ABSTRACT
Learning curves of simple perceptron were derived here. The learning curve of the perceptron learning with noisy teacher was shown to be non-monotonic, which has never appeared even though the learning curves have been analyzed for half a century. In this paper, we showed how this phenomenon occurs by analyzing the asymptotic property of the perceptron learning using a method in systems science, that is, calculating the eigenvalues of the system matrix and the corresponding eigenvectors. We also analyzed the AdaTron learning and the Hebbian learning in the same way and found that the learning curve of the AdaTron learning is non-monotonic whereas that of the Hebbian learning is monotonic.
Subject(s)
Machine Learning , Neural Networks, Computer , Signal-To-Noise RatioABSTRACT
Piezoelectric ceramics of new composition with higher Curie temperature Tc are extensively studied for better piezoelectric microelectromechanical systems (MEMS). Apart from the compositional research, enhanced Tc could be achieved in a modified structure. We have considered that a designed laminated structure of Pb(Zr, Ti)O3 (PZT)-based thin film, i.e., relaxed heteroepitaxial epitaxial thin film, is one of the promising modified structures to enhance Tc . This structure exhibits an extraordinarily high Tc , i.e., [Formula: see text] (bulk [Formula: see text]). In this paper, we have fabricated the designed laminated structure of high Tc (1-x)BiScO3-xPbTiO3. Tc of BS-0.8PT thin films was found to be extraordinarily high, i.e., [Formula: see text] (bulk Tc , [Formula: see text]). Their ferroelectric performances were comparable to those of PZT-based thin films. The present BS-xPT thin films have a high potential for fabrication of high-temperature-stable piezoelectric MEMS. The mechanism of the enhanced Tc is probably the presence of the mechanically stable interface to temperature in the laminated structure. We believe this designed laminated structure can extract fruitful properties of bulk ferroelectric ceramics.
ABSTRACT
We successfully developed sputter deposition technology to obtain a highly c-axis-oriented monocrystalline Pb(Zr, Ti)O3 (PZT) thin film on a Si wafer by fast cooling (~-180°C/min) of the substrate after deposition. The c-axis orientation ratio of a fast-cooled film was about 90%, whereas that of a slow-cooled (~-40°C/min) film was only 10%. The c-axis-oriented monocrystalline Pb(Zr0.5, Ti0.5)O3 films showed reasonably large piezoelectric coefficients, e(31,f) = ~-11 C/m(2), with remarkably small dielectric constants, ϵ(r) = ~220. As a result, an excellent figure of merit (FOM) was obtained for piezoelectric microelectromechanical systems (MEMS) such as a piezoelectric gyroscope. This c-axis orientation technology on Si will extend industrial applications of PZT-based thin films and contribute further to the development of piezoelectric MEMS.
ABSTRACT
Osteosarcoma is a malignant tumor with poor prognosis, and lack of accurate prognostic factors is one of the reasons that make this tumor difficult to cure. The heparin-binding growth factor, midkine is involved in generation and progression of many types of tumors. However, the relationship between midkine and osteosarcoma has been unclear. We show here that midkine is overexpressed in osteosarcoma and the level of midkine expression is correlated with prognosis (P<0.05; log-rank test). Treatment with functional antibodies against midkine suppresses growth of osteosarcoma cell lines, 9N2, 3N1, Saos-2, and NOS-1, to 25-65% of untreated controls. Our results suggest that midkine is useful as a prognostic marker, and is a candidate therapeutic target for osetosarcomas.
