armand, Carteaux, Guillaume, Razazi, Keyvan, de Prost, Nicolas, Mongardon, Nicolas, Langeron, Olivier, Levesque, Eric, Attias, Arié, de Roquetaillade, Charles, Chousterman, Benjamin, Mebazaa, Alexandre, Gayat, Etienne, Garnier, Marc, Pardo, Emmanuel, Satre-Buisson, Lea, Gutton, Christophe, Yvin, Elise, Marcault, Clémence, Azoulay, Elie, Darmon, Michael, Ait Oufella, Hafid, Hariri, Geoffroy, Urbina, Tomas, Mazerand, Sandie, Heming, Nicholas, Santi, Francesca, Moine, Pierre, Annane, Djillali, Bouglé, Adrien, Omar, Edris, Lancelot, Aymeric, Begot, Emmanuelle, Plantefeve, Gaétan, Contou, Damien, Mentec, Hervé, Pajot, Olivier, Faguer, Stanislas, Cointault, Olivier, Lavayssiere, Laurence, Nogier, Marie-Béatrice, Jamme, Matthieu, Pichereau, Claire, Hayon, Jan, Outin, Hervé, Dépret, François, Coutrot, Maxime, Chaussard, Maité, Guillemet, Lucie, Goffin, Pierre, Thouny, Romain, Guntz, Julien, Jadot, Laurent, Persichini, Romain, Jean-Michel, Vanessa, Georges, Hugues, Caulier, Thomas, Pradel, Gaël, Hausermann, Marie-Hélène, Nguyen-Valat, Thi My Hue, Boudinaud, Michel, Vivier, Emmanuel, Rosseli, Sylvène, Bourdin, Gaël, Pommier, Christian, Vinclair, Marc, Poignant, Simon, Mons, Sandrine, Bougouin, Wulfran, Bruna, Franklin, Maestraggi, Quentin, Roth, Christian, Bitker, Laurent, Dhelft, François, Bonnet-Chateau, Justine, Filippelli, Mathilde, Morichau-Beauchant, Tristan, Thierry, Stéphane, Le Roy, Charlotte, Saint Jouan, Mélanie, Goncalves, Bruno, Mazeraud, Aurélien, Daniel, Matthieu, Sharshar, Tarek, Cadoz, Cyril, Gaci, Rostane, Gette, Sébastien, Louis, Guillaune, Sacleux, Sophe-Caroline, Ordan, Marie-Amélie, Cravoisy, Aurélie, Conrad, Marie, Courte, Guilhem, Gibot, Sébastien, Benzidi, Younès, Casella, Claudia, Serpin, Laurent, Setti, Jean-Lou, Besse, Marie-Catherine, Bourreau, Anna, Pillot, Jérôme, Rivera, Caroline, Vinclair, Camille, Robaux, Marie-Aline, Achino, Chloé, Delignette, Marie-Charlotte, Mazard, Tessa, Aubrun, Frédéric, Bouchet, Bruno, Frérou, Aurélien, Muller, Laura, Quentin, Charlotte, Degoul, Samuel, Stihle, Xavier, Sumian, Claude, Bergero, Nicoletta, Lanaspre, Bernard, Quintard, Hervé, Maiziere, Eve Marie, Egreteau, Pierre-Yves, Leloup, Guillaume, Berteau, Florin, Cottrel, Marjolaine, Bouteloup, Marie, Jeannot, Matthieu, Blanc, Quentin, Saison, Julien, Geneau, Isabelle, Grenot, Romaric, Ouchike, Abdel, Hazera, Pascal, Masse, Anne-Lyse, Demiri, Suela, Vezinet, Corinne, Baron, Elodie, Benchetrit, Deborah, Monsel, Antoine, Trebbia, Grégoire, Schaack, Emmanuelle, Lepecq, Raphaël, Bobet, Mathieu, Vinsonneau, Christophe, Dekeyser, Thibault, Delforge, Quentin, Rahmani, Imen, Vivet, Bérengère, Paillot, Jonathan, Hierle, Lucie, Chaignat, Claire, Valette, Sarah, Her, Benoït, Brunet, Jennifier, Page, Mathieu, Boiste, Fabienne, Collin, Anthony, Bavozet, Florent, Garin, Aude, Dlala, Mohamed, Mhamdi, Kais, Beilouny, Bassem, Lavalard, Alexandra, Perez, Severine, Veber, Benoit, Guitard, Pierre-Gildas, Gouin, Philippe, Lamacz, Anna, Plouvier, Fabienne, Delaborde, Bertrand, Kherchache, Aïssa, Chaalal, Amina, Ricard, Jean-Damien, Amouretti, Marc, Freita-Ramos, Santiago, Roux, Damien, Constantin, Jean-Michel, Assefi, Mona, Lecore, Marine, Selves, Agathe, Prevost, Florian, Lamer, Christian, Shi, Ruiying, Knani, Lyes, Pili Floury, Sébastien, Vettoretti, Lucie, Levy, Michael, Marsac, Lucile, Dauger, Stéphane, Guilmin-Crépon, Sophie, Winiszewski, Hadrien, Piton, Gael, Soumagne, Thibaud, Capellier, Gilles, Putegnat, Jean-Baptiste, Bayle, Frédérique, Perrou, Maya, Thao, Ghyslaine, Géri, Guillaume, Charron, Cyril, Repessé, Xavier, Vieillard-Baron, Antoine, Guilbart, Mathieu, Roger, Pierre-Alexandre, Hinard, Sébastien, Macq, Pierre-Yves, Chaulier, Kevin, Goutte, Sylvie, Chillet, Patrick, Pitta, Anaïs, Darjent, Barbara, Bruneau, Amandine, Lasocki, Sigismond, Leger, Maxime, Gergaud, Soizic, Lemarie, Pierre, Terzi, Nicolas, Schwebel, Carole, Dartevel, Anaïs, Galerneau, Louis-Marie, Diehl, Jean-Luc, Hauw-Berlemont, Caroline, Péron, Nicolas, Guérot, Emmanuel, Mohebbi Amoli, Abolfazl, Benhamou, Michel, Deyme, Jean-Pierre, Andremont, Olivier, Lena, Diane, Cady, Julien, Causeret, Arnaud, de la Chapelle, Arnaud, Cracco, Christophe, Rouleau, Stéphane, Schnell, David, Foucault, Camille, Lory, Cécile, Chapelle, Thibault, Bruckert, Vincent, Garcia, Julie, Sahraoui, Abdlazize, Abbosh, Nathalie, Bornstain, Caroline, Pernet, Pierre, Poirson, Florent, Pasem, Ahmed, Karoubi, Philippe, Poupinel, Virginie, Gauthier, Caroline, Bouniol, François, Feuchere, Philippe, Heron, Anne, Carreira, Serge, Emery, Malo, Le Floch, Anne Sophie, Giovannangeli, Luana, Herzog, Nicolas, Giacardi, Christophe, Baudic, Thibaut, Thill, Chloé, Lebbah, Said, Palmyre, Jessica, Tubach, Florence, Bonnet, Nicolas, Ebstein, Nathan, Gaudry, Stéphane, Cohen, Yves, Noublanche, Julie, Lesieur, Olivier, Sément, Arnaud, Roca-Cerezo, Isabel, Pascal, Michel, Sma, Nesrine, Colin, Gwenhaël, Lacherade, Jean-Claude, Bionz, Gauthier, Maquigneau, Natacha, Bouzat, Pierre, Durand, Michel, Hérault, Marie-Christine, Payen, Jean-Francois, Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Institut de Cardiométabolisme et Nutrition = Institute of Cardiometabolism and Nutrition [CHU Pitié Salpêtrière] (IHU ICAN), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), REanimation et Soins intensifs du Patient en Insuffisance Respiratoire aigüE [CHU Pitié-Salpêtrière] (GRC RESPIRE), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Institut Pierre Louis d'Epidémiologie et de Santé Publique (iPLESP), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Neurophysiologie Respiratoire Expérimentale et Clinique (UMRS 1158), Département Médico-Universitaire APPROCHES, CHU Tenon [AP-HP], Groupe de recherche clinique CARMAS (Cardiovascular and Respiratory Manifestations of Acute lung injury and Sepsis) (CARMAS), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-CHU Henri Mondor, Laboratoire d'Imagerie Biomédicale (LIB), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Pharmacoépidémiologie de l'AP-HP (Cephepi), INSERM UMRS-1144, Université Paris Cité, Réanimation Médicale et Toxicologique, Hôpital Lariboisière, and Mégarbane, Bruno more...
Subjects: [SDV.MHEP.ME] Life Sciences [q-bio]/Human health and pathology/Emerging diseases, [SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases, Acute respiratory distress syndrome, RC86-88.9, Research, COVID-19, Medical emergencies. Critical care. Intensive care. First aid, Critical Care and Intensive Care Medicine, Predictive survival model, [SDV.MHEP.PSR]Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, [SDV.MHEP.CSC] Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, [SDV.TOX] Life Sciences [q-bio]/Toxicology, Mechanical ventilation, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.TOX]Life Sciences [q-bio]/Toxicology, [SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.MHEP.PSR] Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, Outcome
Abstract: Background Predicting outcomes of critically ill intensive care unit (ICU) patients with coronavirus-19 disease (COVID-19) is a major challenge to avoid futile, and prolonged ICU stays. Methods The objective was to develop predictive survival models for patients with COVID-19 after 1-to-2 weeks in ICU. Based on the COVID–ICU cohort, which prospectively collected characteristics, management, and outcomes of critically ill patients with COVID-19. Machine learning was used to develop dynamic, clinically useful models able to predict 90-day mortality using ICU data collected on day (D) 1, D7 or D14. Results Survival of Severely Ill COVID (SOSIC)-1, SOSIC-7, and SOSIC-14 scores were constructed with 4244, 2877, and 1349 patients, respectively, randomly assigned to development or test datasets. The three models selected 15 ICU-entry variables recorded on D1, D7, or D14. Cardiovascular, renal, and pulmonary functions on prediction D7 or D14 were among the most heavily weighted inputs for both models. For the test dataset, SOSIC-7’s area under the ROC curve was slightly higher (0.80 [0.74–0.86]) than those for SOSIC-1 (0.76 [0.71–0.81]) and SOSIC-14 (0.76 [0.68–0.83]). Similarly, SOSIC-1 and SOSIC-7 had excellent calibration curves, with similar Brier scores for the three models. Conclusion The SOSIC scores showed that entering 15 to 27 baseline and dynamic clinical parameters into an automatable XGBoost algorithm can potentially accurately predict the likely 90-day mortality post-ICU admission (sosic.shinyapps.io/shiny). Although external SOSIC-score validation is still needed, it is an additional tool to strengthen decisions about life-sustaining treatments and informing family members of likely prognosis. more...
Published: 2021
Full Text: View/download PDF

