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Applying swarm intelligence algorithms to reinforcement learning of neural networks is practical because they do not rely on gradients. Particle swarm optimization (PSO) is a representatives of swarm algorithms. In this paper, the author experimentally evaluates the effectiveness of PSO in the reinforcement learning of multilayer perceptrons (MLPs), using a pendulum control task. Experimental results demonstrated the successful training of an MLP with 8 hidden units, enabling rapid uprighting of the pendulum. Notably, it was found that increasing the population size rather than the number of iterations allowed PSO to discover better solutions. In PSO, increasing the population size promotes global exploration in the early stages, while increasing the number of iterations enhances local exploitation in the later stages. Based on the results of this experiment, it is evident that in this learning task, early-stage global exploration is more important.

Differences of cell proliferation, cell cycle, and G1/S transition regulatory proteins of gingival fibroblasts derived from nifedipine-reactive patient (NIFr) and nifedipine-non-reactive patient (NIFn) in the presence of basic fibroblast growth factor (bFGF) were investigated to elucidate the mechanism of gingival overgrowth associated with nifedipine, one of the Ca2+-channel blockers. The proliferation rate of NIFr cells in the presence of bFGF significantly increased than NIFn cells. The proportion of NIFr cells that had undergone progression to the S and G2/M phases from the G0/G1 phase significantly increased compared to that in NIFn cells. Increases of pRB (Ser807/811), pCDK2 (Thr160), CDK2, and cyclin E protein levels in NIFr cells were greater than those in NIFn cells. The elevations of pRB (Ser780), RB, and cyclin A protein levels in NIFr cells did not differ from those of NIFn cells. The growth of NIFr cells was greater than that of NIFn cells as a result of the active G1/S transition of NIFr cells, as assessed by the increments of cyclin E, pCDK2, and pRB (ser807/811) protein in NIFr cells. Keywords:: gingival overgrowth, nifedipine, gingival fibroblast, cell cycle

Effects of magnetic fields on the thermal convection in conductive aqueous solutions at ambient temperatures have been studied through heat transport measurements combined with shadowgraph technique-based visualization. The suppression of thermal convection by magnetic field was in fact observed in conductive diamagnetic aqueous solutions of ammonium sulfate. The magnitude of the suppression was found to depend on the applied magnetic field and the electrical conductivity of the sample fluid. These effects are qualitatively understood by assuming that Lorentz force acting on the fluid is a main player. Based on these results, a control method of heat transfer process using high magnetic fields has been demonstrated. It seems feasible to understand the behaviors of liquid metals by using electrolytes aqueous solution combined with a superconducting magnet, since flow conditions thereby are regarded as similar to those for liquid metals in industrial electromagnets. [ABSTRACT FROM AUTHOR]

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We have been developing the scale removal system utilizing superconducting magnet that can remove iron scale from boiler feed-water in a thermal power plant. The scale removal prevents the plants from the reduction in power generation efficiency. Iron oxide scale consists of the ferromagnetic and the paramagnetic particles, and the optimal separation conditions largely differ depending on the magnetic properties of the particles. So, single separation condition may cause the filter blockage by over capture or inadequate capture. We proposed the two-stage magnetic separation according to the magnetic properties of the aggregates, where the ferromagnetic particles are captured in the 1st stage in low magnetic field and field gradient, and then the paramagnetic ones are captured in the 2nd stage in high magnetic field and field gradient. It was shown that two-stage magnetic separation system for the mixture of ferromagnetic and paramagnetic particles is possible by utilizing one superconducting solenoidal magnet. [ABSTRACT FROM AUTHOR]

In the boiler feed-water system of thermal power plants, iron oxide scale is generated due to the corrosion of piping, which decreases the effectiveness of the heat exchanger in the boiler and contributes to reduced power generation efficiency. Scale removal can prevent this phenomenon, which consequently results in decreased carbon dioxide emission. In a previous study, an iron scale removal system was developed using superconducting magnets, and high-gradient magnetic separation (HGMS) experiments were conducted using the height difference between the inflow and outflow tanks. As a result, particles were intensively captured by the filters at the inflow side. We succeeded in eliminating this capture by properly controlling the applied magnetic field. However, because the suspension also flowed due to the height difference in this experiment, the problems of partial blockage of the filter and the resulting decrease in the flow rate were not resolved even under the controlled magnetic field. In this study, HGMS experiments were conducted under a constant flow rate with a large pump in a large-scale system having a filter diameter of 300 mm to simulate a boiler feed-water system or chemical cleaning line. Furthermore, we investigated the feasibility of the large-scale HGMS system and elucidated the scale-up effect on the amount captured and the spatial distribution of the captured particles on the filters. Based on these results, a plant-scale HGMS system (800 mm filter diameter) was designed. [ABSTRACT FROM AUTHOR]

