Quality aspects for component‐based systems: A metrics based approach

In component‐based development, software systems are built by assembling components already developed and prepared for integration. To estimate the quality of components, complexity, reusability, dependability, and maintainability are the key aspects. The quality of an individual component influences the quality of the overall system. Therefore, there is a strong need to select the best quality component, both from functional and nonfunctional aspects. The present paper produces a critical analysis of metrics for various quality aspects for components and component‐based systems. These aspects include four main quality factors: complexity, dependency, reusability, and maintainability. A systematic study is applied to find as much literature as possible. A total of 49 papers were found suitable after a defined search criteria. The analysis provided in this paper has a different objective as we focused on efficiency and practical ability of the proposed approach in the selected papers. The various key attributes from these two are defined. Each paper is evaluated based on the various key parameters viz. metrics definition, implementation technique, validation, usability, data source, comparative analysis, practicability, and extendibility. The paper critically examines various quality aspects and their metrics for component‐based systems. In some papers, authors have also compared the results with other techniques. For characteristics like complexity and dependency, most of the proposed metrics are analytical. Soft computing and evolutionary approaches are either not being used or much less explored so far for these aspects, which may be the future concern for the researchers. In addition, hybrid approaches like neuro‐fuzzy, neuro‐genetic, etc., may also be examined for evaluation of these aspects. However, to conclude that one particular technique is better than others may not be appropriate. It may be true for one characteristic by considering different set of inputs and dataset but may not be true for the same with different inputs. The intension in the proposed work is to give a score for each metric proposed by the researchers based on the selected parameters, but certainly not to criticize any research contribution by authors. Copyright © 2012 John Wiley & Sons, Ltd.     

Fast and efficient extraction algorithm for high-speed interconnects with arbitrary boundaries

In this paper, we present an accurate and general interconnect model for planar transmission line interconnects with arbitrary boundary conditions. Based on the unified approach, we develop a SPICE-compatible parameter extraction algorithm that can be used in high-performance computer-aided-design applications. A range of multilayered interconnect geometries with arbitrary boundaries are analyzed. Different typical configurations of ground placement are considered to verify the applicability of this method. For all such cases, results are compared for admittance, line parameters, and delay giving physical insight on the effect of boundary conditions on them. Compared with existing industry standard numerical field-solvers, like HFSS, the proposed model demonstrates more than 10× speedup within 2% accuracy.     

An Indo-Soviet experiment on anmhd generator test section at the Soviet U-02 facility

This paper summarizes the major results of the joint Indo-Soviet experiment for testing the Indianmhd generator channel section, designed and fabricated at the Bhabha Atomic Research Centre, Bombay, which was carried out at the U-02 facility in Moscow, USSR, in May 1980. The total test duration was 65 hours and included electrophysical tests and life tests under applied electric fields. The main purpose of the tests was to substantiate the physical concepts, computer codes, design features and special processing techniques involved in the development ofmhd generators for the Indian pilot plant at Tiruchirapalli. The experimental observations on the phenomena of heat transfer to the walls, gas dynamics in the channel, electrical characteristics of the generator and near-electrode processes including the analysis of arc spots correlate with the theoretical estimates based on present understanding of the physical processes occuring in similarmhd generators. The post-operational inspection of the channel section and extensive investigation of materials through microscopic analysis, chemical analysis and x-ray analysis are also reported in this paper. The joint test programme has clearly demonstrated the definite operating capability of the test section and has given sufficient information and encouragement for building better and improved channels for the future.     

Synthesis of Nanocrystalline Lanthanum Strontium Manganite Powder by the Urea–Formaldehyde Polymer Gel Combustion Route

Nanocrystalline lanthanum strontium manganite (LSM) powder has been synthesized by combustion of a transparent gel obtained by the polymerization of methylol urea and urea in a solution containing La³⁺, Sr²⁺, and Mn²⁺ (LSM ions). Chemistry of the transparent urea–formaldehyde (UF) polymer gel formation and structure of the gel have been proposed such that the LSM ions act in between the growing UF polymer chains by interacting through NH, OH, and CO groups by co-ordination and prevent polymer self-assembly through inter-chain hydrogen bonding as evidenced from infrared spectrum. Thermally stable structures formed by the decomposition of UF polymer below 300°C undergo combustion in the presence of nitrate oxidant in a temperature range from 350°–450°C. A perovskite LSM phase has been formed by self-sustained combustion of the dried gel initiated with little kerosene. The powder obtained after deagglomeration and calcination at 600°C for 2 h has a D ₅₀ value of 0.19 μm, and the particles are aggregates of crystallites 10–25 nm in size.     