11. Multiplicative and semi-multiplicative functions on non-crossing partitions, and relations to cumulants

Author: Adrian Celestino, Kurusch Ebrahimi-Fard, Alexandru Nica, Daniel Perales, and Leon Witzman
Subjects: Applied Mathematics, Probability (math.PR), Mathematics - Operator Algebras, FOS: Mathematics, Mathematics - Combinatorics, Combinatorics (math.CO), Operator Algebras (math.OA), Mathematics - Probability
Abstract: We consider the group $(\mathcal{G},*)$ of unitized multiplicative functions in the incidence algebra of non-crossing partitions, where ``$*$'' denotes the convolution operation. We introduce a larger group $(\widetilde{\mathcal{G}},*)$ of unitized functions from the same incidence algebra, which satisfy a weaker condition of being ``semi-multiplicative''. The natural action of $\widetilde{\mathcal{G}}$ on sequences of multilinear functionals of a non-commutative probability space captures the combinatorics of transitions between moments and some brands of cumulants that are studied in the non-commutative probability literature. We use the framework of $\widetilde{\mathcal{G}}$ in order to explain why the multiplication of free random variables can be very nicely described in terms of Boolean cumulants and more generally in terms of $t$-Boolean cumulants, a one-parameter interpolation between free and Boolean cumulants arising from work of Bozejko and Wysoczanski. It is known that the group $\mathcal{G}$ can be naturally identified as the group of characters of the Hopf algebra Sym of symmetric functions. We show that $\widetilde{\mathcal{G}}$ can also be identified as group of characters of a Hopf algebra $\mathcal{T}$, which is an incidence Hopf algebra in the sense of Schmitt. Moreover, the inclusion of $\mathcal{G}$ into $\widetilde{\mathcal{G}}$ turns out to be the dual of a natural bialgebra homomorphism from $\mathcal{T}$ onto Sym., Comment: Version 2: Small corrections and some added material in Sections 11 and 12 more...
Published: 2021
Full Text: View/download PDF

12. Lactate is associated with mortality in very old intensive care patients suffering from COVID-19: results from an international observational study of 2860 patients

