The Rolex Learning Center at EPFL: a new building for a new vision in collection development

The reunification of 10 faculty libraries inside the new Rolex Learning Center at EPFL was a perfect opportunity to rethink which collections should be put forward in an environment that is organized primarly around the working and living space of the users. "Collection development" has shifted from a simple selection of content added to collections to a selection of the best way of access to relevent content. Electronic books allow on-demand access in an even more cost and ressource-efficient way. We discuss how the EPFL Library is implementing its e-books collection to allow for on-demand rental or buying of titles

EPFL Library Link: a Firefox plug-in to increase collection visibility ?

EPFL Library Link is a tool that was originally developed to help subject librarians in their selection process by displaying title availability in the catalog directly on provider web pages and databases. It soon became clear, however, that the real-time availability of library titles on web sites such as Amazon.com would help patrons seeking access to a particular book but unaware that this book may already be available in the library network. Thus, instead of keeping on trying to drive patrons to the OPAC, the OPAC is brought to the users where they actually are (e.g. on Amazon). EPFL Library Link is currently in development to implement this feature

Étude des fondements physiques possibles des concepts numériques utilisés dans les méthodes d'acoustique géométrique

The subject of the work presented here is the study of the acoustical ray method, which aims at describing a pressure field by an analogy with light rays. The concept of a wave is therefore replaced by the concept of "acoustical rays", whose paths through the domain under study are described by their reflections off the obstacles they encounter. The postulate of specular reflection is made : only the direct neighborhood of the point where the incoming ray meets the obstacle is taken into account. When absorption is considered at that particular point, it is represented by a localized acoustic impedance. Such a method, also called geometrical acoustics, is widely used for the computation of the acoustical characteristics of a room, for example the reverberation time in a concert hall, etc. In this case, the dimensions of the domain under study are several orders of magnitude larger than the considered wavelengths. Moreover, the information sought resides mostly in the first reflections. In these circumstances, the quality of prediction obtained is satisfactory, and is experimentally verified. Conversely, in geometries of smaller size and when a solution combining a greater number of reflections is required, simulations show a discrepancy between results obtained with the geometrical solution and those obtained via another method, such as finite elements. These differences, mostly in terms of frequency shifts of resonance peaks, are particularly visible in positions near the walls of the domain under study. With the aim of eventually finding ways to improve the prediction quality of the geometrical method, the work proposes a substitute for the intuitive origin of image sources. In fact, a parallel with a form of a solution of the Helmholtz equation by the integral method is shown. With this novel representation, image sources appear to have a more rigorous base than with the optical analogy. Before being able to improve a method, a deep understanding of its foundations is required. Here, the study of two phenomena occurring in reflection problems is proposed, and their influence on the results obtained with the geometrical method is observed. First, the very concept of image sources, which give rise to acoustical rays, is studied. By doing this, an a priori new description of image sources is proposed, which shows a close parallel between the representation of the acoustical field by a sum of rays emitted by image sources and a solution obtained by the integral method. Secondly, the validity of non locally reacting wave reflection, which is implied in geometrical acoustical methods, is studied. This is achieved by replacing the specular (local) coefficient classically used to describe reflection upon an obstacle with a non local coefficient, obtained by identification from an integral representation. Both methods are evaluated in geometries of growing complexity : spaces bounded by one, then two walls, and finally closed by several walls. This enables the study of an increasing number of reflections

Le nouveau Rolex Learning Center

Conçu par le bureau d’architecture japonais SANAA, le Rolex Learning Center est le nouveau bâtiment phare du campus de l’EPFL. Inauguré le 22 février 2010, il abrite sur ses 15'000 m2: la Bibliothèque de l’EPFL, ses collections, bureaux et surtout 900 places de travail pour les étudiants (zone silence, zone calme et bulles de travail en groupe), des services (restaurants, banque, librairie), une salle de spectacles, un éditeur, un laboratoire de recherche sur les technologies appliquées à la formation, des associations d'étudiants... Le bâtiment et ses services sont ouverts 7/7 jours, de 7h à 24h. Tout est pensé pour répondre aux besoins de l'utilisateur d'une "bibliothèque" au sens large: lieu de vie, lieu de travail, lieu d'interaction. Cette présentation évoque les étapes du projet RLC, son contexte dans l'histoire du campus et l'évolution de l'enseignement, ainsi que les services proposés par la nouvelle Bibliothèque de l'EPFL

