The supervised hierarchical Dirichlet process

We propose the supervised hierarchical Dirichlet process (sHDP), a nonparametric generative model for the joint distribution of a group of observations and a response variable directly associated with that whole group. We compare the sHDP with another leading method for regression on grouped data, the supervised latent Dirichlet allocation (sLDA) model. We evaluate our method on two real-world classification problems and two real-world regression problems. Bayesian nonparametric regression models based on the Dirichlet process, such as the Dirichlet process-generalised linear models (DP-GLM) have previously been explored; these models allow flexibility in modelling nonlinear relationships. However, until now, Hierarchical Dirichlet Process (HDP) mixtures have not seen significant use in supervised problems with grouped data since a straightforward application of the HDP on the grouped data results in learnt clusters that are not predictive of the responses. The sHDP solves this problem by allowing for clusters to be learnt jointly from the group structure and from the label assigned to each group.Comment: 14 page

Zenithal bistable device: comparison of modeling and experiment

A comparative modeling and experimental study of the zenithal bistable liquid crystal device is presented. A dynamic Landau de Gennes theory of nematic liquid crystals is solved numerically to model the electric field induced latching of the device and the results are compared with experimental measurements and theoretical approximations. The study gives a clear insight into the latching mechanism dynamics and enables the dependence of the device latching on both material parameters and surface shape to be determined. Analytical approximation highlights a route to optimize material selection in terms of latching voltages and the numerical model, which includes an accurate surface representation, recovers the complex surface shape effects. Predictions of device performance are presented as a function of both surface anchoring strength and surface shape and grating pitch. A measurement of the homeotropic anchoring energy has been undertaken by comparing the voltage response as a function of cell gap; we find the homeotropic anchoring energies can be varied in the range 0.5 to 4 (10-44 J m-2)

Efficiency Audit Guidelines (1993)

"Reviewed October 1, 1993."An efficiency audit allows a firm to systematically review its entire operation and to determine potential cost reductions. Areas for potential cost reduction include management, production, purchasing, marketing and finance. By thoroughly evaluating these areas, management can determine a realistic goal for total cost reduction. This goal may be to break even or to increase profits 10 percent more than last year. Those areas with the greatest potential for cost reduction should have the highest priority. After management establishes priorities, it will be able to develop an action plan to put the firm back on the road to higher profits

Entropy production for coarse-grained dynamics

Systems out of equilibrium exhibit a net production of entropy. We study the dynamics of a stochastic system represented by a Master Equation that can be modeled by a Fokker-Planck equation in a coarse-grained, mesoscopic description. We show that the corresponding coarse-grained entropy production contains information on microscopic currents that are not captured by the Fokker-Planck equation and thus cannot be deduced from it. We study a discrete-state and a continuous-state system, deriving in both the cases an analytical expression for the coarse-graining corrections to the entropy production. This result elucidates the limits in which there is no loss of information in passing from a Master Equation to a Fokker-Planck equation describing the same system. Our results are amenable of experimental verification, which could help to infer some information about the underlying microscopic processes

Break-Even Analysis for Management Decision-Making (1993)

"Reviewed October 1, 1993."Break-even analysis can help management decide among many financial alternatives. Several decisions are aided by break-even analysis, such as those relative to pricing and machinery or equipment purchasing

Managing Your Time (1993)

"Reviewed October 1, 1993."No one has enough time. Time is a unique resource as it cannot be accumulated like money or stock-piled like materials. We spend it at a fixed rate. Since all of us have exactly the same amount of time, the real problem is not how much we have, but how we use our time. How well it is used often determines the manager's success

Flory theory for Polymers

We review various simple analytical theories for homopolymers within a unified framework. The common guideline of our approach is the Flory theory, and its various avatars, with the attempt of being reasonably self-contained. We expect this review to be useful as an introduction to the topic at the graduate students level.Comment: Topical review appeared J. Phys.: Condens. Matter, 46 pages, 8 Figures. Sec. VIF added. Typos fixed. Few references adde

Determination of the forward slope in p pp~p and pˉ p\bar p~p elastic scattering up to LHC energy

In the analysis of experimental data on $p p$ (or $\bar p p$) elastic differential cross section it is customary to define an average forward slope $b$ in the form $\exp{(-b|t|)}$, where $t$ is the momentum transfer. Taking as working example the results of experiments at Tevatron and SPS, we will show with the help of the impact picture approach, that this simplifying assumption hides interesting information on the complex non-flip scattering amplitude, and that the slope $b$ is not a constant. We investigate the variation of this slope parameter, including a model-independent way to extract this information from an accurate measurement of the elastic differential cross section. An extension of our results to the LHC energy domain is presented in view of future experiments.Comment: 12 pages, 6 figures, to appear in EPJ