Author: Bruno, Raphael Romano, Wernly, Bernhard, Flaatten, Hans, Artigas, Antonio, Bollen Pinto, Bernardo, Binnebössel, Stephan, Baldia, Philipp Heinrich, Kelm, Malte, Beil, Michael, Sigal, Sivri, van Heerden, Peter Vernon, Elhadi, Muhammed, Zafeiridis, Tilemachos, Arche Banzo, Maria José, Moreno, Rui, Boumendil, Ariane, De Lange, Dylan W., Eller, Philipp, Joannidis, Michael, Mesotten, Dieter, Reper, Pascal, Oeyen, Sandra, Swinnen, Walter, Serck, Nicolas, Dewaele, Elisabeth, Chapeta, Edwin, Brix, Helene, Brushoej, Jens, Kumar, Pritpal, Nedergaard, Helene Korvenius, Johnsen, Tim Koch, Bundesen, Camilla, Hansen, Maria Aagaard, Uhrenholt, Stine, Bundgaard, Helle, Fjølner, Jesper, Innes, Richard, Gooch, James, Cagova, Lenka, Potter, Elizabeth, Reay, Michael, Davey, Miriam, Abusayed, Mohammed Abdelshafy, Humphreys, Sally, Collins, Amy, Aujayeb, Avinash, Leaver, Susannah, Khaliq, Waqas, Habib, Ayman Abdelmawgoad, Azab, Mohammed A., Wassim, Kyrillos, Elgazzar, Yumna A., Salah, Rehab, Abosheaishaa, Hazem Maarouf, Hussein Mohamed, Aliae A. R., Azzam, Ahmed Y., Tharwat, Samar, Ali, Yasmin Khairy Nasreldin Mohamed, Elmandouh, Omar, Galal, Islam, Abu-Elfatth, Ahmed, Motawea, Karam, Elbahnasawy, Mohammad, Shehata, Mostafa, Elbahnasawy, Mohamed, Tayeb, Mostafa, Osman, Nermin, Abdel-Elsalam, Wafaa, Hussein, Aliae Mohamed, Aldhalia, Amer, Galbois, Arnaud, Guidet, Bertrand, Charron, Cyril, Berlemont, Caroline Hauw, Besch, Guillaume, Rigaud, Jean-Philippe, Maizel, Julien, Djibré, Michel, Burtin, Philippe, Garcon, Pierre, Nseir, Saad, Valette, Xavier, Alexandru, Nica, Marin, Nathalie, Vaissiere, Marie, Plantefeve, Gaëtan, Mentec, Hervé, Vanderlinden, Thierry, Jurcisin, Igor, Megarbane, Buno, Chousterman, Benjamin Glenn, Dépret, François, Garnier, Marc, Besset, Sebastien, Oziel, Johanna, Ferre, Alexis, Dauger, Stéphane, Dumas, Guillaume, Goncalves, Bruno, Vettoretti, Lucie, Thevenin, Didier, Schaller, Stefan, Kurt, Muhammed, Faltlhauser, Andreas, Meyer, Christian, Milovanovic, Milena, Lutz, Matthias, Shala, Gonxhe, Haake, Hendrik, Randerath, Winfried, Kunstein, Anselm, Meybohm, Patrick, Barth, Eberhard, Poerner, Tudor, Simon, Philipp, Lorenz, Marco, Dindane, Zouhir, Kuhn, Karl Friedrich, Welte, Martin, Voigt, Ingo, Kabitz, Hans-Joachim, Wollborn, Jakob, Goebel, Ulrich, Stoll, Sandra Emily, Kindgen-Milles, Detlef, Dubler, Simon, Jung, Christian, Fuest, Kristina, Schuster, Michael, Steiner, Stephan, Papadogoulas, Antonios, Mulita, Francesk, Rovina, Nikoletta, Aidoni, Zoi, Chrisanthopoulou, Evangelia, Kondili, Eumorfia, Andrianopoulos, Ioannis, Gurjar, Mohan, Mahmoodpoor, Ata, Hussein, Rand, Al-Juaifari, Maytham Aqeel, Karantenachy, Abdullah Khudhur Ahmed, Sviri, Sigal, Elsaka, Ahmed, Marsh, Brian, Comellini, Vittoria, Al-Ali, Farah, Almani, Sari, Khamees, Almu' Atasim, Al-Shami, Khayry, El Din, Ibrahim Salah, Abubaker, Taha, Ahmed, Hazem, Rabha, Ahmed, Emhamed, Marwa, Abdeewi, Saedah, Abusalama, Abdurraouf, Alhadi, Abdulmueti, Huwaysh, Mohammed, Alghati, Esraa Abdalqader, Ghannam, Abdelilah, Namendys-Sylva, Silvio A., Groenendijk, Martijn, Evers, Mirjam, Van Lelyveld-Haas, Lenneke, Meynaar, Iwan, Cornet, Alexander Daniel, Zegers, Marieke, Dieperink, Willem, De Lange, Dylan, Dormans, Tom, Hahn, Michael, Sjøbøe, Britt, Strietzel, Hans Frank, Olasveengen, Theresa, Romundstad, Luis, Andersen, Finn H., Massoud, John George Grace, Khan, Aamir Ghafoor, Al-Qasrawi, Shahd, Amro, Sarah, Kluzik, Anna, Zatorski, Pawel, Drygalski, Tomasz, Szczeklik, Wojciech, Klimkiewicz, Jakub, Solek-Pastuszka, Joanna, Onichimowski, Dariusz, Czuczwar, Miroslaw, Gawda, Ryszard, Stefaniak, Jan, Stefanska-Wronka, Karina, Zabul, Ewa, Oliveira, Ana Isabel Pinho, Assis, Rui, De Lurdes Campos Santos, Maria, Santos, Henrique, Cardoso, Filipe Sousa, Gordinho, André, Grintescu, Ioana Marina, Tomescu, Dana, Badawy, Mohamed Raafat, José Arche Banzo, M., Zalba-Etayo, Begoña, Cubero, Patricia Jimeno, Priego, Jesús, Gomà, Gemma, Tomasa-Irriguible, Teresa Maria, Sancho, Susana, Ferreira, Aida Fernández, Vázquez, Eric Mayor, Mira, Ángela Prado, Ibarz, Mercedes, Iglesias, David, Arias-Rivera, Susana, Frutos-Vivar, Fernando, Lopez-Cuenca, Sonia, Aldecoa, Cesar, Perez-Torres, David, Canas-Perez, Isabel, Tamayo-Lomas, Luis, Diaz-Rodriguez, Cristina, De Gopegui, Pablo Ruiz, Saleh, Mahmoud, Hilles, Momin Majed Yousuf, Abualqumboz, Enas M. Y., Ben-Hamouda, Nawfel, Roberti, Andrea, Fleury, Yvan, Abidi, Nour, Schefold, Joerg C., Chau, Ivan, Dullenkopf, Alexander, Chaaban, Mohammad Karam, Shebani, Mohammed Mouaz, Hmaideh, Ahmad, Shaher, Aymen, Sahin, Ayca Sultan, Saracoglu, Kemal Tolga, Al-Sadawi, Mohammed, Pugh, Richard, Smuts, Sara, and Al-Saban, Rafat Ameen Mohammed more...
Subjects: Research, Intensive / Critical Care Medicine, Emergency Medicine, Anesthesiology, ddc
Published: 2020

13. A Tunable 3rd – OrderLow–PassFilter for ECG Acquisition Using Capacitance Multiplier

Author: Viorel-Stefan Savinescu, Ioan-Alexandru Nica, and Liviu Goras
Published: 2020
Full Text: View/download PDF

14. Algorithm and Model for a Fixed Sun Position Detection System

Author: Stefan Viorel Savinescu, Ioan Alexandru Nica, Gabriel Bonteanu, Arcadie Cracan, and Radu Gabriel Bozomitu
Subjects: Sunlight, Physics, Brightness, Optical fiber, business.industry, Photoelectric sensor, Position of the Sun, Physics::Optics, Image processing, Grayscale, law.invention, Optics, law, Position (vector), business
Abstract: A sun position detection system that is not based on movements made by mechanical components is presented. The proposed solution uses a low-resolution optical sensor as a detection element and a number of optical fibers placed with one end on the surface of a hemisphere and the other in the proximity of the photo sensor serving as solar light guides. The structural arrangement of the fibers maps points on the surface of the sensor hemisphere to points on the optical sensor. Having a well-established correlation between the insertion position of each of the optical fibers on the surface of the dome exposed to sunlight and the area of the photo sensor that each of the optical fibers illuminates, it is possible to determine the position of the Sun on the celestial vault by processing the photo sensor output (by identifying the maximum brightness spots in the resulting grayscale image). more...
Published: 2019
Full Text: View/download PDF

