Set-based particle swarm optimization with status memory for knapsack problem

Set-based particle swarm optimization (S-PSO) operates on discrete space. S-PSO can solve combinatorial optimization problem with high quality and is successful to apply to the large-scale problem. In S-PSO, a velocity is a set with possibility and a position is a candidate solution. In this paper, we present a novel algorithm of set-based particle swarm optimization with status memory (S-PSOSM) to decide the position based on the previous position for solving knapsack problem. Some operators are redefined for S-PSOSM. S-PSOSM is a simple algorithm because the state of probability reduces. In addition, the weight of S-PSOSM is discussed. S-PSOSM shows high qualities in experimental results.     

Formation Mechanism of Hydrous-Zirconia Particles Produced by Hydrolysis of ZrOCl2 Solutions: II

The primary and secondary particle sizes of monoclinic hydrous-ZrO₂ particles produced by the hydrolysis of various ZrOCl₂ solutions, with and without the addition of NaCl, CaCl₂, or AlCl₃, were measured using X-ray diffraction and transmission electron microscopy in order to clarify the formation mechanisms of primary and secondary particles. The primary particle size of hydrous ZrO₂, under a constant ZrOCl₂ concentration, decreased monotonously with increasing Cl⁻-ion concentration. On the contrary, the secondary particle size increased monotonously with increasing Cl⁻-ion concentration. The present experimental results revealed that the primary and secondary particle sizes of hydrous ZrO₂ are controlled primarily by the concentrations of H⁺ and Cl⁻ ions produced during hydrolysis, and are independent of the type of added metal ions. The formation mechanisms of the primary and secondary particles of hydrous ZrO₂ were determined on the basis of the present experimental results.     

Sintering Kinetics at Constant Rates of Heating: Effect of Al2O3 on the Initial Sintering Stage of Fine Zirconia Powder

The sinterabilities of fine zirconia powders including 5 mass% Y₂O₃ were investigated, with emphasis on the effect of Al₂O₃ at the initial sintering stage. The shrinkage of powder compact was measured under constant rates of heating (CRH). The powder compact including a small amount of Al₂O₃ increased the densification rate with elevating temperature. The activation energies at the initial stage of sintering were determined by analyzing the densification curves. The activation energy of powder compact including Al₂O₃ was lower than that of a powder compact without Al₂O₃. The diffusion mechanisms at the initial sintering stage were determined using the new analytical equation applied for CRH techniques. This analysis exhibited that Al₂O₃ included in a powder compact changed the diffusion mechanism from grain boundary to volume diffusions (VD). Therefore, it is concluded that the effect of Al₂O₃ enhanced the densification rate because of decrease in the activation energy of VD at the initial sintering stage.     

Let's Dance! The Equivocation in Chalmers' Dancing Qualia Argument

David Chalmers' dancing qualia argument is intended to show that phenomenal experiences, or qualia, are organizational invariants. The dancing qualia argument is a reductio ad absurdum, attempting to demonstrate that holding an alternative position, such as the famous inverted spectrum argument, leads one to an implausible position about the relation between consciousness and cognition. In this paper, we argue that Chalmers' dancing qualia argument fails to establish the plausibility of qualia being organizational invariants. Even stronger, we will argue that the gap in the argument cannot be closed.     

Production of triacylglycerol and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by the toluene-degrading bacterium Rhodococcus aetherivorans IAR1

Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) produced by various bacteria has been intensively investigated as a promising biodegradable plastic, but required a supply of an expensive precursor as a secondary carbon source for its production. In a previous study, we identified a new bacterial strain, Rhodococcus aetherivorans IAR1, which synthesizes PHBV from toluene without the supply of a precursor. Toluene is the volatile organic compound most abundantly emitted to the environment. In the present paper, we show that R. aetherivorans IAR1 produces triacylglycerols (TAGs) simultaneously with PHBV. Both PHBV and TAGs were synthesized before the nitrogen source is completely exhausted. The cellular content of PHBV reached 10% of cell dry weight (CDW) and its synthesis ceased even during intermittent supply of toluene. However, accumulation of TAGs continued during cultivation and their cellular content reached 24% of CDW at the end of cultivation. Cerulenin inhibited TAG production and increased PHBV cellular content up to 30% of CDW. The mole fraction of 3-hydroxyvalerate (3HV) in PHBV produced from toluene increased from 60% to 80% during its accumulation. Fatty acid compositions of TAGs produced from acetate and toluene were different. At the end of cultivation, the mole fraction of C17:0, one of odd-carbon number fatty acids, was 5% on toluene or 10% on acetate while the mole fraction of 3HV in PHBV from toluene was as high as that in PHBV from acetate, suggesting that a C5 intermediate of toluene degradation might directly become a precursor of 3HV whereas propionyl-CoA is required for the incorporation of C17:0 into TAGs.     

Raman Spectroscopic Studies on the Formation Mechanism of Hydrous-Zirconia Fine Particles

The Raman spectra of hydrous-zirconia fine particles produced by the hydrolysis of various ZrOCl₂ solutions were investigated. The Raman spectra of hydrous zirconia synthesized at HCl concentrations below 1 mol/L were similar to those of monoclinic, crystalline ZrO₂; those of hydrous zirconia synthesized at HCl concentrations greater than 1 mol/L showed a crystal structure change. The line width of the Raman bands increased with increasing H⁺ ion concentration. Analyzing the relationship between Raman band width and particle size revealed that the primary particle size of hydrous zirconia was controlled by the H⁺ and Cl⁻ ions, because these ions interfered with the polymerization in a hydrolysis reaction. Based on the experimental results, the formation mechanism for primary particles of hydrous zirconia was determined.     

Phase Transformation of Hydrous-Zirconia Fine Particles Containing Cerium Hydroxide

Monoclinic hydrous-zirconia fine particles that contained cerium(IV) hydroxide (Ce(OH)₄) were heated from 200°C to 600°C, to investigate the phase transformation to CeO₂-doped tetragonal ZrO₂. Both ZrOCl₂·8H₂O and CeCl₃·7H₂O were dissolved in aqueous solutions and then boiled to prepare the hydrous-zirconia particles. The Ce(OH)₄-containing hydrous-zirconia particles were prepared by adding aqueous ammonia into the boiled solutions. The monoclinic-to-tetragonal ( m right arrow t ) phase transformation of the Ce(OH)₄-containing hydrous zirconias was observed at 300°C using X-ray diffraction (XRD). XRD and Brunauer-Emmett-Teller (BET) specific surface area measurements revealed that the Ce(OH)₄-containing hydrous zirconias had a tendency to transform from the monoclinic phase to the tetragonal phase at lower temperatures as the primary particle size of the hydrous zirconia decreased and the Ce(OH)₄ content increased. These tendencies for the m right arrow t phase transformation agree with the conclusions that have been derived from thermodynamic and kinetic considerations.     

Construction of self‐organizing algorithms for vector quantization

Vector quantization is used for both storage and transmission of speech and image data, and an algorithm that minimizes the distortion error is often required. To obtain the minimum distortion error in neural networks for vector quantization, corrective competitive learning has been introduced. In a large number of algorithms, self‐creating neural networks and self‐deleting neural networks have performed well. In this paper, we improve the self‐deleting neural network and propose a generalized algorithm combining the creating and deleting neural networks. First, a few weight (reference) vectors are prepared, the self‐creating algorithm is applied, and vectors are created automatically. Next, the self‐deleting algorithm is applied, and weight vectors are deleted sequentially to reach a predetermined number. Experimental results show the effectiveness of the proposed algorithm. © 1999 Scripta Technica, Electr Eng Jpn, 127(1): 47–55, 1999