Costing Reference: Issues, Approaches, and Directions for Research

The Assessing Quality in Digital Reference project is a first step toward understanding the cost of digital reference services in libraries. This article presents three measures isolated by project participants as being most useful for their immediate needs: total cost of providing digital reference service, the cost of digital reference service as a percent of the total reference budget, and the cost of reference as a percent of the total library or organizational budget. In addition, it reviews selected outstanding issues in the ongoing question of how to determine the cost of reference services in libraries and offers direction for further study toward a general cost model for information servicesInformatio

Non-Perturbative Solution of Matrix Models Modified by Trace-Squared Terms

We present a non-perturbative solution of large $N$ matrix models modified by terms of the form g(\Tr\Phi^4)^2, which add microscopic wormholes to the random surface geometry. For $g<g_t$ the sum over surfaces is in the same universality class as the $g=0$ theory, and the string susceptibility exponent is reproduced by the conventional Liouville interaction $\sim e^{\alpha_+ \phi}$. For $g=g_t$ we find a different universality class, and the string susceptibility exponent agrees for any genus with Liouville theory where the interaction term is dressed by the other branch, $e^{\alpha_- \phi}$. This allows us to define a double-scaling limit of the $g=g_t$ theory. We also consider matrix models modified by terms of the form $g O^2$, where $O$ is a scaling operator. A fine-tuning of $g$ produces a change in this operator's gravitational dimension which is, again, in accord with the change in the branch of the Liouville dressing.Comment: 26 pages, PUPT-149

Aspects of Large N Gauge Theory Dynamics as Seen by String Theory

In this paper we explore some of the features of large N supersymmetric and nonsupersymmetric gauge theories using Maldacena's duality conjectures. We shall show that the resulting strong coupling behavior of the gauge theories is consistent with our qualitative expectations of these theories. Some of these consistency checks are highly nontrivial and give additional evidence for the validity of the proposed dualities.Comment: 31 pages, LaTeX, 11 eps figures, typos correcte

Microcanonical entropy inflection points: Key to systematic understanding of transitions in finite systems

We introduce a systematic classification method for the analogs of phase transitions in finite systems. This completely general analysis, which is applicable to any physical system and extends towards the thermodynamic limit, is based on the microcanonical entropy and its energetic derivative, the inverse caloric temperature. Inflection points of this quantity signal cooperative activity and thus serve as distinct indicators of transitions. We demonstrate the power of this method through application to the long-standing problem of liquid-solid transitions in elastic, flexible homopolymers.Comment: 4 pages, 3 figure

Mid-IR Hyperspectral Imaging of Laminar Flames for 2-D Scalar Values

This work presents a new emission-based measurement which permits quantification of two-dimensional scalar distributions in laminar flames. A Michelson-based Fourier-transform spectrometer coupled to a mid-infrared camera (1.5 μm to 5.5 μm) obtained 256 × 128pixel hyperspectral flame images at high spectral (δν̃ = 0.75cm−1) and spatial (0.52 mm) resolutions. The measurements revealed line and band emission from H2O, CO2, and CO. Measurements were collected from a well-characterized partially-premixed ethylene (C2H4) flame produced on a Hencken burner at equivalence ratios, Φ, of 0.8, 0.9, 1.1, and 1.3. After describing the instrument and novel calibration methodology, analysis of the flames is presented. A single-layer, line-by-line radiative transfer model is used to retrieve path-averaged temperature, H2O, CO2 and CO column densities from emission spectra between 2.3 μm to 5.1 μm. The radiative transfer model uses line intensities from the latest HITEMP and CDSD-4000 spectroscopic databases. For the Φ = 1.1 flame, the spectrally estimated temperature for a single pixel 10 mm above burner center was T = (2318 ± 19)K, and agrees favorably with recently reported laser absorption measurements, T = (2348 ± 115)K, and a NASA CEA equilibrium calculation, T = 2389K. Near the base of the flame, absolute concentrations can be estimated, and H2O, CO2, and CO concentrations of (12.5 ± 1.7) %, (10.1 ± 1.0) %, and (3.8 ± 0.3) %, respectively, compared favorably with the corresponding CEA values of 12.8%, 9.9% and 4.1%. Spectrally-estimated temperatures and concentrations at the other equivalence ratios were in similar agreement with measurements and equilibrium calculations. 2-D temperature and species column density maps underscore the Φ-dependent chemical composition of the flames. The reported uncertainties are 95% confidence intervals and include both statistical fit errors and the propagation of systematic calibration errors using a Monte Carlo approach. Systematic errors could warrant a factor of two increase in reported uncertainties. This work helps to establish IFTS as a valuable combustion diagnostic tool

RURAL KENTUCKY’S PHYSICIAN SHORTAGE: Strategies for producing, recruiting and retaining primary care providers within a medically underserved region

Examines the inadequate supply of doctors in outlying regions of the Commonwealth. Through literature review, data analysis, personal interviews and other research methods, the UK Center for Excellence in Rural Health-Hazard study concluded that Kentucky needs an additional 600 primary care physicians in order to adequately meet the health care needs of its residents. The findings appear in the October 2005 Journal of the Kentucky Medical Association

The 1/N expansion of colored tensor models

In this paper we perform the 1/N expansion of the colored three dimensional Boulatov tensor model. As in matrix models, we obtain a systematic topological expansion, with more and more complicated topologies suppressed by higher and higher powers of N. We compute the first orders of the expansion and prove that only graphs corresponding to three spheres S^3 contribute to the leading order in the large N limit.Comment: typos corrected, references update

Ghost Kinetic Operator of Vacuum String Field Theory

Using the data of eigenvalues and eigenvectors of Neumann matrices in the 3-string vertex, we prove analytically that the ghost kinetic operator of vacuum string field theory obtained by Hata and Kawano is equal to the ghost operator inserted at the open string midpoint. We also comment on the values of determinants appearing in the norm of sliver state.Comment: 19 pages, 1 figure, lanlmac; v2: typos correcte