15. True Random Number Generator Using an Active Inductor Based Oscillator

Author: Ioan-Alexandru Nica, Liviu Goras, and Viorel-Stefan Savinescu
Subjects: 010302 applied physics, Physics, Random number generation, 020208 electrical & electronic engineering, 02 engineering and technology, Topology, Inductor, 01 natural sciences, Power budget, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Entropy (information theory), Field-programmable gate array, Electronic circuit, Jitter
Abstract: Oscillator jitter is commonly used as a source of entropy in true random number generators (TRNG). Circuits based on this phenomenon are usually built with ring oscillators (ROs) mostly because of their simplicity and ease of testing (on a FPGA). In this paper we investigate the use of active inductor based oscillators (AI-OSC) in TRNG. Two designs are compared, in a $0.18\mu\mathrm{m}$ technology provided by AMS, one with ROs and one with AI-OSC. It is shown that the latter has better statistical proprieties for the same power budget ( $450\mu\mathrm{W}$ ) and speed (40 Mbps). more...
Published: 2019
Full Text: View/download PDF

16. Free Random Variables

Author: Dan Voiculescu, Kenneth J. Dykema, Alexandru Nica, Dan Voiculescu, Kenneth J. Dykema, and Alexandru Nica
Abstract: This book presents the first comprehensive introduction to free probability theory, a highly noncommutative probability theory with independence based on free products instead of tensor products. Basic examples of this kind of theory are provided by convolution operators on free groups and by the asymptotic behavior of large Gaussian random matrices. The probabilistic approach to free products has led to a recent surge of new results on the von Neumann algebras of free groups. The book is ideally suited as a textbook for an advanced graduate course and could also provide material for a seminar. In addition to researchers and graduate students in mathematics, this book will be of interest to physicists and others who use random matrices. more...
Published: 2017

17. Investigating automatic vectorization for real-time 3D scene understanding

Author: Paul H. J. Kelly, Alexandru Nica, Pablo Gonzélez de Aledo, and Emanuele Vespa
Subjects: Exploit, business.industry, Computer science, 020207 software engineering, 010103 numerical & computational mathematics, 02 engineering and technology, Observer (special relativity), Simultaneous localization and mapping, 01 natural sciences, Support vector machine, 0202 electrical engineering, electronic engineering, information engineering, Computer vision, Artificial intelligence, Central processing unit, 0101 mathematics, Geometric space, business
Abstract: Simultaneous Localization And Mapping (SLAM) is the problem of building a representation of a geometric space while simultaneously estimating the observer's location within the space. While this seems to be a chicken-and-egg problem, several algorithms have appeared in the last decades that approximately and iteratively solve this problem. SLAM algorithms are tailored to the available resources, hence aimed at balancing the precision of the map with the constraints that the computational platform imposes and the desire to obtain real-time results. Working with KinectFusion, an established SLAM implementation, we explore in this work the vectorization opportunities present in this scenario, with the goal of using the CPU to its full potential. Using ISPC, an automatic vectorization tool, we produce a partially vectorized version of KinectFusion. Along the way we explore a number of optimization strategies, among which tiling to exploit ray-coherence and outer loop vectorization, obtaining up to 4x speed-up over the baseline on an 8-wide vector machine. more...
Published: 2018
Full Text: View/download PDF

18. On the modeling of an active resonator

Author: Liviu Goras, Viorel-Stefan Savinescu, and Ioan-Alexandru Nica
Subjects: Engineering, business.industry, 020208 electrical & electronic engineering, Transistor, 020206 networking & telecommunications, Biasing, 02 engineering and technology, Inductor, law.invention, Resonator, law, Q factor, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, RLC circuit, Parasitic extraction, Cascode, business
Abstract: In this paper an improved small-signal model of an active inductor taking into consideration active and biasing transistors parasitics is presented. It is shown that the effect of the biasing resistance of the cascode transistor increases to three the order of the system. The influence of the parasitic elements on stability and a noise analysis of the circuit are studied as well. more...
Published: 2017
Full Text: View/download PDF

19. On the non-ideal behavior of a cross-coupled CMOS transistor Negative Impedance Circuit

Author: Ioan-Alexandru Nica, Liviu Goras, and Viorel-Stefan Savinescu
Subjects: 010302 applied physics, Engineering, Ideal (set theory), business.industry, 020208 electrical & electronic engineering, Hardware_PERFORMANCEANDRELIABILITY, 02 engineering and technology, Filter capacitor, 01 natural sciences, Capacitance, law.invention, Cross coupled, Capacitor, CMOS, Hardware_GENERAL, law, 0103 physical sciences, MOSFET, Hardware_INTEGRATEDCIRCUITS, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, business, Electrical impedance
Abstract: A detailed analysis of the nonideal behavior of a cross-coupled CMOS transistor pair used to implement negative resistances and capacitors is presented. Improvement solutions are given as well.
Published: 2017
Full Text: View/download PDF

20. Convolution powers in the operator-valued framework

Author: Michael Anshelevich, Maxime Fevrier, Alexandru Nica, Serban T. Belinschi, Department of Mathematics [Texas A&M University], Texas A&M University [College Station], Department of Mathematics & Statistics, Queen's University, Institute of Mathematics 'Simion Stoilow', Romanian Academy of Sciences, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Department of Pure Mathematics [Waterloo], University of Waterloo [Waterloo], Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS) more...
Subjects: Pure mathematics, General Mathematics, Convolution power, 01 natural sciences, Convolution, 010104 statistics & probability, FOS: Mathematics, [MATH]Mathematics [math], 0101 mathematics, Connection (algebraic framework), Operator Algebras (math.OA), ComputingMilieux_MISCELLANEOUS, Mathematics, 46L53 (46L54), 46L54, Semigroup, Applied Mathematics, Probability (math.PR), 010102 general mathematics, Mathematics - Operator Algebras, 16. Peace & justice, Linear map, Distribution (mathematics), Bijection, Mathematics - Probability, Analytic function
Abstract: We consider the framework of an operator-valued noncommutative probability space over a unital C*-algebra B. We show how for a B-valued distribution \mu one can define convolution powers with respect to free additive convolution and with respect to Boolean convolution, where the exponent considered in the power is a suitably chosen linear map \eta from B to B, instead of being a non-negative real number. More precisely, the Boolean convolution power is defined whenever \eta is completely positive, while the free additive convolution power is defined whenever \eta - 1 is completely positive (where 1 stands for the identity map on B). In connection to these convolution powers we define an evolution semigroup related to the Boolean Bercovici-Pata bijection. We prove several properties of this semigroup, including its connection to the B-valued free Brownian motion. We also obtain two results on the operator-valued analytic function theory related to the free additive convolution powers with exponent \eta. One of the results concerns analytic subordination for B-valued Cauchy-Stieltjes transforms. The other gives a B-valued version of the inviscid Burgers equation, which is satisfied by the Cauchy-Stieltjes transform of a B-valued free Brownian motion., Comment: 33 pages, no figures more...
Published: 2012
Full Text: View/download PDF

