Application of Monte Carlo method to optimal control for linear systems under measurement noise with Markov dependent statistical property

This paper presents an optimal control algorithm for linear systems with measurement noise which has a Markov dependent statistical property. Ordinarily, the optimal control for this problem involves a very large number of sequences, and the usual calculation method becomes impractical. In the algorithm proposed here, the optimal control is calculated with a relatively small number of sequences, sampled at random from the set of all the sequences.

Evidently, the algorithm for a control problem should be obtained directly from the performance criterion. Unlike the state estimation problem, the problem considered here has a difficulty that there exists an interaction between the algorithm and the state of the system. Because of this, a special consideration is required for the design of the algorithm. In this paper control-free measurement data are introduced to establish the convergence of the algorithm and to find a desirable way of sampling the sequences. Then, certain approximations are made to design a practical and efficient algorithm. A few digital simulation results appear to show the effectiveness of the proposed method.     

Mechanism of Ni-Zn Ferrite Formation in the Presence of Molten Li2SO4-Na2SO4

Nickel-zinc ferrite powder was prepared from the constituent oxides in the presence of molten Li₂SO₄-Na₂SO₄. The effect of ZnO on the reactivity of NiO was studied. The process of Ni-Zn ferrite formation was followed by X-ray diffraction and thermomagnetic analyses. Particle size and shape of the product were determined by scanning electron microscopy. In the presence of molten salt, ZnO enhances the reactivity of NiO, and Ni-Zn-ferrite formation is completed at lower temperature than Ni ferrite formation. In the reaction for the formation of Ni-Zn ferrite, Zn ferrite forms before NiO is incorporated into the ferrite phase. The reaction between the initially formed Zn ferrite and NiO leads to a rate of Ni-Zn ferrite formation higher than that of Ni ferrite formation from NiO and Fe₂O₃.     

接枝量对等离子体接枝聚异丙基丙烯酰胺开关的多孔膜的温度感应透过性的影响

The effect of graft yield on both the thermo-responsive hydraulic permeability and the thermo-respousive diffusional permeability through porous membranes with plasma-grafted poly(N-isopropylacrylamide) (PNIPAM)gates was investigated. Both thermo-respousive flat membranes and core-shell microcapsule membranes with a wide range of graft yield of PNIPAM were prepared using a plasma-graft pore-filling polymerization method. The grafted PNIPAM was formed homogeneously throughout the entire thickness of both the fiat polyethylene membranes andthe microcapsule polyamide membranes. Both the hydraulic permeability and the diffusional permeability were heavily dependent on the PNIPAM graft yield. With increasing the graft yield, the hydraulic permeability (water flux) decreases rapidly at 25℃ because of the decrease of the pore size; however, the water flux at 40℃ increases firstly to a peak because of the increase of hydrophobicity of the pore surface, and then decreases and finally tends to zero because of the pore size becoming smaller and smaller. For the diffusional permeability, the temperature shows different effects on the diffusional permeability coefficients of solutes across the membranes. When the graft yield was low, the diffusional coefficient of solute across the membrane was higher at temperature above the lower critical solution temperature (LCST) than that below the LCST; however, when the graft yield was high, the diffusional coefficient was lower at temperature above the LCST than that below the LCST. It is very important to choose or design a proper graft yield of PNIPAM for obtaining a desired thermo-respousive “on/off“ hydraulic or ditfusional permeability.     

Some Roles of MgO and TiO2 in Densification of a Sinterable Alumina

Sinterability of undoped, MgO-doped, and TiO₂-doped Al₂O₃ has been examined by applying reported sintering equations. The order of sinterability was MgO-doped ∼ undoped≪ TiO₂-doped Al₂O₃ in the initial and intermediate stages of sintering, but a relative sintered density at 1600°C for 1 h occurred in the order undoped < TiO₂-doped < MgO-doped AI₂O₃. The dispersion of thermal grooving angles increased in the order MgO-doped < undoped < TiO₂-doped Al₂O₃, The change of sinterability by the dopants is explained in terms of mobility of mass transfer estimated from a densification rate in the initial- and intermediate-stage sintering and of dispersed driving forces of densification and grain growth qualitatively evaluated from the width of the dispersion of thermal grooving angles.     

