Two-dimensional merging path generation using model predictive control

A merging path generation method for automated vehicle merging is proposed. This method can make the relevant vehicles cooperate with each other with constraint accelerations, keep the vehicles in their lanes and generate collision free merging path. The merging problem is considered in the two-dimensional space. We set up the mathematic model of the system, formulate the two-dimensional merging problem as an optimization problem and solve it by model predictive control (MPC). To compare the simulation results with the practice, three typical cases were researched. In order to be more practical, the initial conditions of the cases were set according to the data obtained through analyzing the helicopter-shot video. The results represent that the MPC-controlled merging maneuver carried out safely and smoothly, and the relative positions after merging is also the same with the practical results in all the three representative conditions considered. The absolute values of the accelerations of the vehicles are all kept below a practical value 3 m/s². The importance of cooperation in merging maneuver can also be noticed in the simulation results. By letting the relevant vehicles cooperate, this control algorithm would generate collision free merging path even in the very severe condition. The computational time for the three cases is also short enough for the method to be implemented in actual situation.     

Photoinduced paramagnetic defects and negative charge in SiCN dielectrics for copper diffusion barriers

We investigated defect generation in silicon carbon nitride (SiCN) dielectric films subjected to ultraviolet (UV) lights with two different photon energies at room temperature using electron spin resonance (ESR) and electrical measurements. A buildup of negative charge occurred and paramagnetic defects were generated by exposing the SiCN films to 4.9-eV UV illumination. However, a photon energy of 3.4 eV was insufficient to generate the negative charge and paramagnetic defects. The characteristics of the UV-induced ESR signals suggest that the generated paramagnetic defects are neutral silicon dangling bond centers. On the other hand, in the SiCN-SiO₂ stacked film subjected to 4.9-eV UV illumination, no net negative charge accumulated although a large number of paramagnetic defects were generated. This indicates that the generation of paramagnetic defects and the buildup of negative charge are based on different mechanisms. We discussed a consistent picture to explain these phenomena.     

Electronic properties of calcined materials from a scandium-O-phenylene-O-yttrium-O-phenylene hybrid copolymer

Calcination of a scandium-O-phenylene-O-yttrium-O-phenylene hybrid copolymer under an argon atmosphere at 400–800 °C was performed. The calcined materials were found to be composed of nano-sized Sc₂O₃ and Y₂O₃ particles in the matrix of carbon clusters. ESR spectral examinations of the calcined materials suggest that a two-step electron transfer of Y₂O₃ → carbon clusters → Sc₂O₃ → carbon clusters took place to provide a photo-responsive oxidation–reduction function with an oxidation site at Y₂O₃ particles and a reduction site at carbon clusters.     

Effect of centrifugal forces on the instability of the thermocapillary flow in partially confined half-zones

The stability of the axisymmetric steady thermocapillary flow in a cylindrical half-zone liquid bridge is investigated numerically for the case when the free surface is partially confined by a thin solid layer. A linear-stability and an energy analysis are performed to elucidate the dependence of the instability mechanism on the free-surface fraction which is defined as the length of the free part of the cylindrical surface relative to the full height of the zone. It is found that the balance of the elliptic instability and the centrifugal instability changes significantly, leading to three different types of instability depending on the free-surface fraction.     

Syntheses and electronic behaviors of net-worked,alternating hafnium-organic moiety hybrid copolymers

Hafnium-organic moiety hybrid copolymers were prepared by reacting hafnium n-butoxide with organic diols. ESR spectral examinations of copolymers and ab-initio calculations of copolymer models suggest that an electron transfer from organic group to hafnium atom takes place.     

