Learning Cognitive Therapy

A PRACTICAL GUIDE TO COGNITIVE THERAPY Dean Schuyler, M.D. W.W. Norton, 1991 $22.95 153 page

DESIGN FOR THE EXPERIMENTER

Three research problems, for which there was no obvious textbook design available, are presented. Each of the three involve constructing incomplete block designs for factorial treatment arrangements. While the designs are not likely optimal by any of the classical criteria, they meet the objectives of the research projects. The constructions involved confounding, with incomplete blocks, those effects which were of least interest. However, effects of interest were also allowed to be slightly non-orthogonal to blocks in order to be able to examine a larger number of effects of interest

Polaronic Signatures in Mid-Infrared Spectra: Prediction for LaMnO3 and CaMnO3

Hole-doped LaMnO3 and electron-doped CaMnO3 form self-trapped electronic states. The spectra of these states have been calculated using a two orbital (Mn eg Jahn-Teller) model, from which the non-adiabatic optical conductivity spectra are obtained. In both cases the optical spectrum contains weight in the gap region, whose observation will indicate the self-trapped nature of the carrier states. The predicted spectra are proportional to the concentration of the doped carriers in the dilute regime, with coefficients calculated with no further model parameters.Comment: 6 pages with 3 figures imbedde

THE ANALYSIS OF TREE RING CHRONOLOGIES USING A MIXED LINEAR MODEL

The analysis of a tree\u27s annual growth rings can provide a great deal of information about the environment in which the tree has grown. In this paper we propose statistical methodology for analysing the incremental growth of sugar maple sampled throughout southern and central Ontario, by the Ontario Ministry of the Environment. Two trees, ranging in age from 75 to 150 years, were sampled from each of 42 stands in 6 regions. The data were analysed using a mixed linear model, incorporating age of tree, region, year, a year by region interaction and average monthly air temperature and total seasonal precipitation for the current year and the previous year, as fixed effects. Stand and tree were regarded as random effects and the repeated annual growth measurements on a tree were assumed to follow a first order autoregressive process

Multi-level automated sub-zoning of water distribution systems

Water distribution systems (WDS) are complex pipe networks with looped and branching topologies that often comprise of thousands of links and nodes. This work presents a generic framework for improved analysis and management of WDS by partitioning the system into smaller (almost) independent sub-systems with balanced loads and minimal number of interconnections. This paper compares the performance of three classes of unsupervised learning algorithms from graph theory for practical sub-zoning of WDS: (1) Graph clustering – a bottom-up algorithm for clustering n objects with respect to a similarity function, (2) Community structure – a bottom-up algorithm based on network modularity property, which is a measure of the quality of network partition to clusters versus randomly generated graph with respect to the same nodal degree, and (3) Graph partitioning – a flat partitioning algorithm for dividing a network with n nodes into k clusters, such that the total weight of edges crossing between clusters is minimized and the loads of all the clusters are balanced. The algorithms are adapted to WDS to provide a decision support tool for water utilities. The proposed methods are applied and results are demonstrated for a large-scale water distribution system serving heavily populated areas in Singapore

Interaction between lateral sorting in river bends and vertical sorting in dunes

Sediment is sorted in river bends under the influence of gravity that pulls the heavier grains downslope and secondary flow that drags the finer grains upslope. Furthermore, when dunes are present, sediment is also sorted vertically at the dune lee side. However, sorting functions are poorly defined, since the relation to transverse bed slope and the interaction between lateral and vertical sorting is not yet understood for lack of data under controlled conditions. The objective of this study is to describe lateral sorting as a function of transverse bed slope and to gain an understanding of the interaction between lateral and vertical sorting in river bends. To this end, experiments were conducted with a poorly sorted sediment mixture in a rotating annular flume in which secondary flow intensity can be controlled separately from the main flow velocity, and therefore transverse bed slope towards the inner bend and dune dimensions can be systematically varied. Sediment samples were taken along cross‐sections at the surface of dune troughs and dune crests, and over the entire depth at the location of dune crests (bulk samples), which enabled comparison of the relative contribution of vertical sorting by dunes to lateral sorting by the transverse bed slope. The data show that lateral sorting is always the dominant sorting mechanism in bends, and bulk samples showed minor effects of vertical sorting by dunes as long as all grain‐size fractions are mobile. An empirical bend sorting model was fitted that redistributes the available sediment fractions over the cross‐section as a function of transverse bed slope. Comparison with field data showed that the model accurately reproduces spatially‐averaged trends in sorting at the bend apex in single‐thread channels. The bend sorting model therefore provides a better definition of bend sorting with conservation of mass by size fraction and adds to current understanding of bend sorting. The implication for numerical modelling is that bend sorting mechanisms can be modelled independently of dunes, allowing the application of the active layer concept

Temperature Dependence of Low-Lying Electronic Excitations of LaMnO_3

We report on the optical properties of undoped single crystal LaMnO_3, the parent compound of the colossal magneto-resistive manganites. Near-Normal incidence reflectance measurements are reported in the frequency range of 20-50,000 cm-1 and in the temperature range 10-300 K. The optical conductivity, s_1(w), is derived by performing a Kramers-Kronig analysis of the reflectance data. The far-infrared spectrum of s_1(w) displays the infrared active optical phonons. We observe a shift of several of the phonon to high frequencies as the temperature is lowered through the Neel temperature of the sample (T_N = 137 K). The high-frequency s_1(w) is characterized by the onset of absorption near 1.5 eV. This energy has been identified as the threshold for optical transitions across the Jahn-Teller split e_g levels. The spectral weight of this feature increases in the low-temperature state. This implies a transfer of spectral weight from the UV to the visible associated with the paramagnetic to antiferromagnetic state. We discuss the results in terms of the double exchange processes that affect the optical processes in this magnetic material.Comment: 7 pages, 5 figure