Showing papers by "University of Windsor published in 1984"

K-Means-Type Algorithms: A Generalized Convergence Theorem and Characterization of Local Optimality

Abstract: The K-means algorithm is a commonly used technique in cluster analysis. In this paper, several questions about the algorithm are addressed. The clustering problem is first cast as a nonconvex mathematical program. Then, a rigorous proof of the finite convergence of the K-means-type algorithm is given for any metric. It is shown that under certain conditions the algorithm may fail to converge to a local minimum, and that it converges under differentiability conditions to a Kuhn-Tucker point. Finally, a method for obtaining a local-minimum solution is given.

Homosexual identity formation as a developmental process.

Abstract: Homosexual identity is conceptualized as a life-spanning developmental process that eventually leads to personal acceptance of a positive gay self-image and a coherent personal identity. HabermasAE theory of ego development is utilized to provide a synthesis and understanding of the literature on the construction and maintained of the homosexual identity. It is concluded that the homosexual identity generally emerges in a three-stage process in which the person progresses form: (1) an egocentric interpretation of homoerotic feelings to (2) an internalization of the normative, conventional assumptions about homosexuality to (3) a post-conventional phase in which societal norms are critically evaluated and the positive gay identity is achieved and managed. Developmental task associated with each stage are outlined in terms of their ego-integrative factions. Although the stages in the process of homosexual identity formation are theoretically the same for females and male, because of the paucity of research o...

Partisan Instability in Canada: Evidence from a New Panel Study

Abstract: One of the critical questions in the debate about the concept of party identification is its stability over time, particularly its stability relative to that of voting behavior. This article utilizes data from a new three-wave panel study to assess the properties of party identification in Canada, and to compare levels of partisan stability in Canada with those in Great Britain and the United States. In addition to directional stability, other features of the party identification concept and its applicability to Canada are examined, notably the constituency of identification across levels of the federal system. Analyses indicate that party identification in Canada is subject to considerable fluctuation, and that the U.S. pattern of relatively stable party identification coupled with substantial short-term swings in voting behavior reflect the institutional characteristics of the U. S. electoral system. The article concludes by suggesting that patterns of partisanship in Canada, although distinctive in certain respects, probably have important commonalities with those in many other contemporary liberal democracies.

Frost weathering and the saturation of coastal rocks

Abstract: Measurements were made of the water content in coastal rocks, by simulating tidal oscillations in the laboratory, and by field measurement in eastern Canada. If rapid freezing takes place upon exposure to the air, saturation levels may be high enough to permit frost weathering in fine grained rocks in the lower portions of the intertidal zone. Near the high tidal level, however, it may be dependent upon a supply of water from the ice foot and from melting snow. If freezing is slow, frost action may be inhibited by desorption of the rocks while they are exposed by the ebb tide. There was no evidence of a level of permanent sea water saturation within the intertidal zone. Ambient temperature and humidity may affect the rate of rock desorption.

Certain inverse solutions of a non-Newtonian fluid

Abstract: Solutions for the equations of motion of an incompressible second grade fluid are obtained by employing semi-inverse methods in which we assume certain geometrical or kinematical properties of the fields. Specifically the problems studied in viscous fluids by Jeffery, Hamel and Gortler and Wieghardt, etc. are considered in a second grade fluid and the results for stream lines, velocities and pressure distribution are compared in the two cases.

Effect of Temperature on Consecutive Denitrification Reactions in Brookston Clay and Fox Sandy Loam

Abstract: The kinetics of several steps in the microbial denitrification process in Brookston clay and Fox sandy loam, two soils common to Southwestern Ontario, were studied in the temperature range of 5 to 25°C. The extent of chemical denitrification was also determined in otherwise identical but sterilized soils at temperatures up to 80°C. A gas flow system was used in which soil gases were continuously removed from anaerobic soil columns by argon carrier gas. Net steady-state rates of NO and N2O production, rates of loss of NO3−, and production and loss of NO2− were measured over periods of up to 5 days. Arrhenius activation energies for the zero-order process NO3− → NO2− were calculated to be 50 ± 9 kJ mol−1 for Brookston clay and 55 ± 13 kJ mol−1 for Fox sandy loam. The overall reaction, NO2− → NO (chemodenitrification), in both sterile soils was accurately first order with respect to NO2−; the activation energy was 70 ± 2.8 kJ mol−1 in Brookston clay and 79 ± 1.2 kJ mol−1 in the sandy loam, and the preexponential factors were (2.3 ± 1.2) × 109 and (5.7 ± 1.2) × 109 min−1, respectively.