21. Exactness of the Fock Space Representation of the q-Commutation Relations

Author: Matthew Kennedy and Alexandru Nica
Subjects: Pure mathematics, Mathematics::Operator Algebras, 010102 general mathematics, Mathematics - Operator Algebras, Complex system, Statistical and Nonlinear Physics, 16. Peace & justice, 46L05, 46L10, 46L54, 01 natural sciences, Functional Analysis (math.FA), Fock space, Mathematics - Functional Analysis, symbols.namesake, Cuntz algebra, Von Neumann algebra, 0103 physical sciences, FOS: Mathematics, symbols, Interval (graph theory), 010307 mathematical physics, 0101 mathematics, Operator Algebras (math.OA), Representation (mathematics), Mathematical Physics, Mathematics
Abstract: We show that for all q in the interval (-1,1), the Fock representation of the q-commutation relations can be unitarily embedded into the Fock representation of the extended Cuntz algebra. In particular, this implies that the C*-algebra generated by the Fock representation of the q-commutation relations is exact. An immediate consequence is that the q-Gaussian von Neumann algebra is weakly exact for all q in the interval (-1,1)., 20 pages more...
Published: 2011
Full Text: View/download PDF

22. Enumerative Properties of NC (B) (p,q)

Author: Ion Oancea, Alexandru Nica, and Ian P. Goulden
Subjects: Combinatorics, Discrete mathematics, Polynomial, Mathematics::Combinatorics, Noncrossing partition, Lattice (group), Generating function, Discrete Mathematics and Combinatorics, Rank (graph theory), Annulus (mathematics), Möbius function, Partially ordered set, Mathematics
Abstract: We determine the rank generating function, the zeta polynomial and the Mobius function for the poset NC(B)(p, q) of annular non-crossing partitions of type B, where p and q are two positive integers. We give an alternative treatment of some of these results in the case q = 1, for which this poset is a lattice. We also consider the general case of multiannular noncrossing partitions of type B, and prove that this reduces to the cases of non-crossing partitions of type B in the annulus and the disc. more...
Published: 2011
Full Text: View/download PDF

23. Hopf algebras and the logarithm of the $S$-transform in free probability

Author: Alexandru Nica and Mitja Mastnak
Subjects: Combinatorics, Symmetric function, Power series, Logarithm, Noncrossing partition, Applied Mathematics, General Mathematics, Multiplicative function, Free probability, Hopf algebra, Noncommutative geometry, Mathematics
Abstract: Let k be a positive integer and let G k denote the set of all joint distributions of k-tuples (a 1 ,..., a k ) in a noncommutative probability space (A, ϕ) such that ϕ(a 1 ) = ··· = ϕ(a k ) = 1. G k is a group under the operation of the free multiplicative convolution . We identify (G k , ) as the group of characters of a certain Hopf algebra y (k) . Then, by using the log map from characters to infinitesimal characters of y (k) , we introduce a transform LS μ for distributions μ ∈ G k . LS μ is a power series in k noncommuting indeterminates z 1 ,..., z k ; its coefficients can be computed from the coefficients of the R-transform of μ by using summations over chains in the lattices NC(n) of noncrossing partitions. The LS-transform has the "linearizing" property that LS μν = LS μ + LS ν , ∀ μ , ν ∈ G k such that μ ν = ν μ. In the particular case k = 1 one has that y (1) is naturally isomorphic to the Hopf algebra Sym of symmetric functions and that the LS-transform is very closely related to the logarithm of the S-transform of Voiculescu by the formula LS μ (z) = ―z log S μ (z), ∀μ ∈ G 1 . In this case the group (G 1 , ) can be identified as the group of characters of Sym, in such a way that the S-transform, its reciprocal 1/S and its logarithm log S relate in a natural sense to the sequences of complete, elementary and, respectively, power sum symmetric functions. more...
Published: 2010
Full Text: View/download PDF

24. Non-crossing linked partitions, the partial order ≪ on 𝑁𝐶(𝑛), and the 𝑆-transform

Author: Alexandru Nica
Subjects: Combinatorics, Applied Mathematics, General Mathematics, Bijection, Free probability, Random variable, S transform, Reciprocal, Mathematics
Abstract: The paper establishes a connection between two recent combinatorial developments in free probability: the non-crossing linked partitions introduced by Dykema in 2007 to study the S S -transform, and the partial order ≪ \ll on N C ( n ) NC(n) introduced by Belinschi and Nica in 2008 in order to study relations between free and Boolean probability. More precisely, one has a canonical bijection between N C L ( n ) NCL(n) (the set of all non-crossing linked partitions of { 1 , … , n } \{ 1, \ldots , n \} ) and the set { ( α , β ) ∣ α , β ∈ N C ( n ) , α ≪ β } \{ ( \alpha , \beta ) \mid \alpha , \beta \in NC(n), \ \alpha \ll \beta \} . As a consequence of this bijection, one gets an alternative description of Dykema’s formula expressing the moments of a non-commutative random variable a a in terms of the coefficients of the reciprocal S S -transform 1 / S a 1/S_a . Moreover, due to the Boolean features of ≪ \ll , this formula can be simplified to a form which resembles the moment-cumulant formula from c c -free probability. more...
Published: 2009
Full Text: View/download PDF

25. Multi-variable subordination distributions for free additive convolution

Author: Alexandru Nica
Subjects: Subordination distribution, 46L54, 05A18, Space (mathematics), 01 natural sciences, Convolution, Fock space, 010104 statistics & probability, Integer, Joint probability distribution, Operator model on full Fock space, R-transform, FOS: Mathematics, 0101 mathematics, Operator Algebras (math.OA), Brownian motion, Mathematics, Discrete mathematics, 010102 general mathematics, Probability (math.PR), Mathematics - Operator Algebras, Divisibility rule, 16. Peace & justice, Free additive convolution, Distribution (mathematics), Non-crossing partition, Mathematics - Probability, Analysis
Abstract: Let k be a positive integer and let D_k denote the space of joint distributions for k-tuples of selfadjoint elements in C*-probability space. The paper studies the concept of "subordination distribution of \mu \boxplus \nu with respect to \nu" for \mu, \nu \in D_k, where \boxplus is the operation of free additive convolution on D_k. The main tools used in this study are combinatorial properties of R-transforms for joint distributions and a related operator model, with operators acting on the full Fock space Multi-variable subordination turns out to have nice relations to a process of evolution towards \boxplus-infinite divisibility on D_k that was recently found by Belinschi and Nica (arXiv:0711.3787). Most notably, one gets better insight into a connection which this process was known to have with free Brownian motion., Comment: Minor modifications and reference added to 1st version. 34 pages, no figures more...
Published: 2009
Full Text: View/download PDF

