Intelligent position/force controller for industrial robotmanipulators-application of fuzzy neural networks

An intelligent controller, which consists of an intelligent planner and an adaptive fuzzy neural position/force controller, is proposed for a robot manipulator. The proposed controller deals with the human expert knowledge and skills for planning and control. In this paper, it is applied to the task of deburring with an unknown object. The effectiveness of the proposed controller is evaluated by computer simulations     

Structure and composition of artificially synthesized rusts of Zn-Fe and Zn-Ti alloys

The artificial rusts of Zn-Fe and Zn-Ti alloys were synthesized from aqueous solutions of mixed metal chloride, sulphate, and nitrate such as ZnCl₂-FeCl₂, ZnSO₄-Ti(SO₄)₂, Zn(NO₃)₂-Fe(NO₃)₃, and so forth, and were characterized by a variety of techniques. Rust particles with different compositions and morphology were formed, strongly depending on the types of anions and metal ions. Sheet particles of basic zinc chloride (simonkolleite) were generated in the ZnCl₂-FeCl₂ system and the plate particles of basic zinc sulphate were formed in sulphate systems. These sheet or plate particles and the nanoparticles produced in Zn-Ti systems are expected to form compact rust layers by preferred orientation and dense packing, respectively, and contribute to a high corrosion resistance of Zn alloys.     

Localized Corrosion in Copper Tubes by Volatile Organic Substance

Anunusualmodeofcorrosionincoppertubes,whicharewidelyusedinrefrigeratingandair-conditioningaams,wasdetectedduringtheearlystageofserviceandinleakagetestsconductedaftermanufacturing[l--161.Themorphologyofthiscormsionissimilartoanat'snestWhenviewedincros...     

Fabrication and optical properties of Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) thin films on Si substrates using the PLD method.

Epitaxial 0.67Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3)-0.33PbTiO(3) (PMN-PT) thin films with electro-optic effects were fabricated on (PMN-PT) thin films with electro-optic effects were fabricated on (La0(0.5)Sr0(0.5))CoO(3) (LSCO)/CeO(2)/YSZ-buffered Si(001) substrates using double-pulse excitation pulsed laser deposition (PLD) method with a mask placed between the target and the substrate. Epitaxial growth of PMN-PT thin films was undertaken using the two-step growth method of PMN-PT film. The PMN-PT seed layer was deposited at 500 degrees C on the LSCO/CeO(2)/YSZ/Si, which temperature was the same as that used for LSCO deposition. The PMN-PT thin films were deposited on the PMN-PT seed layer at 600 degrees C, which enables growth of high-crystallinity PMN-PT films with smooth surfaces. We obtained optimum fabrication conditions of PMNPT film with micrometer-order thickness. Resultant films showed high crystallinity with full width at half maximum (FWHM) = 0.73 deg and 1.6 mum thickness. Electro-optic properties and the refractive index value were measured at 633 nm wavelength using the prism coupling method. The obtained refractive index was 2.59. The electro-optic coefficients r(13) and r(33) were determined by applying the electrical field between a semitransparent, thin top electrode of Pt and a bottom LSCO electrode. The electro-optic coefficient was r(13) = 17 pm/V at transverse electric field (TE) mode and r(33) = 55 pm/V at transverse magnetic field (TM) mode.     

Disturbance suppression beyond Nyquist frequency in hard disk drives

In conventional hard disk drives, a control system compensates for vibration in which the frequency is higher than the Nyquist frequency by using a multi-rate filter that decreases the gain above the Nyquist frequency. However, such a control system can only avoid instability and cannot suppress disturbances above the Nyquist frequency. To overcome this problem, a control system design method that suppresses disturbances beyond the Nyquist frequency is proposed. This method uses frequency responses of a controlled object and a digital controller to calculate the gain of the sensitivity function in a sampled-data system without requiring complex calculations involving matrices, and realizes a stable resonant filter that decreases the gain of the sensitivity function above the Nyquist frequency. Significant suppression of the vibrations caused by the disturbances beyond the Nyquist frequency is demonstrated by implementing this method in the head-positioning system of a hard disk drive.     

Nonstoichiometric deep levels in Mg-doped GaP epitaxial layers

We have investigated the relation between deep levels in Mg-doped p-type GaP liquid phase epitaxy (LPE) layers and stoichiometry of the surface of the substrates by PHCAP measurement. Concentration of a deep donor level at E_C−1.9–2.1 eV is higher in an n-type undoped GaP substrate annealed with applying phosphorus vapor pressure of 20 kPa than in sample annealed beneath a carbon cover. Next, Mg-doped LPE layers are grown on substrates that have been pre-annealed under phosphorus vapor pressure just before the growth. The densities of deep levels at E_V+0.85 and E_V+1.5 eV in long-time (2 h) pre-annealing sample are greatly decreased, but a deep level at E_C−1.9–2.1 eV shows opposite tendency. The latter is thought to be identical to a deep level detected in the substrate, probably phosphorus interstitial atoms.     

Carcinoembryonic antigen and neutrophils in healthy smokers

Although the use of sheep in total artificial heart (TAH) implantation has many advantages, they are known to show a significant morbidity rate on cardiopulmonary bypass (CPB); this has been considered to be a major limiting factor in using them for TAH experiments. We conducted a series of ovine CPB experiments to evaluate the sheep's pathophysiological response to CPB. CPB-related hemolysis, bleeding, and lung dysfunction were analyzed in 5 sheep, which had undergone CPB, used at our hospital for TAH implantation. Four of the 5 sheep survived the experimental procedures, and 3 of them survived on a long-term basis. Unacceptable degrees of hemolysis related to CPB were not observed. Postoperative bleeding was not remarkable, and coagulation test results did not show significant abnormal findings. Acute lung injuries of a mild to moderate degree were found mainly at the microscopic level, but rarely had clinical significance. In conclusion, this experiment suggests that sheep can be used for the animal model for TAH implantation with acceptable risk on CPB circuits and techniques are used.     

Coexpression of cholesterol sulfate and cytokeratin as tumor markers in well-differentiated squamous cell carcinoma of the human uterine cervix

The expression of cholesterol sulfate (CS) is known to increase during squamous differentiation of keratinocytes and to activate the epsilon, eta, and zeta forms of protein kinase C as a signal transduction molecule for the subsequent expression of transglutaminase-1 (TG-1) and cytokeratins. To gain further insight into the regulation of cellular differentiation and tumorigenesis by CS, we examined the concentration and the potential for synthesis of CS in seven and four surgical specimens from human ovarian and uterine cervical cancer patients, respectively, and eight cell lines established from human uterine cervical cancer patients and compared them for the rate of expression of cytokeratin. CS was present in all of the uterine cervical cancer tissue specimens but only in the mucinous type of cystadenocarcinoma among ovarian cancer tissue specimens, and cytokeratin was highly expressed in the tissues with a high concentration of CS, which were classified as well-differentiated on the basis of morphological examination. Similarly, cells derived from a keratinizing type of well-differentiated cervical carcinoma demonstrated strong potential for synthesis of CS, stained positive with anti-cytokeratin antibody, and exhibited a higher specific activity of TG-1, whereas the cells without CS did not stain positive with anti-cytokeratin antibody and exhibited a lower specific activity of TG-1. These findings indicate that CS is coexpressed with TG-1 and cytokeratin in the well-differentiated types of squamous cell cancers as a tumor marker.