Genetic differentiation among populations of marine algae

Abstract: Most of the information for genetic differentiation among populations of marine algae is from studies on ecotypic variation. Physiological ecotypes have been described for individuals showing different responses to temperature and salinity conditions. Morphological ecotypes have also been found associated with areas differing in wave exposure or different intertidal positions. Little is known on how genetic variation is organized within and between populations of marine algae. The occurrence of ecotypic variation in some species is evidence for genetic differentiation among populations resulting from selection by the local environment. The rate of dispersal and subsequent gene flow will also affect the level of differentiation among populations. In species with low dispersal, differentiation can arise through chance founder events or random genetic drift. The few studies available have shown that species of algae exhibit a range of dispersal capabilities. This information can be useful for predicting the potential level of genetic differentiation among populations of these species. Crossing experiments with several species of algae have shown that populations separated by a considerable distance can be interfertile. In some cases individuals from these populations have been found to be morphologically distinct. Crosses have been used to study the genetic basis of this variation and are evidence for genetic differentiation among the populations sampled. Genetic variation of enzyme proteins detected by electrophoresis provides an additional method for measuring genetic variation within and between populations of marine algae. Electrophoretic methods have previously been used to study systematic problems in algae. However, there have been few attempts to use electrophoretic variation to study the genetic structure of populations of marine algae. This approach is outlined and includes some of the potential problems associated with interpreting electrophoretic data. Studies of electrophoretic variation in natural populations ofEnteromorpha linza from Long island Sound are used as an example. This species was found to reproduce only asexually. Despite a dispersing spore stage, genetic differentiation was found on a microgeographic scale and was correlated with differences in the local environment of some of the populations. Similar studies on other species, and especially sexually reproducing species, will add to a growing understanding of the evolutionary genetics of marine algae.

Dipole and non-dipole excitation in collisions of low energy electrons with diatomic molecules

Abstract: The authors have measured the rotational envelopes of selected vibrational bands of H2, D2, N2 and CO following excitation of cooled ( approximately 25K) gas beams. The observed broadening in N2 and CO at low impact energies is attributed to a breakdown of the electric dipole rotational selection rule mod Delta J mod =1. No broadening is observed in H2 or D2.

Maximum likelihood estimation for the generalized poisson distribution

Abstract: The generalized Poisson distribution;containing two parameters and studied by many researchers; describes the distribution of busy periods under a queueing system and has very interesting properties; The probabilities for successive classes depend upon the previous occurrences; The problem of admissible maximum likelihood estimators for for the parameters Is discussed and a necessary and sufficient condition is derived for which unique admissible maximum likelihood estimators exist; The first; order terms in the biases; variances and the covariance of these maximum likelihood estimators are obtained.

When Two Wrongs Make a Right

Abstract: 1. When it applies. Today's topic is to learn about a method, " Separation of Variables " which can be used to solve differential equations of a certain special form. To use separation of variables, the equation must be of the type dy dx = (Some function of y) · (Some function of x). Here by " y " we really mean a function y(x) of x, but we are using the kind of notation where we don't include those helpful details. Here are some equations where you can apply separation of variables: (1) dy dx = − x y. This is of the correct form, since we can write − x y = (1 y) · (−x), which is of the form (a function of y) times (a function of x). (2) dy dx = x · y. This is also clearly of the correct form. The following differential equation is not of the right form: dy dx = y − x. It isn't of the form (a function of y) times (a function of x). You have to be a little careful when you're deciding however. For instance (3) dy dx = xy + x + y + 1. is an equation of the right form, since xy + x + y + 1 = (y + 1) · (x + 1).

Ionization and Attachment Coefficients in SF6 + N2 Mixtures

Abstract: Steady-state ionization growth currents have been measured in N2 and SF6 + N2 mixtures in the E/N range of 1.82×101-15 ? E/N ? 2.58×10-15 V cm2. Least-square analysis is used for the evaluation of apparent ionization, ionization, and attachment coefficients. Experimental E/N limits are observed for several SF6 concentrations in the mixture. The variation of (?-?)/N is non-linear with the percnetage mixture ratio.

Morphine Concentrations in Brain Tissue From Heroin-Associated Deaths

Abstract: The object of this study was to correlate blood morphine concentrations to regional brain concentrations and indirectly to opiate receptor density. Brain sections obtained postmortem from 21 suspected heroin-associated fatalities were analyzed for morphine by gas chromatography with FID. In all of the cases where death was attributed to narcotic overdose the concentration of morphine was found to exceed the minimum fatal concentration, 0.2/~g/g of tissue, in one or more of the brain sections, whereas the blood concentration exceeded 0.2/~g/g In only five cases. The correlation between the concentrations in the thalamus and blood were very good, suggesting that the thalamus could be used to estimate blood morphine concentration by the forensic toxicologist. Statistical analysis of the data Is presented. toxicology laboratory, the brain is of particular interest because of the high concentration of opiate receptors localized in the limbic system, primarily in the amygdala, corpus striatum and the hypothalamus (5-7). Opiate receptors are also concentrated in the central gray matter of the brain stem and the central part of the thalamus along the paleospinothalamic pathway. Since most of the opiate receptors are located in the brain and it is the site where most, if not all, of the effects of the drug originate, it is of interest to determine the concentration of morphine in various areas of the brain and relate it to the blood concentration. In this study a relatively simple and efficient extraction and derivatization procedure has been used for the preparation of bis(0-trimethylsilyl) morphine. The derivative is analyzed by gas chromatography using a 3% OV-17 column and a flame ionization detector. With the procedure as described the minimum sensitivity for detection of morphine was 0.07 #g per gram of brain tissue.

