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Stress Problems (stress + problem)
Selected AbstractsChild Behavior Checklist Juvenile Bipolar Disorder (CBCL-JBD) and CBCL Posttraumatic Stress Problems (CBCL-PTSP) scales are measures of a single dysregulatory syndromeTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 10 2009Lynsay Ayer Background:, The Child Behavior Checklist Juvenile Bipolar Disorder (CBCL-JBD) profile and Posttraumatic Stress Problems (CBCL-PTSP) scale have been used to assess juvenile bipolar disorder (JBD) and posttraumatic stress disorder (PTSD), respectively. However, their validity is questionable according to previous research. Both measures are associated with severe psychopathology often encompassing multiple DSM-IV diagnoses. Further, children who score highly on one of these scales often have elevated scores on the other, independent of PTSD or JBD diagnoses. We hypothesized that the two scales may be indicators of a single syndrome related to dysregulated mood, attention, and behavior. We aimed to describe and identify the overlap between the CBCL-JBD profile and CBCL-PTSP scales. Method:, Two thousand and twenty-nine (2029) children from a nationally representative sample (1073 boys, 956 girls; mean age = 11.98; age range = 6,18) were rated on emotional and behavior problems by their parents using the CBCL. Comparative model testing via structural equation modeling was conducted to determine whether the CBCL-JBD profile and CBCL-PTSP scale are best described as measuring separate versus unitary constructs. Associations with suicidality and competency scores were also examined. Results:, The CBCL-JBD and CBCL-PTSP demonstrated a high degree of overlap (r = .89) at the latent variable level. The best fitting, most parsimonious model was one in which the CBCL-JBD and CBCL-PTSP items identified a single latent construct, which was associated with higher parental endorsement of child suicidal behavior, and lower functioning. Conclusions:, The CBCL-JBD profile and CBCL-PTSP scale overlap to a remarkable degree, and may be best described as measures of a single syndrome. This syndrome appears to be related to severe psychopathology, but may not conform to traditional DSM-IV classification. These results contribute to the ongoing debate about the utility of the CBCL-JBD and CBCL-PTSP profiles, and offer promising methods of empirically based measurement of disordered self-regulation in youth. [source] Numerical modeling of creep and creep damage in thin plates of arbitrary shape from materials with different behavior in tension and compression under plane stress conditionsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 11 2009A. Zolochevsky Abstract A constitutive model for describing the creep and creep damage in initially isotropic materials with characteristics dependent on the loading type, such as tension, compression and shear, has been applied to the numerical modeling of creep deformation and creep damage growth in thin plates under plane stress conditions. The variational approach of establishing the basic equations of the plane stress problem under consideration has been introduced. For the solution of two-dimensional creep problems, the fourth-order Runge,Kutta,Merson's method of time integration, combined with the Ritz method and R-functions theory, has been used. Numerical solutions to various problems have been obtained, and the processes of creep deformation and creep damage growth in thin plates of arbitrary shape have been investigated. The influence of tension,compression asymmetry on the stress,strain state and damage evolution, with time, in thin plates of arbitrary shape, has been discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] Digital simulation of the transformation of plane stressCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2009Wei-Pin Lee Abstract In this study, we developed a computer program to simulate the transformation of plane stress by using Visual Basic.NET. We applied the equations of stress transformation to plane stress problems to calculate the stresses with respect to the 1,2 axes, which are rotated counterclockwise through an angle , about the x,y origin, and showed the visual results on the screen. In addition, we used animation to observe the change of plane stress. This program was then used in teaching courses, such as Mechanics of Materials and Linear Algebra. Use of the software may help students to understand principal stresses, principal axes, Mohr's circle, eigenvalues, eigenvectors, similar matrices, and invariants. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 17: 25,33, 2009; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20180 [source] Optimum shapes of tire-treads for avoiding lateral slippage between tires and roadsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2005S. Reaz Ahmed Abstract Optimum design of tire-tread sections is an important practical issue. However, useful study of the problem that can suggest a reliable guideline for determining the optimum tread sections had hardly been made in the past. The present paper describes a new analysis of the state of stresses in tire-tread sections in contact with the road surface, taking special care of the boundary conditions. Based on the analysis, a method is proposed to determine the optimum tread shapes for avoiding lateral slippage between tires and roads. The displacement potential function formulation, an ideal mathematical model for the practical stress problems, has been used in conjunction with finite-difference method of solution. For the present analysis, lateral slipping in absence of frictional resistance as well as the no-slip conditions of the tire-tread contact surface have been considered along with a large number of tread aspect ratios. The present computational approach proves to be a powerful tool for determining the optimum tread shapes for avoiding the lateral slippage of tire-treads. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||