26. FREE BROWNIAN MOTION AND EVOLUTION TOWARDS ⊞-INFINITE DIVISIBILITY FOR k-TUPLES

Author: Serban T. Belinschi and Alexandru Nica
Subjects: Combinatorics, General Mathematics, Bijection, Tuple, Brownian motion, Infinite divisibility, Mathematics
Abstract: Let [Formula: see text] be the space of non-commutative distributions of k-tuples of self-adjoint elements in a C*-probability space. For every t ≥ 0 we consider the transformation [Formula: see text] defined by [Formula: see text] where ⊞ and ⊎ are the operations of free additive convolution and respectively of Boolean convolution on [Formula: see text]. We prove that 𝔹s ◦ 𝔹t = 𝔹s + t, for all s, t ≥ 0. For t = 1, we prove that [Formula: see text] is precisely the set [Formula: see text] of distributions in [Formula: see text] which are infinitely divisible with respect to ⊞, and that the map [Formula: see text] coincides with the multi-variable Boolean Bercovici–Pata bijection put into evidence in our previous paper [1]. Thus for a fixed [Formula: see text], the process {𝔹t(μ)|t ≥ 0} can be viewed as some kind of "evolution towards ⊞-infinite divisibility". On the other hand, we put into evidence a relation between the transformations ⊞t and free Brownian motion. More precisely, we introduce a map [Formula: see text] which transforms the free Brownian motion started at an arbitrary [Formula: see text] into the process {𝔹t(μ)|t ≥ 0} for μ = Φ(ν). more...
Published: 2009
Full Text: View/download PDF

27. η-series and a Boolean Bercovici–Pata bijection for bounded k-tuples

Author: Serban T. Belinschi and Alexandru Nica
Subjects: Discrete mathematics, Mathematics(all), Free probability, Series (mathematics), General Mathematics, 010102 general mathematics, Multiplicative function, Space (mathematics), 01 natural sciences, Convolution, Combinatorics, Free harmonic analysis, 010104 statistics & probability, Bounded function, R-transform, Infinite divisibility, Bijection, 0101 mathematics, Connection (algebraic framework), Random variable, Non-crossing partitions, η-series, Mathematics
Abstract: Let Dc(k) be the space of (non-commutative) distributions of k-tuples of selfadjoint elements in a C∗-probability space. On Dc(k) one has an operation ⊞ of free additive convolution, and one can consider the subspace Dcinf-div(k) of distributions which are infinitely divisible with respect to this operation. The linearizing transform for ⊞ is the R-transform (one has Rμ⊞ν=Rμ+Rν, ∀μ,ν∈Dc(k)). We prove that the set of R-transforms {Rμ|μ∈Dcinf-div(k)} can also be described as {ημ|μ∈Dc(k)}, where for μ∈Dc(k) we denote ημ=Mμ/(1+Mμ), with Mμ the moment series of μ. (The series ημ is the counterpart of Rμ in the theory of Boolean convolution.) As a consequence, one can define a bijection B:Dc(k)→Dcinf-div(k) via the formula(I)RB(μ)=ημ,∀μ∈Dc(k). We show that B is a multi-variable analogue of a bijection studied by Bercovici and Pata for k=1, and we prove a theorem about convergence in moments which parallels the Bercovici–Pata result. On the other hand we prove the formula(II)B(μ⊠ν)=B(μ)⊠B(ν), with μ,ν considered in a space Dalg(k)⊇Dc(k) where the operation of free multiplicative convolution ⊠ always makes sense. An equivalent reformulation of (II) is that(III)ημ⊠ν=ημην,∀μ,ν∈Dalg(k), where is an operation on series previously studied by Nica and Speicher, and which describes the multiplication of free k-tuples in terms of their R-transforms. Formula (III) shows that, in a certain sense, η-series behave in the same way as R-transforms in connection to the operation of multiplication of free k-tuples of non-commutative random variables. more...
Published: 2008
Full Text: View/download PDF

28. Eta-diagonal distributions and infinite divisibility for R-diagonals

Author: Michael Noyes, Hari Bercovici, Kamil Szpojankowski, and Alexandru Nica
Subjects: Statistics and Probability, Diagonal, 46L54, 60E07, 05A18, 01 natural sciences, Combinatorics, 010104 statistics & probability, 60E07, Infinite divisibility, FOS: Mathematics, Mathematics - Combinatorics, 46L53, 0101 mathematics, Operator Algebras (math.OA), Mathematics, 46L54, 010102 general mathematics, Probability (math.PR), Mathematics - Operator Algebras, $\eta$-diagonal distribution, 16. Peace & justice, Free additive convolution, R-diagonal distribution, Combinatorics (math.CO), Statistics, Probability and Uncertainty, 60E10, Mathematics - Probability
Abstract: The class of R-diagonal *-distributions is fairly well understood in free probability. In this class, we consider the concept of infinite divisibility with respect to the operation $\boxplus$ of free additive convolution. We exploit the relation between free probability and the parallel (and simpler) world of Boolean probability. It is natural to introduce the concept of an eta-diagonal distribution that is the Boolean counterpart of an R-diagonal distribution. We establish a number of properties of eta-diagonal distributions, then we examine the canonical bijection relating eta-diagonal distributions to infinitely divisible R-diagonal ones. The overall result is a parametrization of an arbitrary $\boxplus$-infinitely divisible R-diagonal distribution that can arise in a C*-probability space, by a pair of compactly supported Borel probability measures on $[ 0, \infty )$. Among the applications of this parametrization, we prove that the set of $\boxplus$-infinitely divisible R-diagonal distributions is closed under the operation $\boxtimes$ of free multiplicative convolution., Comment: 33 pages more...
Published: 2016
Full Text: View/download PDF

29. Non-crossing cumulants of type B

Author: Philippe Biane, Frederick M. Goodman, and Alexandru Nica
Subjects: Algebraic combinatorics, 46L54, Applied Mathematics, General Mathematics, Multiplicative function, Mathematics - Operator Algebras, Hyperoctahedral group, Free probability, Combinatorics, 05A18, Operator algebra, Symmetric group, FOS: Mathematics, Mathematics - Combinatorics, Combinatorics (math.CO), Operator Algebras (math.OA), Cumulant, Random variable, Mathematics
Abstract: We establish connections between the lattices of non-crossing partitions of type B introduced by V. Reiner, and the framework of the free probability theory of D. Voiculescu. Lattices of non-crossing partitions (of type A, up to now) have played an important role in the combinatorics of free probability, primarily via the non-crossing cumulants of R. Speicher. Here we introduce the concept of {\em non-crossing cumulant of type B;} the inspiration for its definition is found by looking at an operation of ``restricted convolution of multiplicative functions'', studied in parallel for functions on symmetric groups (in type A) and on hyperoctahedral groups (in type B). The non-crossing cumulants of type B live in an appropriate framework of ``non-commutative probability space of type B'', and are closely related to a type B analogue for the R-transform of Voiculescu (which is the free probabilistic counterpart of the Fourier transform). By starting from a condition of ``vanishing of mixed cumulants of type B'', we obtain an analogue of type B for the concept of free independence for random variables in a non-commutative probability space., Comment: 48 pages, latex more...
Published: 2003
Full Text: View/download PDF

30. R-Diagonal Elements and Freeness With Amalgamation

Author: Alexandru Nica, Roland Speicher, and Dimitri Shlyakhtenko
Subjects: Combinatorics, Pure mathematics, Class (set theory), General Mathematics, 010102 general mathematics, 0103 physical sciences, Diagonal, 010307 mathematical physics, 0101 mathematics, Element (category theory), Free probability, 01 natural sciences, Mathematics
Abstract: The concept of R-diagonal element was introduced in [5], and was subsequently found to have applications to several problems in free probability. In this paper we describe a new approach to R-diagonality, which relies on freeness with amalgamation. The class of R-diagonal elements is enlarged to contain examples living in non-tracial *-probability spaces, such as the generalized circular elements of [7]. more...
Published: 2001
Full Text: View/download PDF