A Predictive Approach to Freud's Formulations Regarding Suicide

Abstract: This study of suicide notes involved the deduction of 25 protocol sentences that reflected important specific aspects of Freud's formulations regarding suicide. Independent judges noted the incidence of contents corresponding to the protocol sentences in 33 genuine and 33 simulated notes. Comparisons between genuine and simulated notes revealed that the protocol sentences discriminated significantly as a set in favor of the genuine notes. Individual statements found significantly more frequently in genuine notes indicated loss and/or rejection, preoccupation with a lost person, ambivalence toward a lost person, identification with a lost person, communicating feelings of anger toward oneself but appearing to be angry toward someone else, turning back upon oneself murderous wishes or impulses, and seeing the act as a fulfillment of self-punishment. A frequency count of the sentences in the notes indicated that these statements occurred quite frequently (i.e., at least one-third of the time) in the genuine notes. Implications of the results are discussed.

Optimal Electrode-Solid Insulator Geometry with Accumulated Surface Charges

Abstract: The electric field distribution along the interface of a solid insulator-vacuum (or gas) is analyzed for different solid insulator-electrode configurations with and without the presence of surface charges using the charge simulation technique. The tangential component of the electric field at the solid insulator-electrodevacuum (or gas) triple junction is found to be reduced in cases where the contact electrode extends into the solid insulator and where the solid insulator is placed in a recessed electrode. The reduction in the field increases with increasing the penetration length of the metal insert and the depth of the recess in the electrode. The results give a theoretical justification for the previously observed higher flashover values for insulators with metal inserts and for those placed in recessed electrodes.

Quantitative Approaches to the Neuropsychological Assessment of Children

Abstract: It would seem virtually axiomatic that the aim of psychological inquiry as it relates to the assessment of children is to produce a system for this purpose that is objective and consensually validatable. Whether such a system need be quantitative is a moot point. Certainly, there are many who would argue that a qualitative approach to assessment can be at least as objective and as open to consensual validation as are any quantitative approaches (e.g., Luria & Majovski, 1977).

A predictive approach to suicide notes of young and old people from Freud's formulations with regard to suicide.

Abstract: This study on suicide notes of young and old people involved the deduction of 25 protocol sentences that reflected important specific aspects of S. Freud's formulations with regard to suicide. Independent judges noted the incidence of contents that correspond to the protocol sentences in 52 notes. Comparisons between the suicide notes revealed that the protocol sentences discriminated significantly as a set in favor of the notes of young people. Specific sentences that were found more frequently in the notes of young people indicated being more self-critical, being more harsh toward oneself, perceiving oneself as having little worth, and treating oneself as an object. Implications are discussed. Language: en

Methods Of Calculations Of Field Stresses In A Three-Core Power Cable

Abstract: A numerical method using the charge simulation technique with only a small number of line charges is developed to calculate the electric field everywhere in a three-core high voltage, high power belted cable. Only six line charges are used of which three lines represent the three conductors and three image line charges to take account of the grounded sheath. The locations of the maximum electric stress in the cable are determined. Experimental measurements is also carried out using an electrolytic tank to verify the calculations. Good agreement is obtained. The results are presented in a normalized format so that they can readily be applied.

Play Up! Play Up! And Play the Game! Sport at the Late Victorian Girls' Public School

Abstract: Although in recent years Victorianists have eagerly cultivated the fields of sport and women's history, they have produced surprisingly little relating the two areas. Historians of women have virtually ignored the physical dimension of the struggle for female emancipation, while historians of sport have reflected sport's traditional male orientation by neglecting the distaff side. As W. J. Baker noted recently in the Journal of Sport History, “the history of British women in sports … stands high on the agenda of work to be done.”What limited material there is on women's sport history as such has tended to be produced by physical educators or amateurs like former players and journalists whose methodology can only be described as narrative-descriptive. A broad historical perspective permitting an exploration of the relationship between women's sport and social change is noticeable by its absence. Interpretation and analysis if they exist at all are usually limited to commonplace and uncritical observations about sport mirroring social attitudes to women and providing them with new opportunities for recreation and physical exercise. Such studies should not be denigrated, for when precious little has been known even of the facts of women's involvement in sport their revelation is certainly an important stage in the journey of discovery. However, if a truly meaningful and comprehensive picture is to be developed interpretative accounts are needed, which deal with such topics as power and control, motivation, the nature of participation, female sport's ambiguities and socially disruptive potential, its emancipating and restricting characteristics, and the interaction between feminism and female athleticism.

On the estimation of the intraclass correlation

Abstract: The problem of estimating the intraclass correlation when the sampling design is unbalanced is discussed. The method of moments is used to derive an approximation to the distribution of the estimate of the intraclass correlation obtained by the variance components approach. The maximum likelihood estimator is also presented, along with a simple procedure due to Richard (1961), for numerically maximizing a likelihood function of several parameters. Finally, the issue of optimal study design is considered for both balanced and unbalanced situations. For given power we determine the number of sets required to detect different values of the intraclass correlation.