Robustness of sequential gamma life-testing procedures in respect of expected failure times

Sequential life-testing procedures assuming a gamma lifetime distribution may be used even when the shape parameter, representing the intensity of increasing or decreasing failure rate, has changed. Prompted by such mis-specifications, the present paper investigates the robustness of these procedures in respect of expected number of failures before a decision is reached. In the light of the non-robust character of these procedures, an economic trade-off between the risks and the expected number of failures can be performed to amend suitably the values of preassigned risks.     

A Simple CMOS-Based Membership Function Circuit

In this study, design and analysis of a voltage-input current-output simple CMOS-based Membership Function Circuit (MFC) is presented. The proposed MFC is based on simple OTA structure and current-mode maximum circuits. This MFC implements basic four membership functions (trapezoidal, triangle, Z-shape and S-shape). The characteristics (width, height, slope and position) of the implemented membership functions are easily adjustable and it is suitable for current-mode fuzzy hardware. While the circuit's membership function characteristics have been confirmed by PSPICE-DC simulations, the circuit's transient response has been analyzed applying up to 10 MHz input signals in continuous time by PSPICE Transient simulations.     

A finite element Laplace transform solution technique for the wave equation

A technique is described for the solution of the wave equation with time dependent boundary conditions. The finite element solution accompanied by the numerical Laplace inversion process seems to be an efficient procedure to treat such problems. The programming involved is straightforward in the sense that numerical Laplace inversion routines can be directly used as a time integration procedure after obtaining standard finite element differential equation solutions in the transformed domain. Some results are presented for one- and two- dimensional applications, such as wave propagation in longitudinal bars and wave propagation in harbours.     

Attitudes of Kuwaiti parents toward physical punishment of children

OBJECTIVE: The major aim was to describe parental attitudes to physical punishments and examine their sociodemographic correlates. A related aim was to assess the association of parents' own experience of physical punishment with attitudes to punishment of children. METHOD: A cross-sectional survey was conducted during the second week of December, 1996 in five general clinics covering the major administrative areas of Kuwait: 337 Kuwaiti mothers and fathers with at least one living child were contacted; 95% were successfully interviewed using a structured questionnaire. RESULTS: Eighty-six percent of parents agreed with physical punishment as a means of child disciplining. Agreement with punishment was higher in case of serious misbehaviors such as stealing (63%), sniffing glue and using drugs (77%). Multiple regression results showed that parent's lower level of education and Bedouin ethnicity were positively associated with agreement on physical punishment. Larger percentages of parents who had experienced physical punishments themselves agreed with such punishment to discipline their children, but this was not statistically significant. CONCLUSIONS: In recent years education has become widespread for both sexes. An inverse association between educational level and agreement on physical beating suggest that attitudes to this form of child disciplining are changing. Those with a Bedouin ethnic background still adhere more strictly to the traditional forms of child disciplining including physical beating. There is a need for conducting research on the possible negative psychosocial impacts of physical punishment in view of findings from other countries.     

Reducing Effective Liquid Wall Thickness in a HYLIFE-II Fusion Breeder

One of the major inertial fusion energy reactor designs is HYLIFE-II which uses protective flowing liquid wall between fusion plasma and solid first wall. The most attractive aspect of this reactor is that protective liquid wall eliminates the frequent replacement of the first wall structure during reactor lifetime. Liquid wall thickness must be at least the thickness required for supplying sufficient tritium for the deuterium–tritium (DT) driver and satisfying radiation damage on the first wall below the limits. Reducing this thickness results less pumping power requirements and cost of electricity. In this study, investigation on potential of utilizing refractory alloys (W-5Re, TZM and Nb-1Zr) as first wall to reduce effective liquid wall thickness in HYLIFE-II reactor using liquid wall of Flibe + 10 mol % UF₄ mixture. Neutron transport calculations were carried out with the help of the SCALE4.3 system by solving the Boltzmann transport equation with the XSDRNPM code in 238 neutron groups and a S₈-P₃ approximation. Numerical results showed that using W-5Re or TZM as first wall was effective in decreasing liquid wall thickness in contrast to Nb-1Zr.     

Pathological examination of sentinel lymph node in breast cancer: potential problems and possible solutions

Sentinel lymph node (SLN) biopsy has emerged during the last few years as a viable option for staging the axilla in the treatment of breast carcinoma. This procedure can potentially identify patients who would be helped by full axillary lymph node dissection (the SLN-positive cases), and those who would not (the SLN-negative cases). Review of the literature confirms the promise of SLN; however, the possible problems in the pathological handling of SLN, including the microscopic misinterpretation of benign structures and "spurious" immunohistochemical staining, need wider recognition.     

Editorial: Open Source and Empirical Software Engineering

Editorial Commentary

Editorial: Open Source and Empirical Software Engineering