Design of nonlinear controllers for active vehicle suspension with state constraints

Design of active vehicle suspension has tradeoffs between three main performance metrics (passenger comfort, suspension deflection and road holding ability). It has been known that each performance can be achieved by H _∞ controller and they can be gathered by LPV (Linear Parameter Varying) method. However, because the suspension deflection limit was not explicitly considered, this limit may be exceeded. In this paper, the authors propose a “reference shaping“ based method in order to improve the control performance. In this approach, a “virtual reference” signal is imposed to the system such that the suspension deflection is kept small. The effectiveness of the approach is examined by numerical simulations. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Suppression of photo-induced dilation in cyanide treated hydrogenated amorphous silicon films

Effects of cyanide (CN) treatment with hydrogenated amorphous silicon (a-Si:H) films have been investigated. The decrease of ΔV/V was observed in cyanide treated a-Si:H films and the successive thermal annealing at 200°C after CN treatment induced the further reduction of the ΔV/V. XPS spectra show the indirect evidence that the cyanide species is present within 10 nm from the hydrogenated amorphous silicon surface. The results of CN treatment with a-Si:H solar cells are demonstrated.     

Identification of creep damage variable from A-parameter by a stochastic analysis

Identification of creep damage variable D of continuum damage theory from the metallographic A-parameter is discussed. By performing a stochastic analysis, A-parameter, defined as the observed fraction of cavitated grain boundaries on the observation plane, was first related to the cavity area fraction on the grain boundary facet planes. Based on the results of this analysis, the cavitation damage states of some engineering alloys were estimated by use of the data of the measured A-parameter. Finally, according to the usual interpretation of the damage variable D, specific D-A relations were derived. The validity and the utility of the proposed D-A relations, based on the test results of an engineering alloy, are discussed.     

Effect of the ACAT inhibitor, HL-004, on cholesterol metabolism in macrophages

The effects of a novel acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor, HL-004, on cholesterol metabolism were examined in mice peritoneal macrophages. Cholesteryl ester-rich foam cells were induced by incubating macrophages with acetylated LDL. HL-004 prevented the accumulation of cholesteryl ester in the presence of the cholesterol acceptor, HDL. In the absence of HDL, HL-004 generated large amounts of free cholesterol in the cell. Moreover, HL-004 stimulated the efflux of cholesterol from preestablished foam cells in the presence of HDL. These results suggest that the inhibition of foam cell formation and the stimulation of foam cell regression by HL-004 are attributed to intracellular ACAT inhibition, and that HL-004 would be expected to exhibit an antiatherosclerotic effect through direct action on arterial wall.     

Internal excitation of intermediate mass fragments from collisions of 36Ar+Ag nuclei at 35 MeV/nucleon

An extruding wire knife was used to give adult male CFHB rats a minimally traumatic unilateral mechanical lesion of the medial forebrain bundle. In addition, some rats received bilateral intrastriatal injections of one of three fluorescent retrograde tracers either eight days before or eight days after the lesion. Injections made after the lesion revealed that about half of the animals had complete lesions of the nigrostriatal tract, while the other half were incompletely lesioned, the mean proportion of non-axotomized neurons being 23%. Over the 10 weeks following the lesions, the number of tyrosine hydroxylase-immunoreactive cells in the lesioned substantia nigra fell linearly, reaching a mean of 29% of that of the control substantia nigra. In the animals which were completely lesioned, neuronal survival at 10 weeks varied between 6 and 12%. That the disappearance of tyrosine hydroxylase-immunoreactive neurons was due to cell death rather than the loss of tyrosine hydroxylase itself was confirmed by labelling the cells with Fluoro Gold before axotomy; the tracer was seen in survival neurons, microglia and in a few involuted neurons which continued to be tyrosine hydroxylase-immunoreactive. This percentage of neurons surviving axotomy corresponds to the proportion of substantia nigra neurons which project to the contralateral striatum, and these neurons were in the region of the substantia nigra from which the contralateral projection originated. It is concluded that following mechanical transection of the nigrostriatal tract, all truly axotomized substantia nigra neurons die over a period of about 10 weeks.     

