Reflective full‐color LCD using low‐temperature polysilicon TFTs in low‐frequency driving: Analysis of image persistence and flicker with scientific CMOS camera

Image persistence and flicker are major issues for low‐frequency driving of LCDs. Detailed investigation of the mechanisms that produce these phenomena, using image analysis with a scientific CMOS camera, enabled us to reduce it to acceptable levels. We successfully developed a 7.0‐in. WUXGA (1200 × RGBW × 1920) reflective color LCD driven by low‐temperature polysilicon TFTs at 1 Hz.     

Classification error for a very large number of classes

Classification error is analyzed for a situation where the number of possible classes may be on the order of a hundred or more. The error associated with classifying to a single class is shown to depend mainly on average nearest-neighbor distance between class means, noise level, and effective dimensionality of the class mean distribution and not much on other aspects of the distribution, noise correlation, or number of classes. Since single class error is large, separation of classes into groups is also explored. Group classification error has the same properties as single class error but the size of the error is moderated by the Bayes overlap between groups. Standard curves are provided to predict single class and group error. Also discussed are the effect of pattern blurring on classification error and the nearest-neighbor distance statistics throughout a distribution.     

Systematic feature extraction

A systematic feature extraction procedure is proposed. It is based on successive extractions of features. At each stage a dimensionality reduction is made and a new feature is extracted. A specific example is given using the Gaussian minus-log-likelihood ratio as a basis for the extracted features. This form has the advantage that if both classes are Gaussianly distributed, only a single feature, the sufficient statistic, is extracted. If the classes are not Gaussianly distributed, additional features are extracted in an effort to improve the classification performance. Two examples are presented to demonstrate the performance of the procedure.     

Effects of Glass Additions on (Zr,Sn)TiO4 for Microwave Applications

The effects of glass additions on the properties of (Zr,Sn)TiO₄ as a microwave dielectric material were investigated. The (Zr,Sn)TiO₄ ceramics with no glass addition sintered at 1360°C gave Q = 4900 and K = 37 at 7.9 GH_z. Several glasses, including SiO₂, B₂O₃, 5ZnO–2B₂O₃, and nine commercial glasses, were tested during this study. Among these glasses, (Zr,Sn)TiO₄ sintered with ZnO-B₂O₃–SiO₂ (Corning 7574) showed more than 20% higher density than that of pure (Zr,Sn)TiO₄ sintered at the same temperature. A 5-wt% addition of SiO₂, to (Zr,Sn)TiO₄, when sintered at 1200°C, gave the best Q : Q = 2700 at 9 GHz. Results of XRD analysis and scanning electron microscopy and the effect of glass content are also presented.     

Formation of bridges between diamond particles during sintering in molten cobalt matrix

Large diamond particles of about 700 m size mixed with 70 wt% fine cobalt powder have been sintered at 5.25 GPa and 1500 °C after wrapping in zirconium foil. During the sintering treatment faceted inter-particle bridges form, and their pale yellow colour in contrast to the dark yellow colour of the original diamond particles indicates that the bridge is a new phase reduced in nitrogen content because of the gettering effect of the zirconium foil. The morphological characteristics of the bridge and the adjacent particles indicate that the bridge is formed by migration of the inter-particle grain boundary and solution-reprecipitation through the liquid cobalt matrix. It is possible that these processes are induced by the coherency strain energy produced by nitrogen diffusion from the region ahead of the retreating boundaries, as has been observed in metal systems.Presented to 2nd International Conference on New Diamond Science and Technology in poster session, held on September 23–27 1990 in Washington, USA.     

Borrowing Hydrogen Methodology for N‐Benzylation using a π‐Benzylpalladium System in Water

We demonstrate a borrowing hydrogen methodology using the unique reactivity of the π‐benzylpalladium system in water, which offers an efficient and environmentally friendly N‐monobenzylation of electron‐deficient anilines or 2‐aminopyridine with non‐activated benzylic alcohols under neutral conditions. The crossover experiment using benzyl‐α,α‐d₂ alcohol and 3‐methylbenzyl alcohol afforded H/D scrambling products, suggesting that the borrowing hydrogen pathway occurred in our catalytic system. Our simple protocol can accomplish a gram scale reaction of 2‐aminobenzonitrile (76 % isolated yield), and is performed with the use of only 1 mol % Pd(OAc)₂ and 2 mol % TPPMS without other additives in water.

     

A Radical Pathway for Direct Substitution of Benzyl Alcohols with Water‐Soluble Copper Catalyst in Water

We have developed a novel strategy for the direct substitution of benzyl alcohols with anthranilic acids using water‐soluble copper catalysts through a radical pathway in water, which offers efficient and environmentally friendly N‐, S‐, and C‐benzylations under neutral conditions. Radical scavengers strongly inhibited the benzylation. Radical clock experiments using α‐cyclopropylbenzyl alcohol were conducted to observe the rapid isomerization of the cyclopropylmethyl radical to the allylmethyl radical. Hammett plots could be fitted to a two‐parameter Hammett relationship containing both radical and polar contributions [log (k_X/k_H)=−1.24 σ^.–0.38 σ, R²=0.99]. The relative parameter ρ^./ρ of 3.3 suggested that these reactions involved a strong radical character with minor polar influence at the transition state.

     

Trends of intelligent power module

The state‐of‐the‐art Intelligent Power Modules (IPMs) have been reviewed in the beginning of this paper along with a brief overview of its history and the purpose of its development. In the following part, the paper reviews the key IPM concept and the technologies that supported its evolution as a major power electronics component family so far. The paper will also highlight on the status and future possibilities of IPM based power semiconductors for far future power conversion applications. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Effect of Glass Additions on BaO–TiO2–WO3 Microwave Ceramics

The effect of glass addition on the properties of BaO–TiO₂-WO₃ microwave dielectric material N-35, which has Q = 5900 and K = 35 at 7.2 GHz for samples sintered at 1360°C, was investigated. Several glasses including B₂O₃, SiO₂, 5ZnO–2B₂O₃, and nine other commercial glasses were selected for this study. Among these glasses, one with a 5 wt% addition of B₂O₃ to N-35, when sintered at 1200°C, had the best dielectric properties: Q = 8300 and K = 34 at 8.5 GHz. Both Q and K increased with firing temperature as well as with density. The Q of N-35, when sintered with a ZnO–B₂O₃ glass system, showed a sudden drop in the sintering temperature to about 1000°C. The results of XRD, thermal analysis, and scanning electron microscopy indicated that the chemical reaction between the dielectric ceramics and glass had a greater effect on Q than on the density. The effects of the glass content and the mixing process on the densification and microwave dielectric properties are also presented. Ball milling improved the densification and dielectric properties of the N-35 sintered with ZnO–B₂O₃.