Runge Kutta Type Methods for Isodynamical Matrix Flows: Applications to Balanced Realizations

Recently several numerical methods have been proposed for solving isospectral problems which are matrix differential systems whose solutions preserve the spectrum during the evolution. In this paper we consider matrix differential systems called isodynamical flows in which only a component of the matrix solution preserves the eigenvalues during the evolution and we propose procedures for their numerical solution. Applications of such numerical procedures may be found in systems theory, in particular in balancing realization problems. Several numerical tests will be reported. Received April 27, 2001; revised October 25, 2001 Published online February 18, 2002     

Substructuring in linear and nonlinear analysis

The procedures for utilizing substructuring and static condensation in structural analysis are well known. However, until recently there have been no general-purpose structural mechanics computer systems that offer multi-level substructuring combined with a convenient method for defining the structural model. Now that such systems are available, engineers must decide when substructuring techniques are useful. Substructuring, with and without condensation, has proved to be highly efficient in the analysis of certain classes of structure. It can reduce computer costs by a factor of from 2 to 100. Yet, indiscriminate use of condensation may result in unnecessary and expensive computations. This paper examines the advantages and disadvantages of substructuring relative to data entry and computational efficiency. Guidelines are proposed for engineers to follow when using substructuring in the analysis of linear and nonlinear structures. The FINITE system is used to illustrate actual implementation of substructuring features in a general purpose finite element system.     

Influence of Mn on dielectric and piezoelectric properties of A-site and B-site modified PLZT nano-ceramics for sensor and actuator applications

[Pb_0.961La_0.012Ba_0.015Sr_0.012][Zr_0.53Ti_0.47]_0.967-(h/2)Nb_0.02Zn_0.01Mn_hO₃ (PLBSZZMNT) nano-ceramics where h = 0, 0.5. 1 and 1.5 mol% fabricated through solid state reaction method has been investigated for phase formation, microstructure, density, dielectric and piezoelectric properties. X-ray diffraction studies indicated that all the samples exhibited a single-phase perovskite tetragonal structure which had strongly intensified due to the acceptor Mn content increment in the series. Our investigation with reference to isovalent (Ba²⁺ and Sr²⁺) on the A-site, pentavalent donor (Nb⁵⁺) and acceptor (Zn²⁺ and Mn⁴⁺) dopants on the B-site in PLZT perovskite with the stoichiometric compositional formulation tailored for dielectric and piezoelectric properties has been clearly explained. As Mn concentration increased, the grain growth enhanced, and the inter-diffusion between multiple ions promoted densification in the PLBSZZMNT nano-ceramics. TEM studies revealed an average particle size ranging from 20 to 72 nm. Dielectric characterization revealed that the ε_RT enhanced till 1.5 mol% Mn (2946) while the Curie temperature and dielectric loss at room temperature (T_c and Tanδ_RT) decreased, respectively. Mn doping in PLBSZZNT induced the piezoelectric parameters (k_p = 0.567) and (d₃₃ = 486 pC/N) till 1.5 mol% Mn. Thus, 1.5 mol% Mn modified PLBSZZNT exhibits optimum dielectric and piezoelectric properties, which are suitable for possible sensor and actuator applications.     

Adult attachment orientations, self–other boundary regulation, and splitting tendencies in a college sample.

In a sample of 247 college students, the contributions of adult attachment orientations and several other boundary regulation variables to measures of self-splitting (i.e., the tendency to report diffuse and chaotic self-experiences) and other-splitting (i.e., the tendency to acknowledge unstable perceptions of and feelings toward one's friends) were explored. Adult attachment orientations and self-other boundary regulation variables, respectively, explained unique variance in each criterion measure. High levels of attachment anxiety and self-concealment and low levels of self-other differentiation contributed most prominently to self-splitting, whereas high attachment anxiety, low emotional reactivity, and high needs for social approval best predicted other-splitting. Implications of these findings for advancing a more delineated understanding of splitting tendencies are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The discovery of hidden facial images in the paintings of Vincent Van Gogh and Paul Gauguin by using computer graphics enhancement techniques

For nine short weeks in 1888, Vincent Van Gogh and Paul Gauguin lived and worked together in the city of Arles. Using computer graphics enhancement analyses, some of the paintings they did during this period revealed hidden facial images. One full hidden figure in a painting by Van Gogh and five camouflaged facial images in the works of Paul Gauguin were uncovered using computer graphics techniques. With the exception of one painting by Gauguin, these concealed images have not been previously reported.     