Assuming that the high‐gradient magnetic separation (HGMS) system based on a superconducting magnet can reduce iron oxide scale in boiler feedwater and contribute to the efficient operation of thermal power plants, we design a new matrix structure, which should efficiently capture iron oxide particles in boiler feedwater. We then evaluate their practicability experimentally and confirm that this HGMS system with the newly developed matrix is applicable to thermal power plants with the desired efficiency. On the bases of the results, we designed practical large‐scale HGMS systems for boiler feedwater with a superconducting magnet and new matrices, which has long cleaning cycles and low‐pressure loss. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

We are developing a superconducting magnet system that can, on the ground, control gravitational force on protein crystal solutions through use of magnetic forces. Magnetic forces give rise to a variety of effects on motions of protein solutions. We proposed a dynamical model of fluid and material flow in solution under gravity and magnetic force in our previous works. The numerical calculation results showed that magnetic forces could suppress convections and lead to unexpected concentration distributions of solutes under some hypothetical conditions. In this paper, we present some simulation results under actual conditions in a superconducting magnet. The results show that inhomogeneity of magnetic force affects modifies concentration and convection distributions. [ABSTRACT FROM PUBLISHER]

The magnetic chromatography (MC) is a very useful system for an ion and/or fine magnetic particle separation due to its strong magnetic field gradients in a very small flow channel. We have not only developed the MC system to separate the fine particles and ions, we have also developed the numerical analysis computer code based on the fluid dynamics and electromagnetism to investigate the separating characteristics and to optimize design of magnetic column. In this paper, we studied MC technology for magnetic particles and ion separations using micro-scale magnetic column with ferromagnetic wires experimentally. The influences of the strength of magnetic gradient, flow velocity and coefficient of viscosity of solvent were studied by the developed computer code. [ABSTRACT FROM AUTHOR]

A workbench magnet that generates magnetic fields on a room-temperature (RT) plate was developed. The magnet did not have a RT bore. The improvement of accessibility to magnetic fields has made several types of processing and measurement easier. The magnet provides external fields, magnetic fields in the vicinity of the top of a winding, of a solenoid coil on the RT plate. The external fields depend strongly on the gap between the RT plate and the top of the winding. The magnet was a cryocooled superconducting magnet with a 1-W GM cryocooler at 4 K. The magnet successfully generated magnetic fields of over 3 T at the center of the RT plate. The magnet could generate magnetic fields more than twice the surface magnetic fields of permanent magnets with the same accessibility. [ABSTRACT FROM AUTHOR]

We concluded high gradient magnetic separation experiments of iron (ferromagnetic) nano-particles with a nominal diameter of SO nm by using a superconducting magnet. In the experiment, we fabricated fine iron particles using a thermal reactive plasma method in argon and hydrogen mixed gas and sent them directly to the magnetic separator. We present the experimental results, functions of the capture ratio on the magnetic flux density, and velocity of flow. We conclude that high gradient magnetic separation can separate nano-particles and is useful for nano-technology. [ABSTRACT FROM AUTHOR]

A computational fluid dynamics (CFD) model was developed for High Gradient Magnetic Separation (HGMS) of particles in liquids flowing through magnetic filters. Using this model, we simulated the effect of fluid flow, magnetic forces, and particle diffusion on the particle filtration efficiency in an HGMS liquid particle filter. By simulating capture efficiency of the simple configuration, the overall filtration efficiency of HGMS filters can be determined. This paper describes this numerical model and simulation results for an HGMS liquid particle filter. [ABSTRACT FROM AUTHOR]

We have developed a High Gradient Magnetic Separation (HGMS) system to remove arsenic from geothermal water and to supply hot water for public use by using a superconducting magnet. We attained the reduction of arsenic concentration to 0.015 mg/L that is less than the standard for discharge of 0.1 mg/L and slightly larger than the environmental standard of 0.01 mg/L in Japan. The system consists of a pretreatment process that adds extra magnetization to arsenic by chemical reaction, and a reciprocal HGMS filter using a superconducting magnet that extracts magnetized arsenic from the geothermal water. We present the experimental results of the removal system. [ABSTRACT FROM AUTHOR]

Examines the removal efficiency of high-gradient magnetic separation (HGMS) technology. Use of superconducting magnets for HGMS; Separation of fine particles of hematite and iron hydroxide; Magnetic susceptibilities of the weakly magnetized particles.

We have developed a superconducting magnet system generating magnetic forces able to compensate gravity and suppress convection of diamagnetic protein solution from which protein crystals precipitate. A simulation model has been proposed to elucidate the motion of protein solutions and search for the optimal conditions of the crystal formation process. This model incorporates general, non-uniform magnetic forces as external forces, while the previous models involve only simple, uniform magnetic forces. The simulation results indicate that the vertical component can suppress the convection of protein solution, while the horizontal component induces minimal convection. We, therefore, need to take into account the both components when considering the formation of protein crystals under magnetic forces. [ABSTRACT FROM AUTHOR]