Effects of intravenous lansoprazole on acute gastric mucosal lesions and acid secretion

The effects of lansoprazole given intravenously on gastric mucosal lesions, gastric bleeding and acid secretion were investigated in rats in comparison with those of omeprazole, famotidine and ranitidine. Lansoprazole inhibited the formation of gastric mucosal lesions in rats induced by water-immersion stress or aspirin with ID50 values of 0.26 and 0.99 mg/kg, respectively, and also inhibited gastric bleeding induced by hemorrhagic shock or water-immersion stress with ID50 values of 0.46 and 1.22 mg/kg, respectively. Lansoprazole was more potent than omeprazole, famotidine and ranitidine in inhibiting gastric mucosal lesions and hemorrhagic shock- or stress-induced bleeding. Famotidine and ranitidine showed negligible inhibition of water-immersion stress-induced gastric bleeding. Lansoprazole strongly inhibited water-immersion stress-stimulated acid secretion in rats, whereas famotidine and ranitidine did not show a potent inhibitory effect. These results indicate that lansoprazole exerts prominent inhibitory actions against the formation of gastric mucosal lesions and gastric bleeding by inhibiting acid secretion, and they show that it is superior to histamine H2-receptor antagonists in inhibiting stress-induced gastric bleeding.     

Identification of Eucalyptus citriodora clones micropropagated in tissue culture

The extent of genetic identity observed in the young individuals which were micropropagated from a single Eucalyptus individual was analyzed by using DNA-fingerprinting. Among 40,000 tissue-cultured-seedings of E.citriodora, 200 plants were randomly chosen so that each total DNA might be extracted from their leaves. Using these DNAs as template, PCR was performed with some primers we found in advance that leads polymorphism for DNA of E. citriodora. In this study, all over the 200 cases, the band pattern formed cDNA fragment on a gel after electrophoresis was the identical one mutually.     

Software‐processed edge‐ and level‐adaptive overdrive (SELAO) method for high‐quality motion pictures

Abstract— In this paper, a software‐processed edge‐ and level‐adaptive overdrive (SELAO) method, which is a novel overdrive technique that utilizes not only a temporal change of gray levels but also a spatial edge intensity of motion pictures, is proposed. The SELAO method is a software video‐processing technology to improve motion‐picture quality rendered on LCDs more than is possible with a conventional SLAO method without edge‐adaptive overdrive, and it works in real time on commonly used personal computers (PCs).     

Torque sensorless control in multidegree-of-freedom manipulator

A torque sensorless control for a multi-degree-of-freedom manipulator is described. In the method, two disturbance observers are applied to each joint. One is used to realize a robust motion controller. The other is used to obtain a sensorless torque controller. A robust acceleration controller based on the disturbance observer is shown. To obtain the sensorless torque control, it is necessary to calculate the reaction torque when the mechanical system performs a force task. The calculation method for the reaction torque is explained. Then the method is expanded to workspace force control in the multi-degree-of-freedom manipulator. Several experimental results are shown to confirm the validity of the proposed sensorless force controller     

K(ATP) channels contribute to the cardioprotection of preconditioning independent of anaesthetics in rabbit hearts

The contribution of ATP sensitive potassium (K(ATP)) channels to the infarct-size limiting effect of preconditioning is considered to be anaesthetic-dependent in the rabbit heart. It has previously been reported that ischaemic preconditioning prevents ischaemia-induced reductions in activities of sarcolemmal adenylate cyclase (AC) and Na+, K(+)-ATPase. Anaesthetic dependency of the role of K(ATP) channels in the preservation of these enzyme activities, induced by ischaemic preconditioning, as well as that induced by activation of A1-adenosine receptors, was examined in rabbits anaesthetized with either pentobarbital or ketamine-xylazine and subjected to 20 min of regional ischaemia. Adenylate cyclase and Na+, K(+)-ATPase activities were lower in the ischaemic than in the non-ischaemic region of the hearts in control rabbits, but not in animals subjected to ischaemic preconditioning, or those pretreated with the A1-adenosine receptor agonist R(-)-N6-(2-phenylisopropyl) adenosine. The protective effects of both ischaemic preconditioning and A1-adenosine receptor activation were prevented by 6 mg/kg, but not 3 mg/kg, of the K(ATP) channel blocker, glibenclamide, in rabbits anaesthetized with pentobarbital, while these effects were prevented by 3 mg/kg of the blocker in rabbits anaesthetized with ketamine-xylazine. Moreover, K(ATP) channel opener, cromakalim, prevented the ischaemia-induced decreases in enzymatic activities in rabbits subjected to either type of anaesthesia. Thus, although the antagonistic effect of glibenclamide is blunted under pentobarbital, compared to ketamine-xylazine anaesthesia, K(ATP) channels contribute to preservative actions independent of the type of anaesthesia in the rabbit heart.