Insulation resistance under DC stress and electrification characteristics of GIS epoxy insulator

Gas‐insulated switchgear (GIS) has widely been used for AC power distribution because of its high reliability and compactness. Recently, DC GIS has been developed with various investigations for dielectric breakdown characteristics of DC gas insulation. GIS insulation is composed of SF₆ gas and solid spacers, and it has been recognized that the dielectric performance of DC GIS is mainly influenced by solid spacers. Under DC stress, the electric field is directed one way, the effect of electrification for charges to be accumulated in the spacer must be taken into account and also the effect exists in AC GIS because the switching operations may leave the remnant DC charge on the AC GIS spacer. This paper first describes the effective resistivity (the bulk or the surface) of the solid spacer under the DC stress from the experimental investigation, and the critical factor on the solid spacer that causes reduced dielectric performance of the GIS insulation is studied. Second, the present paper deals with the electrification on the GIS with various levels of surface roughness of the epoxy insulator and metallic electrode. Finally, the DC insulation characteristics of GIS insulator are investigated based on the experimental results. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(4): 6–13, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20788     

Evidence for two distinct tumor-suppressor gene loci on the long arm of chromosome 11 in human oral cancer

Loss of heterozygosity (LOH) on human chromosome 11 has been reported in a variety of human cancers. To search for the existence of tumor-suppressor gene(s) associated with oral squamous cell carcinoma (SCC) on chromosome 11, we have performed high-resolution deletion mapping in 31 patients with oral SCC using 22 microsatellite markers for this chromosomal region. LOH was observed in 14 of 25 cases (56.0%) that were informative with at least one locus. Most allelic deletions detected in our study were specific to the long arm of the chromosome. Furthermore, the data presented here show 2 distinct, commonly deleted regions. The first region, with frequent LOH, was restricted between markers DIIS939 and DIIS924 separated by 3 centimorgans (cM) on chromosome 11q23. The second region of common deletion was identified between markers DIIS912 and DIIS910, separated by 7 cM at 11q25. Our results suggest that at least 2 tumor-suppressor genes involved in the development of oral SCC are present on the long arm of chromosome 11.     

Phase behavior of the ternary system solvent: poly(γ-benzyl L-glutemate) and polystyrene

Summary Phase equilibria were investigated at 80°C for a ternary system involving a solvent benzyl alcohol, a rodlike polymer poly(-benzyl L-glutamate) (PBLG), and a flexible polymer polystyrene (PS). The fairly dilute solution of the two polymers was isotropic and monophasic. At greater concentrations, it was separated into two isotropic phases. Above an even higher critical concentration of the two polymers, three phases, a cholesteric (A₁) and two isotropic phases (I₁ and I₂), coexisted at equilibrium. PBLG was contained exclusively in the phases A₁ and I₁, while PS was in the phase I₂. The more concentrated solution was separated into a cholesteric phase and an isotropic phase. The latter contained PS but excluded PBLG, These features were discussed on the ground of the Flory theory by considering the polymer compatibility.     

Fabrication and characterization of surface‐conduction electron emitters for SED application

Abstract— A surface‐conduction electron emitter (SCE) for next‐generation flat‐panel displays has been developed. PdO thin films (approximately 10 nm thick) produced by an ink‐jet process were used to form the surface‐conduction electron emitter. The films were electroformed and activated while a voltage was applied, and an electron emitter with good characteristics was obtained. A current density of approximately 30 mA/cm² was attained when an anode voltage of 10 kV was applied. Furthermore, a 36‐in. surface‐conduction electron‐emitter display (SED), consisting of SCEs and a phosphor screen similar to that of a CRT, was also developed.     

X-ray absorption fine structure combined with X-ray fluorescence spectrometry. Improvement of spectral resolution at the absorption edges of 9-29 keV

X-ray absorption near-edge structure (XANES) suffers from core-hole lifetime broadening at a higher energy absorption edge, such as Sn K (29 keV, Gamma(K) = 8.49 eV). To overcome this problem, emitted Sn Kalpha1 fluorescence from sample was counted using high-energy-resolution fluorescence spectrometer in the XANES measurements. Experimental energy resolution (5.0 eV) was consistent with theoretical values based on the Rowland configuration of the spectrometer. The absorption edge became steeper compared to conventional spectra. The white-line peak due to Sn(II) species became remarkably sharper and more intense in the Sn Kalpha1-detecting Sn K-edge XANES for Pt-Sn/SiO2. To support the semiclassical theory of resonant Raman scattering for the explanation of observed elimination of lifetime width, more resolved XANES data at Cu K, Pb L3, and Sn K in this work were convoluted (filtered) with a Lorentzian of each core-hole lifetime width. The processed data resembled generally well corresponding XANES spectrum measured in transmission mode. The verification based on ab initio XANES calculations was also performed.