Tokyo Institute of Technology

About: Tokyo Institute of Technology is a education organization based out in Tokyo, Tôkyô, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 46775 authors who have published 101656 publications receiving 2357893 citations. The organization is also known as: Tokyo Tech & Tokodai.

Strongly Stable Stationary Solutions in Nonlinear Programs.

Abstract: Publisher Summary This chapter focuses on strongly stable stationary solutions in nonlinear programs. Many studies have been made on the stability or the sensitivity of local minimum solutions to parametric programs. Those studies mainly discussed the continuity of the minimum value of the objective function, the continuity of the set of minimum solutions and/or the continuity of an isolated local minimum or stationary solution with respect to a small change of the parameter vector. In the case where the strict complementarity does not hold, the approach based on the standard implicit function theorem for continuously differentiable maps cannot be used. Various lemmas and theorems are discussed in the chapter. Stationary index, s-stable local minimum solutions, and degenerate s-stable stationary solutions are discussed. An application to a class of continuous deformation methods is reviewed.

Gamma-ray emission from the shell of supernova remnant W44 revealed by the Fermi LAT

Abstract: Recent observations of supernova remnants (SNRs) hint that they accelerate cosmic rays to energies close to ~1015 electron volts. However, the nature of the particles that produce the emission remains ambiguous. We report observations of SNR W44 with the Fermi Large Area Telescope at energies between 2 × 108 electron volts and 3 × 1011 electron volts. The detection of a source with a morphology corresponding to the SNR shell implies that the emission is produced by particles accelerated there. The gamma-ray spectrum is well modeled with emission from protons and nuclei. Its steepening above ~109 electron volts provides a probe with which to study how particle acceleration responds to environmental effects such as shock propagation in dense clouds and how accelerated particles are released into interstellar space.

Weak and Strong Convergence Theorems for a Nonexpansive Mapping and an Equilibrium Problem

Abstract: In this paper, we introduce two iterative sequences for finding a common element of the set of fixed points of a nonexpansive mapping and the set of solutions of an equilibrium problem in a Hilbert space. Then, we show that one of the sequences converges strongly and the other converges weakly.

A novel phosphor for glareless white light-emitting diodes

Abstract: The luminous efficiency of white light-emitting diodes, which are used as light sources for next-generation illumination, is continuously improving. Presently available white light-emitting diodes emit with extremely high luminance because their emission areas are much smaller than those of conventional light sources. Consequently, white light-emitting diodes produce a glare that is uncomfortable to the human eye. Here we report a yellow-emitting phosphor, the Eu(2+)-doped chlorometasilicate (Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2), which can be used to create glareless white light-emitting diodes. The (Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2) exhibits a large Stokes shift, efficiently converting violet excitation light to yellow luminescence, and phosphors based on this host material have much less blue absorption than other phosphors. We used crystal structure analysis to determine the origin of the desired luminescence, and we used (Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2) and a blue-emitting phosphor in combination with a violet chip to fabricate glareless white light-emitting diodes that have large emission areas and are suitable for general illumination.

Interfacial reactions between SiC and aluminium during joining

Abstract: Reactions between SiC and liquid aluminium were studied. Transmission electron microscopy (TEM) showed that aluminium carbide (Al4C3) phase was formed at the interface between pressureless sintered SiC and aluminium. In contrast, the Al4C3 phase was not detected at the reaction sintered SiC-Al interface. This difference in microstructures results in the change in bending strength of the joints. Mixtures of SiC and aluminium powders were heated to react in vacuum in the temperature range 973 to 1473 K and the reaction products were examined using X-ray powder diffraction. It was confirmed that Al4C3 and silicon were formed, and that the extent of reaction between SiC and aluminium was decreased by the addition of silicon into aluminium.