Signalement des livres électroniques à l’Ecole Polytechnique Fédérale de Lausanne (EPFL)

La Bibliothèque de l'EPFL réfléchit à la problématique du signalement des livres électroniques depuis 2005, lorsqu'un catalogue ad-hoc est créé pour pallier aux difficultés d'insérer ces ouvrages dans le catalogue collectif NEBIS. Cette solution permet de cataloguer facilement les e-books, mais impose à l'utilisateur d'interroger plusieurs catalogues. Une solution avec un champ de recherche unique est donc préférable. Les outils de type "ressource discovery tools" pourraient permettre la mise en place d'une telle recherche unifiée. Cette présentation revient sur l'expérience de la bibliothèque de l'EPFL dans sa recherche d'une telle solution

Selecting and managing e-book solutions

Many collection development practices are relevant for electronic books as well as for their paper counterparts: selection, acquisition, management, cataloguing, evaluation, etc. Over the years, libraries have developed best practices and tools to tackle these issues for physical objects. But tools to handle e-books have yet to be developed. On the contrary, librarians are often overwhelmed by the disparity in e-books solutions and lack a way to rationally select the solution that best suits their needs. To start the discussion, we first present the real- life example of the selection of a new e-book provider for an academic library to suggest a systematic approach to the problem. The selection process starts with the listing of objective decision criteria (e.g. pricing and loan models, ease of integration in our catalogue, ease of use, file format, etc.), which are then used as base for a market analysis. Six major providers of comparable content (e-books mainly in English and on scientific and technical subjects) are tested against those criteria. In addition to that, the actual availability and pricing of a sample list of 3’000 representative titles is assessed by matching it to the catalogue of all surveyed providers. We thus have developed a system able to help us choose which supplier best suits our specific acquisition needs. The above method can of course be repeated for every library wishing to develop an e-books collection. But the data we have collected can also easily be extended to a shared database, from which other libraries can profit (a sort of “Global e- books in print”). Collaboration between libraries and content providers could also lead to the creation of simple tools that would help the selection process. We will also address the remaining challenges in the evaluation of e- books usage, which is critical for coherent collection development. The goal of this workshop is to share experience among the participants in the management of ebooks and to discuss the opportunity and feasability of collaborative tools to help libraries develop a coherent e-book collection

Biased efficacy estimates in phase-III dengue vaccine trials due to heterogeneous exposure and differential detectability of primary infections across trial arms.

Vaccine efficacy (VE) estimates are crucial for assessing the suitability of dengue vaccine candidates for public health implementation, but efficacy trials are subject to a known bias to estimate VE toward the null if heterogeneous exposure is not accounted for in the analysis of trial data. In light of many well-characterized sources of heterogeneity in dengue virus (DENV) transmission, our goal was to estimate the potential magnitude of this bias in VE estimates for a hypothetical dengue vaccine. To ensure that we realistically modeled heterogeneous exposure, we simulated city-wide DENV transmission and vaccine trial protocols using an agent-based model calibrated with entomological and epidemiological data from long-term field studies in Iquitos, Peru. By simulating a vaccine with a true VE of 0.8 in 1,000 replicate trials each designed to attain 90% power, we found that conventional methods underestimated VE by as much as 21% due to heterogeneous exposure. Accounting for the number of exposures in the vaccine and placebo arms eliminated this bias completely, and the more realistic option of including a frailty term to model exposure as a random effect reduced this bias partially. We also discovered a distinct bias in VE estimates away from the null due to lower detectability of primary DENV infections among seronegative individuals in the vaccinated group. This difference in detectability resulted from our assumption that primary infections in vaccinees who are seronegative at baseline resemble secondary infections, which experience a shorter window of detectable viremia due to a quicker immune response. This resulted in an artefactual finding that VE estimates for the seronegative group were approximately 1% greater than for the seropositive group. Simulation models of vaccine trials that account for these factors can be used to anticipate the extent of bias in field trials and to aid in their interpretation