Some identities on derangement and degenerate derangement polynomials

In combinatorics, a derangement is a permutation that has no fixed points. The number of derangements of an n-element set is called the n-th derangement number. In this paper, as natural companions to derangement numbers and degenerate versions of the companions we introduce derangement polynomials and degenerate derangement polynomials. We give some of their properties, recurrence relations and identities for those polynomials which are related to some special numbers and polynomials.Comment: 12 page

Quantum-disordered slave-boson theory of underdoped cuprates

We study the stability of the spin gap phase in the U(1) slave-boson theory of the t-J model in connection to the underdoped cuprates. We approach the spin gap phase from the superconducting state and consider the quantum phase transition of the slave-bosons at zero temperature by introducing vortices in the boson superfluid. At finite temperatures, the properties of the bosons are different from those of the strange metal phase and lead to modified gauge field fluctuations. As a result, the spin gap phase can be stabilized in the quantum critical and quantum disordered regime of the boson system. We also show that the regime of quantum disordered bosons with the paired fermions can be regarded as the strong coupling version of the recently proposed nodal liquid theory.Comment: 5 pages, Replaced by the published versio

alpha_s From the Lattice and Hadronic Tau Decays

Until recently, determinations of alpha_s(M_Z) from hadronic tau decays and the analysis of short-distance-sensitive lattice observables yielded results which, though precise, were not in good agreement. I review new analyses that bring these into good agreement and provide some details on the source of the main changes in the tau decay analysis.Comment: 4 pages, prepared for the proceedings of CIPANP 09, San Diego, USA, March 26-31, 200

Bayesian matching of unlabelled point sets using Procrustes and configuration models

The problem of matching unlabelled point sets using Bayesian inference is considered. Two recently proposed models for the likelihood are compared, based on the Procrustes size-and-shape and the full configuration. Bayesian inference is carried out for matching point sets using Markov chain Monte Carlo simulation. An improvement to the existing Procrustes algorithm is proposed which improves convergence rates, using occasional large jumps in the burn-in period. The Procrustes and configuration methods are compared in a simulation study and using real data, where it is of interest to estimate the strengths of matches between protein binding sites. The performance of both methods is generally quite similar, and a connection between the two models is made using a Laplace approximation

Towards Language-Universal End-to-End Speech Recognition

Building speech recognizers in multiple languages typically involves replicating a monolingual training recipe for each language, or utilizing a multi-task learning approach where models for different languages have separate output labels but share some internal parameters. In this work, we exploit recent progress in end-to-end speech recognition to create a single multilingual speech recognition system capable of recognizing any of the languages seen in training. To do so, we propose the use of a universal character set that is shared among all languages. We also create a language-specific gating mechanism within the network that can modulate the network's internal representations in a language-specific way. We evaluate our proposed approach on the Microsoft Cortana task across three languages and show that our system outperforms both the individual monolingual systems and systems built with a multi-task learning approach. We also show that this model can be used to initialize a monolingual speech recognizer, and can be used to create a bilingual model for use in code-switching scenarios.Comment: submitted to ICASSP 201

Effects of kelp canopy removal on young-of-the-year rockfish abundance, using two census methods

In 1976 an experimental research project was initiated to examine the possible effects of the removal of a giant kelp, Macrocystis pyrifera, canopy in a central California kelp bed on Young-of-the-Year (YOY) fish populations. A total of 7823 fishes was captured and marked using freeze branding. Pre-canopy removal population estimates were made using the Schnabel method and post-canopy removal population estimates were made using the Petersen method (Lincoln Index). A significant (p < .0004) reduction of fish occurred immediately after the canopy was removed and the population remained at a reduced level for at least 60 days. This information warranted the creation of a second expanded project. In 1977 we established three study areas consisting of a kelp bed to be harvested (C), a kelp bed not to be harvested (NC) and a control kelp bed. We captured and marked over 82,000 YOY fish in Areas C and NC. Using the same statistical methods from the 1976 study, a significant reduction was found to occur in fish populations within harvested Area C and unharvested area NC: however, the reductions were not significantly different between the two areas. The large reduction in the fish population in the harvested area occurred when fish moved into the unharvested area. The large, unexpected reduction in fish numbers in the unharvested area (NC) occurred when larger predatory YOY bocaccio moved into the control area (X) as the experimental area (C) was being harvested. The bocaccio removed in excess of 20% of the biomass of YOY blue rockfish, which was composed of resident fish and recently migrated fish from the harvested kelp bed. Predation on YOY blue rockfish was also evident in the harvested area. Population estimates using visible fish transects by divers correlated well with population estimates from the capture/recapture studies in 1976, but correlation was poorer the following year when many more fish were present. (32pp.