DEFORMATION BEHAVIOR OF γ-TiAl SINGLE CRYSTALS AT DIFFERENT TEMPERATURES

在－１９６－１１００℃温度范围内,利用压缩试验研究了γ－ＴｉＡｌ单晶（Ａｌ的原子分数为５６％）在「００１」,「１５２」,「０２１」,「２３３」,「１９１」,「２５１」,「１１０」七个晶体取向上的塑性变形行为,它们的屈服强度温度关系曲线都可分成三个部分：－１９６－６００℃屈服强度随温度的升高先是快速下降,达到室温附近以后基本保持不变;６００℃以上,屈服强度随温度的升高而反常升高,随晶体取向的不同在７     

Al2O3纤维砂轮的开发及其磨削特性

细磨粒砂轮用于高精度磨削。然而,由于细磨粒具有较小的结合面积和强度,即使在正常的磨削条件下,磨粒易于从砂轮表面上脱落,导致加工精度与效率低下。近年来,由于Al2O3纤维具有优良的机械与物理化学性能如高强度、高弹性模量、耐磨损、耐高温氧化及耐酸、耐碱等,与基质材料具有良好的相容性,因而被广泛地用于FRP、FRC和FRM等的强化材料。A2O33纤维的平均直径和长度分别为3—5μm和数百μm,比相同直径的细磨粒具有较大的结合面积和强度。因此,1998年以来,日本山口胜美、洞口严教授和中国魏源迁教授使用Al2O3纤维替代磨粒作为磨料,与酚醛树脂结合剂结合,成功地开发了一种A12O3纤维砂轮,能克服磨粒砂轮的缺陷。该砂轮中的纤维排列方向与磨削面相垂直,纤维的端部可用作为切削刃,而且纤维砂轮比磨粒砂轮细密,使用纤维砂轮可实现干磨削和纳米加工。为了考察Al2O3纤维砂轮的磨削特性,本文对难加工材料如模具钢SKD11(HRC60)进行了大量的磨削试验,试验结果表明能获得纳米级加工表面(Ra2．1nm／Ry22nm)。     

The Synergistic Taste Effect of Monosodium Glutamate and Disodium 5'-Inosinate

SUMMARY— The synergistic phenomenon between the taste of monosodium glutamate (MSG) and disodium 5'-inosinate (IMP) [7.5 H₂O] was studied and the relationship expressed as a mathematical model. The phenomenon could be measured quantitatively by fitting the proposed model to the results of the experiment.
The concentration of MSG equivalent to the taste intensity of that given by the mixture of MSG and the ribonucleotide is represented by the following equation:
y = u +γuv
where y is the equivalent taste intensity of the mixture in terms of g/dl of MSG, u is equal to g/dl of MSG in the given mixture, v is equal to g/dl of sodium 5'-inosinate in the given mixture, and γ is a constant.
The γ value for IMP was calculated from extensive sensory testing as 1.218 × 10⁸.     

A Hydrogen‐Storage Distributed Generation System Using Unitized Reversible Cells and Its Operational Scheme

Environmental issues such as global warming and depletion of natural energy resources are posing problems. Photovoltaic systems have been attracting attention as a form of renewable energy. The output power of a photovoltaic system changes sharply because solar radiation intensity and temperature vary with the weather. In conventional photovoltaic systems, the surplus power, excluding the power consumed in the load, flows back to the grid. Therefore, fluctuations in the output power of a photovoltaic system may have an adverse effect on the grid. This paper proposes a novel hydrogen‐storage distributed generation system using a unitized reversible cell that integrates a fuel cell and water electrolyzer to smooth reverse power flow. The hydrogen‐storage distributed generation system was modeled and a computer simulation was performed. Using two evaluation methods, the proposed system is shown to be effective at leveling power flow back to the grid.     

Spline function approach to digital signal processing

Models of digital signal processing are built on the signal spaces composed of spline functions. It is revealed that the models include and generalize the ideal model on the band-limited signal space, and the conventional model used in practice, with a zero-order or a first-order hold circuit. The models can be implemented accurately using real circuits so far as they are not identical with the ideal model because a spline function can be generated as a piecewise polynomial. Thus the models make it possible to treat signal processing systems which exist between the conventional ideal model and the conventional model used in practice, in design through implementation.     

Relaxation optimizing operations in extended probabilistic space

The classical probabilistic relaxation method has been widely used to solve optimization problems in various fields, including image processing and pattern recognition. The authors have also been developing handwritten character recognition system using the probabilistic relaxation method. However, we realize that there exist cases in which a probability theoretic model is inadequate, especially where there exists incompleteness in available information by noise such as patchy segments and ink spots. In that case, we must introduce ad hoc rules for one-to-two correspondence and no correspondence in the probabilistic algorithm. As the Dempster-Shafer (DS) theory is a kind of natural extension of the probabilistic theory by reducing additivity on probability measure and it can cope with incomplete data. This paper proposes a relaxation matching method based on the Dempster-Shafer theory. Then the update process in probabilistic relaxation method is derived as a special case of Dempster's combination rule in DS theory.