31. On the Distribution of the Area Enclosed by a Random Walk onZ2

Author: Alexandru Nica and James A. Mingo
Subjects: Path (topology), Discrete mathematics, Distribution (number theory), Degree (graph theory), 010102 general mathematics, Asymptotic distribution, Random walk, 01 natural sciences, Theoretical Computer Science, Combinatorics, Exponential formula, Computational Theory and Mathematics, Integer, 0103 physical sciences, Discrete Mathematics and Combinatorics, 0101 mathematics, 010306 general physics, Unit (ring theory), Mathematics
Abstract: LetΓ2nbe the set of paths with 2nsteps of unit length inZ2, which begin and end at (0,0). Forγ∈Γ2n, letarea(γ)∈Zdenote the oriented area enclosed byγ. We show that for every positive even integerk, there exists a rational functionRkwith integer coefficients, such that:1|Γ2n|∑γ∈Gamma;2n[area(γ)]k=Rk(n,n>2k.We calculate explicitly the degree and leading coefficient ofRk. We show how as a consequence of this (and by also using the enumeration of up-down permutations, and the exponential formula for cycles of permutations) one can derive the asymptotic distribution of the area enclosed by a random path inΓ2n. The formula for the asymptotic distribution can be stated as follows: forα more...
Published: 1998
Full Text: View/download PDF

32. Crossings of Set-Partitions and Addition Crossings of Graded-Independent Random Variables

Author: Alexandru Nica and James A. Mingo
Subjects: Combinatorics, Discrete mathematics, Tensor product, Formal power series, General Mathematics, Linear form, Generating function, Connection (algebraic framework), Random variable, Independence (probability theory), Exponential function, Mathematics
Abstract: We consider a q-deformation, introduced in [7], of the cumulants associated with a linear functional on polynomials; combinatorially, the deformation is defined using crossing numbers of set-partitions. The paper is concerned with the case q = -1. We show that if the linear functional μ : C[X] → C is symmetric (i.e.μ(Xn) = 0 for n odd), then the exponential generating function of the even (-1)-cumulants of μ is equal to [Formula: see text], (as a formal power series in z). We discuss the connection of this fact with the form of independence for (non-commutative) random variables which corresponds to the operation of Z2-graded tensor product. more...
Published: 1997
Full Text: View/download PDF

33. [Untitled]

Author: Roland Speicher and Alexandru Nica
Subjects: Combinatorics, symbols.namesake, Algebra and Number Theory, Fourier transform, Group (mathematics), Multiplicative function, Structure (category theory), symbols, Discrete Mathematics and Combinatorics, Combinatorial proof, Multiplication, Random variable, Mathematics
Abstract: We describe the structure of the group of normalized multiplicative functions on lattices of non-crossing partitions. As an application, we give a combinatorial proof of a theorem of D. Voiculescu concerning the multiplication of free random variables more...
Published: 1997
Full Text: View/download PDF

34. 𝑅-diagonal pairs—A common approach to Haar unitaries and circular elements

Author: Alexandru Nica and Roland Speicher
Published: 1996
Full Text: View/download PDF

35. Crossings and embracings of set-partitions and q-analogues of the logarithm of the Fourier transform

Author: Alexandru Nica
Subjects: Discrete mathematics, Mathematics::Combinatorics, Logarithm, Discrete-time Fourier transform, Fourier inversion theorem, Convolution of probability distributions, Convolution, Theoretical Computer Science, Combinatorics, symbols.namesake, Discrete Fourier transform (general), Exponential formula, Fourier transform, symbols, Discrete Mathematics and Combinatorics, Mathematics
Abstract: We describe the relation between the q-analogue of the exponential formula found by Gessel [8], and the q-analogue of the convolution of probability distributions studied in [12].
Published: 1996
Full Text: View/download PDF

36. R-Transforms of Free Joint Distributions and Non-crossing Partitions

Author: Alexandru Nica
Subjects: Combinatorics, Free convolution, Free product, Joint probability distribution, Lattice (order), Inverse, Free probability, Cumulant, Random variable, Analysis, Mathematics
Abstract: We introduce an extension of the notion of R-transform , defined by D. Voiculescu, to ( free ) joint distributions , i.e., normalized linear functionals on algebras of non-commutative polynomials in several indeterminates. We point out that the R -transform has good behavior with respect to the operations of free product and free convolution of joint distributions. We prove that the explicit computation of the inverse- R -transform of a joint distribution is done via a formula of summation over the lattice of non-crossing partitions, which shows that the R -transform is the operator-theoretic counterpart of the “free cumulants” considered in the combinatorial approach of R. Speicher. Moreover, in connection to the equivariance of the multidimensional R -transform under rotations, we show that a natural free analogue of a classical result about rotations of independent random variables is holding. more...
Published: 1996
Full Text: View/download PDF

37. On the multiplication of free N -tuples of noncommutative random variables

Author: Alexandru Nica and Roland Speicher
Subjects: Discrete mathematics, Free convolution, Formal power series, Operator algebra, Noncrossing partition, Joint probability distribution, General Mathematics, Multiplication, Noncommutative geometry, Random variable, Mathematics
Abstract: Let a1, , a n , b 1 , , b n be random variables in a noncommutative probability space, such that a1, , a n is free from b1, , b n . We show how the joint distribution of the n-tuple (a1b1, , a n b n ) can be described in terms of the joint distributions of (a1, , a n )a nd ( b 1 , , b n ), by using the combinatorics of the n-dimensional R-transform. We point out a few applications that can be easily derived from our result, concerning the left-and-right translation with a semicircular element (see Sections 1.6-1.10) and the compression with a projection (see Sections 1.11-1.14) of an n-tuple of noncommutative random variables. A different approach to two of these applications is presented by Dan Voiculescu in an Appendix to the paper. Introduction. The theory of free random variables was developed in a se- quence of papers of D. Voiculescu (see (17), or the recent survey in (16)), as an instrument for approaching free products of operator algebras. Its particular aspect addressed in the present paper is the one concerning the addition and multiplica- tion of free random variables; as shown by Voiculescu in (13), (14), a powerful method in the study of these operations is the use of transforms that convert them (respectively) into addition and multiplication of complex analytic func- tions, or, in an algebraic framework, of formal power series in an indeterminate z. The precise definitions of these transforms (called R-transform for the addition problem and S-transform for the multiplication problem) will be reviewed in the Sections 1.2, 1.3 below. In the present paper we are pursuing a combination of two ideas that have appeared recently in the study of the R- and S-transforms. The first idea is that the connection between the R- and the S-transform is closer than one might suspect at first glance. A way of making this precise was pointed out in our paper (6), in the form of the equation S( )= ( R ( )) for a distribution with nonvan- ishing mean, and where is a combinatorial object with a precise significance ("the Fourier transform for multiplicative functions on noncrossing partitions"). A byproduct of our result in (6) is the remark that the multiplication of free more...
Published: 1996
Full Text: View/download PDF