Internal auditory artery infarction: clinicopathologic correlation

Immunocytochemical examination for mitochondrial protein and cytochrome oxidase was performed to demonstrate oncocytes in normal adenohypophysis obtained from 28 patients of various age. A small number of solitary large epithelial cells showed intense cytoplasmic granular immunoreactivities for mitochondrial protein and cytochrome oxidase. The proportions of the cells positive for the former and the latter ranged from 0% to 5.9% (mean+/-SD; 1.5+/-1.7%) and from 0% to 4.9% (1.4+/-1.6%), respectively. These cells were either absent or extremely rare in young patients (under 10 years) but tended to increase in number with age (P < 0.0001). On the other hand, the mirror section technique showed that most of these cells were negative for adenohypophysial hormones, but a few of them were faintly positive for: alpha-subunit (8.0%), beta-subunits of follicle-stimulating hormone (4.8%), luteinizing hormone (2.5%), thyroid-stimulating hormone (1.0%), and growth hormone (0.5%), and were negative for prolactin and adrenocorticotropic hormone. We considered that these cells represent oncocytes that exist in varying numbers in normal adenohypophysis. It was suggested that oncocytes in normal adenohypophysis share various common features with tumorous oncocytes of pituitary oncocytomas.     

Ethnicity and psychopathology: A meta-analytic review of 31 years of comparative MMPI/MMPI-2 research.

Meta-analyses were performed on 25 comparative Minnesota Multiphasic Personality Inventory (MMPI) and MMPI-2 studies of 1,428 male African Americans versus 2,837 male European Americans, 12 studies of 1,053 female African Americans versus 1,470 female European Americans, and 13 studies of 500 male Latino Americans and 1,345 male European Americans. Aggregate effect sizes suggest higher scores for ethnic minority groups than for European Americans on some MMPI/MMPI-2 scales and lower scores on others. However, none of the aggregate effect sizes suggest substantive differences from either a statistical or clinical perspective. The MMPI and MMPI-2 apparently do not unfairly portray African Americans and Latinos as pathological. Effect sizes across studies generally did not vary as a function of sociodemographic variables, research setting, or use of the MMPI versus MMPI-2. It is recommended that additional between- and within-ethnic groups psychopathology research continue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis and experimental results of a single-stagehigh-power-factor electronic ballast based on flyback converter

A new single-stage high-power-factor electronic ballast based on a flyback converter is presented in this paper. The ballast is able to supply a fluorescent lamp assuring a high-input power factor for the utility line. Other features are lamp power regulation against line voltage variations and low lamp current crest factor, both assuring long lamp life. The ballast is analyzed at steady-state operation, and design equations and characteristics are obtained. Also, a procedure for the ballast design is presented. Finally, simulation and experimental results from a laboratory prototype are shown     

Dynamic processes underlying adult attachment organization: Toward an attachment theoretical perspective on the healthy and effective self.

Contemporary attachment theory is inspiring a burgeoning literature on adult attachment. This literature offers counseling psychology a compelling framework for understanding the healthy and effective self. In this article, the authors review studies probing the cognitive processes, affect self-regulatory dynamics, and relationship behaviors associated with secure (primary) and insecure (secondary) adult attachment strategies. They then offer a portrait of the healthy, effective personality that is consistent with theory and research on adult attachment. Finally, in an effort to understand key characteristics of successful movement toward the healthy and effective self, the authors review empirical extensions of attachment theory to the therapeutic context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)