ON AND OFF - LINE QUALITY CONTROL FOR PRODUCT DESIGN AND MANUFACTURING PROCESSES

The Taguchi methodology which may be applied as off-line quality control in the product design stage or, as on-line quality control during production is presented. As an off-line quality improvement strategy, it is a preventive measure at the product or manufacturing systems design stage which has the capability of making the product design robust. As an on-line quality improvement strategy, it assists in diagnosing the cause of the variation during production for the purpose of either eliminating the cause of variation or redesigning the product/process to make the product robust against the effect of the variation. The results of a case study presented using a computer program developed show that the Taguchi methodology can lead to substantial improvements

Linking finite-element analysis and computer-aided drafting processes

The aim of this research was to investigate the integration of computer-aided drafting and finite-element analysis in a linked computer-aided design procedure and to develop the necessary software. The Be'zier surface patch for surface representation was used to bridge the gap between the rather separate fields of drafting and finite-element analysis because the surfaces are defined by analytical functions which allow systematic and controlled variation of the shape and provide continuous derivatives up to any required degree. The objectives of this research were achieved by establishing : (i) A package which interpretes the engineering drawings of plate and shell structures and prepares the Be'zier net necessary for surface representation. (ii) A general purpose stand-alone meshed-surface modelling package for surface representation of plates and shells using the Be'zier surface patch technique. (iii) A translator which adapts the geometric description of plate and shell structures as given by the meshed-surface modeller to the form needed by the finite-element analysis package. The translator was extended to suit fan impellers by taking advantage of their sectorial symmetry. The linking processes were carried out for simple test structures, simplified and actual fan impellers to verify the flexibility and usefulness of the linking technique adopted. Finite-element results for thin plate and shell structures showed excellent agreement with those obtained by other investigators while results for the simplified and actual fan impellers also showed good agreement with those obtained in an earlier investigation where finite-element analysis input data were manually prepared. Some extensions of this work have also been discussed

Crystalline Order On Riemannian Manifolds With Variable Gaussian Curvature And Boundary

We investigate the zero temperature structure of a crystalline monolayer constrained to lie on a two-dimensional Riemannian manifold with variable Gaussian curvature and boundary. A full analytical treatment is presented for the case of a paraboloid of revolution. Using the geometrical theory of topological defects in a continuum elastic background we find that the presence of a variable Gaussian curvature, combined with the additional constraint of a boundary, gives rise to a rich variety of phenomena beyond that known for spherical crystals. We also provide a numerical analysis of a system of classical particles interacting via a Coulomb potential on the surface of a paraboloid.Comment: 12 pages, 8 figure

Cellular manufacturing systems design using Tabu search

Abstract: Several techniques have appeared in the literature for the cell formation problem. However, most of these heuristics have the disadvantages that they cannot solve real-life problems typical of manufacturing ®rms in reasonable computational time, and deal with the part family formation and cell grouping problems separately. The Tabu search meta-heuristic is presented for resolving these problems. The minimization of intercellular movements as an objective function is demonstrated, although minimization of cell load variation and the multiobjective function option exist in the procedure developed. The results discussed for some problems taken from the literature show that the Tabu search is a promising technique for solving the cellular manufacturing systems design problem for both medium and large problem instances

TURNOVER INTENTION FACTORS AND ITS EFFECT ON EXTENSION OFFICERS JOB PERFORMANCE IN ONDO STATE, NIGERIA

This study examines the turnover intention factors and its effect on extension officers’ job performance in Ondo State, Nigeria. The study used stratified sampling technique to select 80 extension officers of the Agricultural Development Project in the 4 zones of Ondo State. The data were analyzed using descriptive statistics, correlation, and regression analysis. The results show that extension officers rated level of job performance, emotional intelligence and organizational commitment as high while job satisfaction and leadership member exchange as low. Significant and positive correlation (p<0.01) existed between each variable and work performance. Regression analysis results showed that emotional intelligence, job satisfaction, and leadership member exchange were significant turnover intention factors that affect job performance. The R2 value of 0.731 indicates that the three (3) factors gave 73.1% explanation of the variance in extension officers’ job performance. The results also suggested that emotional intelligence (?=0.734) was the most important turnover intention factor that have effect on job performance, followed by job satisfaction and leadership member exchange. Hence, emotional intelligence, job satisfaction and leadership member exchange should be taken into consideration as turnover intention factors that affect job performance among the extension officers. This study contributes to a better understanding of the relationship of turnover intention factors to job performance and will add to existing body of knowledge in the domain of managing extension officers’ in the agricultural industry, thereby increasing job performance and productivity in the agricultural sector.        Keywords: Extension Officers, Intention, Job Performance, Turnover

Application of response surface methodology to laser-induced breakdown spectroscopy : influences of hardware configuration

Response Surface Methodology (RSM) was employed to optimise LIBS analysis of single crystal silicon at atmospheric pressure and under vacuum conditions (pressure ~10-6mbar). Multivariate analysis software (StatGraphics 5.1) was used to design and analyse several multi-level, full factorial RSM experiments. A Quality Factor (QF) was conceived as the response parameter for the experiments, representing the quality of the LIBS spectrum captured for a given hardware configuration. The QF enabled the hardware configuration to be adjusted so that a best compromise between resolution, signal intensity and signal noise could be achieved. The effect on the QF of simultaneously adjusting spectrometer gain, gate delay, gate width, lens position and spectrometer slit width was investigated, and the conditions yielding the best QF determined

Hybrid Differential Evolution - Scatter Search Algorithm for Permutative Optimization

This chapter deals with modified version of DE algorithm, enriched by scatter search to show its improved performance. Comparison has been done with well known and respected benchmarks.P(GA102/09/1680), Z(MSM7088352102