Problems of a continuous change: A follow-up study (1988–1994) in a FMS factory

This article describes economical and sociotechnical changes in a factory workshop during 1988–1994. A large FMS project was realized during the first 2 years. The project was finished on schedule. The project was designed and carried out in a participative manner involving all the personnel in the development groups. The follow-up study shows that the goals concerning the productivity of the workshop and the well-being of the personnel were mainly achieved. There were two main phases in the development: a quick and profound change during the first 2 years, and a more stable, “freezing” phase after it. Challenges, problems, and hindrances to make the development continuous are also discussed. © 1998 John Wiley & Sons, Inc.     

A correction to “Nonmonotonic inconsistency” [Artificial Intelligence 149 (2003) 161–178]

This note corrects an error in the statement and proof of Propositions 9 and 10 of [C. Cross, Nonmonotonic inconsistency, Artificial Intelligence 149 (2) (2003) 161–178]. Both results turn out to depend on the postulate of Consistency Preservation.     

Solidification structure of CaO–SiO2–MgO–Al2O3 (–CaF2) systems and computational phase equilibria: Crystallization of MgAl2O4 spinel

The solidification behaviour of the CaO–SiO₂–Al₂O₃–CaF₂–10% MgO system, which is similar to the inclusion compositions in the stainless steel and the crystallization of spinel have been investigated using XRD, SEM-EDS, and an image analyser. The solidification mode and the phase equilibria were computed by employing thermochemical software. The liquidus temperature of the oxides containing 5% CaF₂ increases with increasing alumina content from 10% to 30%, while the solidus temperature has little dependence on alumina content. The size of spinel crystals in the final microstructure increases on increasing the content of alumina, resulting from that the oxides spending more time at higher temperatures below the liquidus temperature, where crystal growth is generally faster than nucleation, during slow cooling. The liquidus temperature of the oxides containing 30% Al₂O₃ is scarcely varied, while the solidus temperature decreases by increasing the content of CaF₂ to 10%. The size of spinel crystals decreases as the content of CaF₂ increases, resulting from the fact that the oxides could spend more time at relatively lower temperatures, where nucleation is faster than growth, during the cooling process.     

The two-stage recombination operator and its application to the multiobjective 0/1 knapsack problem: A comparative study

In this paper, we first propose a new recombination operator called the two-stage recombination and then we test its performance in the context of the multiobjective 0/1 knapsack problem (MOKP). The proposed recombination operator generates only one offspring solution from a selected pair of parents according to the following two stages. In the first stage, called genetic shared-information stage or similarity-preserving stage, the generated offspring inherits all parent similar genes (i.e., genes or decision variables having the same positions and the same values in both parents). In the second stage, called problem fitness-information stage, the parent non-similar genes (i.e., genes or decision variables having the same positions but different values regarding the two parents) are selected from one of the two parents using some fitness information. Initially, we propose two different approaches for the second stage: the general version and the restricted version. However, the application of the restricted version to the MOKP leads to an improved version which is more specific to this problem. The general and the MOKP-specific versions of the two-stage recombination are compared against three traditional crossovers using two well-known multiobjective evolutionary algorithms. Promising results are obtained. We also provide a comparison between the general version and the MOKP-specific version.     

The Navier–Stokes-αβ equations as a platform for a spectral multigrid method to solve the Navier–Stokes equations

This paper describes a spectral multigrid method for spatially periodic homogeneous and isotropic turbulent flows. The method uses the Navier–Stokes-αβ equations to accelerate convergence toward solutions of the Navier–Stokes equations. The Navier–Stokes-αβ equations are solved on coarse grids at various levels and the Navier–Stokes equations are solved on the “nest grid”. The method uses Crank–Nicolson time-stepping for the viscous terms, explicit time-stepping for the remaining terms, and Richardson iteration to solve linear systems encountered at each time step and on each grid level. To explore the computational efficiency of the method, comparisons are made with results obtained from an analogous spectral multigrid method for the Navier–Stokes equations. These comparisons are based on computing work units and residuals for multigrid cycles. Most importantly, we examine how choosing different values of the length scales α and β entering the Navier–Stokes-αβ equations influence the efficiency and accuracy of these multigrid schemes.     

Underground distribution BPL connections with (N + 1)-hop repeater systems: A novel capacity mitigation technique

This review paper considers the broadband potential of underground low-voltage/broadband over power lines (LV/BPL) and medium-voltage/broadband over power lines (MV/BPL) connections when N repeaters are additively deployed between their existing transmitting and receiving ends (underground LV/BPL and MV/BPL connections with (N + 1)-hop repeater system).