Online Journals: Utility of ToCs vs. Fulltext

The Caltech Library System (CLS) has maintained an extensive list of online journal websites for several years. The online journal list has grown to over 3000 entries, representing a mixture of free and subscription-based fulltext journals, as well as websites featuring tables of contents and abstracts. During the winter of 1999/2000, the online journals list was converted to an online journals database. Additional user functionality was added, without loss of previous features. In a previous study, search engines were employed to map the adoption rates of online journals into the web pages of research groups and individuals on the Caltech campus. It was established that the vast majority of online journal use on-campus was through the access avenues presented by the library, the online catalog and the online journals database. One of the new features introduced in the online journals database was an ability to limit displays to journals containing fulltext. Anecdotal evidence has been less than clear-cut with regard to the utility of non-fulltext resources. This study will allow for a thorough analysis of the question with hard data. It should be feasible to determine if there are discipline-based preferences or if personal preferences are the controlling factor. Analysis of the web server logs will also allow for a direct comparison of user preferences for searching and browsing. Again, we expect to be able to determine if there is a subject-specific bias or if behaviors are more individually idiosyncratic. Results of the study will inform the further development of the CLS online journal efforts - database development, online journal promotion, new candidates for licensing. The technologies employed in this project are well documented and may be exploited by other libraries seeking to gather empirical data for collection decisions and web development efforts

Ariel - Volume 12(13) Number 4

Co-Editors Gary Fishbein Lynn Solomon Business Manager Rich Davis Assistant Business Manager Jeff Lavanier Layout Editors Paul J. Berlin Tracy A. Glauser Photography Editor Ben Alma

Ariel - Volume 9 Number 1

Executive Editor Emily Wofford Business Manager Fredric Jay Matlin University News John Patrick Welch World News George Robert Coar Editorial Editor Steve Levine Feature Brad Feldstein Mark Rubin Graphics Steve Hulkower Photo Rick Spaide Circulation Lee Wugofsk

TEDI: the TripleSpec Exoplanet Discovery Instrument

The TEDI (TripleSpec - Exoplanet Discovery Instrument) will be the first instrument fielded specifically for finding low-mass stellar companions. The instrument is a near infra-red interferometric spectrometer used as a radial velocimeter. TEDI joins Externally Dispersed Interferometery (EDI) with an efficient, medium-resolution, near IR (0.9 - 2.4 micron) echelle spectrometer, TripleSpec, at the Palomar 200" telescope. We describe the instrument and its radial velocimetry demonstration program to observe cool stars.Comment: 6 Pages, To Appear in SPIE Volume 6693, Techniques and Instrumentation for Detection of Exoplanets II

The IPAC Image Subtraction and Discovery Pipeline for the intermediate Palomar Transient Factory

We describe the near real-time transient-source discovery engine for the intermediate Palomar Transient Factory (iPTF), currently in operations at the Infrared Processing and Analysis Center (IPAC), Caltech. We coin this system the IPAC/iPTF Discovery Engine (or IDE). We review the algorithms used for PSF-matching, image subtraction, detection, photometry, and machine-learned (ML) vetting of extracted transient candidates. We also review the performance of our ML classifier. For a limiting signal-to-noise ratio of 4 in relatively unconfused regions, "bogus" candidates from processing artifacts and imperfect image subtractions outnumber real transients by ~ 10:1. This can be considerably higher for image data with inaccurate astrometric and/or PSF-matching solutions. Despite this occasionally high contamination rate, the ML classifier is able to identify real transients with an efficiency (or completeness) of ~ 97% for a maximum tolerable false-positive rate of 1% when classifying raw candidates. All subtraction-image metrics, source features, ML probability-based real-bogus scores, contextual metadata from other surveys, and possible associations with known Solar System objects are stored in a relational database for retrieval by the various science working groups. We review our efforts in mitigating false-positives and our experience in optimizing the overall system in response to the multitude of science projects underway with iPTF.Comment: 66 pages, 21 figures, 7 tables, accepted by PAS

Spherical Formulation for Diagramatic Evaluations on a Manifold with Boundary

The mathematical formalism necessary for the diagramatic evaluation of quantum corrections to a conformally invariant field theory for a self-interacting scalar field on a curved manifold with boundary is considered. The evaluation of quantum corrections to the effective action past one-loop necessitates diagramatic techniques. Diagramatic evaluations and higher loop-order renormalisation can be best accomplished on a Riemannian manifold of constant curvature accommodating a boundary of constant extrinsic curvature. In such a context the stated evaluations can be accomplished through a consistent interpretation of the Feynman rules within the spherical formulation of the theory for which the method of images allows. To this effect, the mathematical consequences of such an interpretation are analyzed and the spherical formulation of the Feynman rules on the bounded manifold is, as a result, developed.Comment: 12 pages, references added. To appear in Classical and Quantum Gravit

Ariel - Volume 9 Number 4

Executive Editor Emily Wofford Business Manager Fredric Jay Matlin University News John Patrick Welch World News George Robert Coar Editorials Editor Steve Levine Features Mark Rubin Brad Feldstein Sports Editor EIi Saleeby Circulation Victor Onufreiczuk Lee Wugofski Graphics and Art Steve Hulkower Commons Editor Brenda Peterso

Perturbative Evaluation of Interacting Scalar Fields on a Curved Manifold with Boundary

The effects of quantum corrections to a conformally invariant scalar field theory on a curved manifold of positive constant curvature with boundary are considered in the context of a renormalisation procedure. The renormalisation of the theory to second order in the scalar self-coupling pursued herein involves explicit calculations of up to third loop-order and reveals that, in addition to the renormalisation of the scalar self-coupling and scalar field, the removal of all divergences necessitates the introduction of conformally non-invariant counterterms proportional to $R\Phi^2$ and $K\Phi^2$ in the bare scalar action as well as counterterms proportional to $RK^2$, $R^2$ and $RK$ in the gravitational action. The substantial backreaction effects and their relevance to the renormalisation procedure are analysed.Comment: 25 pages, 1 figure. Minor elucidations in the Appendix regarding the cut-off $N_0$ and in p.4 regarding the gravitational action. Certain reference-related ommission corrected. To appear in Classical and Quantum Gravit