Optical properties of CdS sintered film

Chemical method has been used to prepare cadmium sulphide by using cadmium, hydrochloric acid and H₂S. The reflection spectra of covered and uncovered sintered films of CdS have been recorded by ‘Hitachi spectrophotometer’ over the wavelength range 300–700 nm. The energy band gaps of these films have been calculated from reflection spectra. It is found that the energy band gap of both films is same as 2.41 eV. It is indicated that energy band gap of these films does not change. This value of band gap is in good agreement with the value reported by other workers. The measurement of photocurrent has also been carried out using Keithley High Resistance meter/ Electrometer. This film shows the high photosensitivity and high photocurrent decay. Thus so obtained films are suitable for fabrication of photo detectors and solar cells.     

The effect of boundary conditions on the dynamic stability of orthotropic cylinders using a modified exact analysis

A calculation of overall dynamic response of thin orthotropic cylindrical shells is presented. Due to the obvious importance of the effects of transverse shear deformation and rotary inertia, these terms are included in the analysis. The exact method is modified to predict the dynamic behavior of an orthotropic circular cylindrical shell. The modal forms are assumed to have the axial dependence in the form of a simple Fourier series. By using the present modified exact analysis various aspects such as influence of boundary conditions, changes in shell geometrical parameters, changes in the directions of orthotropy, etc., on the frequencies, mode shapes and modal forces are studied. Analytical results are shown to be in good agreement with some available experimental and theoretical results.     

An investigation into design of fair surfaces over irregular domains using data-dependent triangulation

Design of fair surfaces over irregular domains is a fundamental problem in computer-aided geometric design (CAGD), and has applications in engineering sciences (in aircraft, automobile, ship science etc.). In the design of fair surfaces over irregular domains defined over scattered data, it was widely accepted till recently that the classical Delaunay triangulation be used because of its global optimum property. However, in recent times it has been shown that for continuous piecewise linear surfaces, improvements in the quality of fit can be achieved if the triangulation pattern is made dependent upon some topological or geometric property of the data set or is simply data dependent. The fair surface is desired because it ensures smooth and continuous surface planar cuts, and these in turn ensure smooth and easy production of the surface in CAD/CAM, and favourable resistance properties. In this paper, we discuss a method for construction of C¹ piecewise polynomial parametric fair surfaces which interpolate prescribed ℜ³ scattered data using spaces of parametric splines defined on H³ triangulation. We show that our method is more specific to the cases when the projection on a 2-D plane may consist of triangles of zero area, numerically stable and robust, and computationally inexpensive and fast. Numerical examples dealing with surfaces approximated on plates, and on ships have been presented.     

Phase shift bandwidth and scan range in microstrip arrays by the element frequency tuning

In this paper, the far-field phase shift properties of microstrip patch antennas are investigated. It is shown that, similar to reflectarrays, the resonant nature of microstrip patches can be used to change the phase of the radiated field. This phase change can be caused by the dimensional change of the microstrip patch, or by a reactive loading of its cavity such as an aperture on its ground plane. However, the available phase shift is limited by the antenna impedance bandwidth. The problem is initially investigated for conventional patch antennas, determining the available phase shift range. It is then studied for a wideband E-slot microstrip antenna, showing a considerably larger phase shift range. Then, a micro-electro-mechanical (MEM) based ground plane membrane, activated by an electrode from below, is proposed to adaptively generate and control the required phase shifts. It provides a low loss, continuously variable phase shifter that can be used at high frequencies for beam scanning in small arrays.     

Sex Differences and Individual Differences in Cognitive Performance and Their Relationship to Endogenous Gonadal Hormones and Gonadotropins.

Sexually dimorphic cognitive performance in men (n=42) and women (n=42) was related to testosterone, estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, and sex hormone binding globulin, measured in 10-ml blood samples collected between 0900 and 1030 and, among women, during the follicular phase of the menstrual cycle. Significant sex differences favored men on spatial tasks (Mental Rotation and Judgment of Line Orientation) and on an inhibition task and favored women on a verbal task (category fluency). However, there were no significant relationships between any of the hormones and cognitive performance, suggesting that there are few, if any, consistent, substantial relationships between endogenous, nonfluctuating levels of gonadal hormones or gonadotropins and these cognitive abilities in men or women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)