Von Neumann-Morgenstern Stable Sets in Matching Problems

The following properties of the core of a one well-known: (i) the core is non-empty; (ii) the core is a lattice; and (iii) the set of unmatched agents is identical for any two matchings belonging to the core. The literature on two-sided matching focuses almost exclusively on the core and studies extensively its properties. Our main result is the following characterization of (von Neumann-Morgenstern) stable sets in one-to-one matching problem only if it is a maximal set satisfying the following properties : (a) the core is a subset of the set; (b) the set is a lattice; (c) the set of unmatched agents is identical for any two matchings belonging to the set. Furthermore, a set is a stable set if it is the unique maximal set satisfying properties (a), (b) and (c). We also show that our main result does not extend from one-to-one matching problems to many-to-one matching problems.

Matching Markets under (In)complete Information

We are the first to introduce incomplete information to centralized many-to-one matching markets such as those to entry-level labor markets or college admissions. This is important because in real life markets (i) any agent is uncertain about the other agents' true preferences and (ii) most entry-level matching is many-to-one (and not one-to-one). We show that for stable (matching) mechanisms there is a strong and surprising link between Nash equilibria under complete information and Bayesian Nash equilibria under incomplete information. That is,given a common belief, a strategy profile is a Bayesian Nash equilibrium under incomplete information in a stable mechanism if and only if, for any true profile in the support of the common belief, the submitted profile is a Nash equilibrium under complete information at the true profile in the direct preference revelation game induced by the stable mechanism. This result may help to explain the success of stable mechanisms in these markets.

Censure.cn : Google s’attaque au marché chinois

Étude de cas

Using Google Analytics to evaluate an email information literacy program for medical and dental students

Objectives: An email information literacy program has been effective for over a decade at Université de Montréal’s Health Library. Students periodically receive messages highlighting the content of guides on the library’s website. We wish to evaluate, using Google Analytics, the effects of the program on specific webpage statistics. Using the data collected, we may pinpoint popular guides as well as others that need improvement. Methods: In the program, first and second-year medical (MD) or dental (DMD) students receive eight bi-monthly email messages. The DMD mailing list also includes graduate students and professors. Enrollment to the program is optional for MDs, but mandatory for DMDs. Google Analytics (GA) profiles have been configured for the libraries websites to collect visitor statistics since June 2009. The GA Links Builder was used to design unique links specifically associated with the originating emails. This approach allowed us to gather information on guide usage, such as the visitor’s program of study, duration of page viewing, number of pages viewed per visit, as well as browsing data. We also followed the evolution of clicks on GA unique links over time, as we believed that users may keep the library's emails and refer to them to access specific information. Results: The proportion of students who actually clicked the email links was, on average, less than 5%. MD and DMD students behaved differently regarding guide views, number of pages visited and length of time on the site. The CINAHL guide was the most visited for DMD students whereas MD students consulted the Pharmaceutical information guide most often. We noted that some students visited referred guides several weeks after receiving messages, thus keeping them for future reference; browsing to additional pages on the library website was also frequent. Conclusion: The mitigated success of the program prompted us to directly survey students on the format, frequency and usefulness of messages. The information gathered from GA links as well as from the survey will allow us to redesign our web content and modify our email information literacy program so that messages are more attractive, timely and useful for students.

Three works on religious themes : psalmus 150, string quartet on the life of Saint John Paul II and symphony “The Redemption”

Dans cette dissertation, je présente trois pièces sur des thèmes religieux composées au cours de ma maîtrise, ainsi que leur analyse : Psalmus 150 pour chœur de jeunes à trois voix, chœur d'adultes à huit voix et orgue ou piano ; Quatuor à Cordes sur la vie de Saint Jean-Paul II ; et la Symphonie « La Rédemption » pour orchestre et chœur. Malgré les particularités de chacune, elles présentent des aspects communs. L'idée principale des compositions fut d'éviter la rupture avec la tradition tout en apportant des nouvelles idées aux pièces, et de souligner l'importance de ma recherche sur la beauté. À cet égard, certaines techniques contemporaines, ainsi que les sonorités médiévales des quintes et octaves parallèles, furent utilisées en accord avec un langage tonal / modal qui demeure la base des trois compositions. Le chant Grégorien fut aussi une importante caractéristique de ces compositions. Pour mieux comprendre les analyses des œuvres, deux techniques seront expliquées, la douce toile de dissonances linéaires et l'harmonie d'accords parfaits majeurs. L'analyse de chaque pièce est divisée en deux parties. La première est une vision générale et la deuxième est plus détaillée. À la fin, les connaissances acquises par la composition des ces œuvres seront résumées et l'importance intemporelle de la beauté sera réaffirmée.