38. Double-ended queues and joint moments of left-right canonical operators on full Fock space

Author: Alexandru Nica and Mitja Mastnak
Subjects: Pure mathematics, 46L54, General Mathematics, 010102 general mathematics, Mathematics - Operator Algebras, Free probability, Space (mathematics), 01 natural sciences, Noncommutative geometry, Fock space, 010104 statistics & probability, Simple (abstract algebra), Line (geometry), FOS: Mathematics, Order (group theory), 0101 mathematics, Operator Algebras (math.OA), Independence (probability theory), Mathematics
Abstract: We follow the guiding line offered by canonical operators on the full Fock space, in order to identify what kind of cumulant functionals should be considered for the concept of bi-free independence introduced in the recent work of Voiculescu. By following this guiding line we arrive to consider, for a general noncommutative probability space (A, phi), a family of "(l,r)-cumulant functionals" which enlarges the family of free cumulant functionals of the space. In the motivating case of canonical operators on the full Fock space we find a simple formula for a relevant family of (l,r)-cumulants of a (2d)-tuple (A_1, ..., A_d, B_1, ..., B_d), with A_1, ... , A_d canonical operators on the left and B_1, ... , B_d canonical operators on the right. This extends a known one-sided formula for free cumulants of A_1, ..., A_d, which establishes a basic operator model for the R-transform of free probability., Comment: In this (final) version, the introduction was re-written to better show the motivation for the question considered in the paper more...
Published: 2013
Full Text: View/download PDF

39. Free probability aspect of irreducible meandric systems, and some related observations about meanders

Author: Alexandru Nica
Subjects: Statistics and Probability, Pure mathematics, Computer Science::Information Retrieval, Applied Mathematics, 010102 general mathematics, Astrophysics::Instrumentation and Methods for Astrophysics, Computer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing), Statistical and Nonlinear Physics, Free probability, 01 natural sciences, Lattice (order), Linear form, 0103 physical sciences, Meander, Computer Science::General Literature, 010307 mathematical physics, 0101 mathematics, Random variable, Mathematical Physics, Mathematics
Abstract: We consider the concept of irreducible meandric system introduced by Lando and Zvonkin. We place this concept in the lattice framework of [Formula: see text]. As a consequence, we show that the even generating function for irreducible meandric systems is the [Formula: see text]-transform of [Formula: see text], where [Formula: see text] and [Formula: see text] are classically (commuting) independent random variables, and each of [Formula: see text] has centred semicircular distribution of variance [Formula: see text]. Following this point of view, we make some observations about the symmetric linear functional on [Formula: see text] which has [Formula: see text]-transform given by the even generating function for meanders. more...
Published: 2016
Full Text: View/download PDF

40. ON A GROUPOID CONSTRUCTION FOR ACTIONS OF CERTAIN INVERSE SEMIGROUPS

Author: Alexandru Nica
Subjects: Mathematics::Operator Algebras, Semigroup, General Mathematics, Mathematics - Operator Algebras, Group algebra, Automorphism, Functional Analysis (math.FA), Mathematics - Functional Analysis, Algebra, Inverse semigroup, Algebraic theory, Bicyclic semigroup, FOS: Mathematics, Inverse element, Locally compact space, Operator Algebras (math.OA), Mathematics
Abstract: We consider a version of the notion of F-inverse semigroup (studied in the algebraic theory of inverse semigroups). We point out that an action of such an inverse semigroup on a locally compact space has associated a natural groupoid construction, very similar to the one of a transformation group. We discuss examples related to Toeplitz algebras on subsemigroups of discrete groups,to Cuntz-Krieger algebras, and to crossed-products by partial automorphisms in the sense of Exel., Comment: 27 pages, LATEX more...
Published: 1994
Full Text: View/download PDF

41. Gaussian random matrices

Author: Roland Speicher and Alexandru Nica
Subjects: Wishart distribution, Combinatorics, symbols.namesake, Covariance matrix, Gaussian, symbols, Marchenko–Pastur distribution, Semicircle law, Free probability, Random matrix, Gaussian random field, Mathematics
Published: 2006
Full Text: View/download PDF

42. Basic combinatorics II: Möbius inversion

Author: Alexandru Nica and Roland Speicher
Subjects: Combinatorics, Discrete mathematics, Extremal combinatorics, symbols.namesake, Algebraic combinatorics, Graded poset, symbols, Möbius function, Free probability, Combinatorics and physics, Mobius inversion, Mathematics, Riemann zeta function
Published: 2006
Full Text: View/download PDF

43. Sums of free random variables

Author: Alexandru Nica and Roland Speicher
Subjects: Combinatorics, Discrete mathematics, Free convolution, Stochastic process, Free probability, Random variable, Algebra of random variables, Mathematics, Bell number
Published: 2006
Full Text: View/download PDF

44. R-diagonal elements

Author: Alexandru Nica and Roland Speicher
Subjects: Combinatorics, Physics, Diagonal
Published: 2006
Full Text: View/download PDF

45. Free cumulants: definition and basic properties

Author: Alexandru Nica and Roland Speicher
Subjects: Combinatorics, symbols.namesake, Fourier transform, Bernoulli distribution, Semi invariant, symbols, Element (category theory), Free probability, Cumulant, Mathematics
Published: 2006
Full Text: View/download PDF

46. Free product of *-probability spaces

Author: Alexandru Nica and Roland Speicher
Subjects: Combinatorics, Discrete mathematics, Partial isometry, Matrix (mathematics), Free product, Isometry, Hadamard product, Free probability, Projection (linear algebra), Mathematics
Published: 2006
Full Text: View/download PDF

47. More on the one-dimensional boxed convolution

Author: Alexandru Nica and Roland Speicher
Subjects: Algebra, Orbit (control theory), Free probability, Algorithm, S transform, Convolution, Mathematics
Published: 2006
Full Text: View/download PDF

48. Products of free random variables

Author: Alexandru Nica and Roland Speicher
Subjects: Statistics, Random variable, Mathematics
Published: 2006
Full Text: View/download PDF

49. Lectures on the Combinatorics of Free Probability

Author: Alexandru Nica and Roland Speicher
Abstract: Free Probability Theory studies a special class of 'noncommutative'random variables, which appear in the context of operators on Hilbert spaces and in one of the large random matrices. Since its emergence in the 1980s, free probability has evolved into an established field of mathematics with strong connections to other mathematical areas, such as operator algebras, classical probability theory, random matrices, combinatorics, representation theory of symmetric groups. Free probability also connects to more applied scientific fields, such as wireless communication in electrical engineering. This 2006 book gives a self-contained and comprehensive introduction to free probability theory which has its main focus on the combinatorial aspects. The volume is designed so that it can be used as a text for an introductory course (on an advanced undergraduate or beginning graduate level), and is also well-suited for the individual study of free probability. more...
Published: 2006
Full Text: View/download PDF

50. Definition and basic properties of free independence

Author: Alexandru Nica and Roland Speicher
Subjects: media_common.quotation_subject, Economics, Mathematical economics, Independence, media_common
Published: 2006
Full Text: View/download PDF

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Publication Type

Journal

Database

Publisher

76 results on '"Alexandru, Nica"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources