Feasibility of multiwavelength Raman spectroscopy was studied as a potentialin-line monitoring technique for grain size distribution in channel poly-Si usedin three dimensional stacked NAND (3D NAND) Flash memory devices. Variouschannel poly-Si materials in 3D-NAND Flash memory devices, converted fromchemical vapor deposition (CVD) grown a-Si, were characterized usingnon-contact, multiwavelength Raman spectroscopy and high resolutioncross-sectional transmission electron microscopy (HRXTEM). The Ramancharacterization results were compared with HRXTEM images. The correlationbetween the grain size distribution characterized by multiwavelength Ramanspectroscopy and “on current” (ION) of 3D NANDFlash memory devices was investigated. Good correlation between these techniqueswas seen. Multiwavelength Raman spectroscopy is very promising as anon-destructive in-line monitoring technique for grain size distribution inchannel poly-Si used in 3D NAND Flash memory devices.

Background: The influences of demographics, culture, language, and environmental changes on Mini-Mental State Examination (MMSE) scores are considerable.

Methods: Using a sample of 7452 healthy, community-dwelling elderly Koreans, aged 55 to 94 years, who participated in the four ongoing geriatric cohorts in Korea, we investigated demographic influences on MMSE scores and derived normative data for this population. Geropsychiatrists strictly excluded subjects with cognitive disorders according to the protocol of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) Clinical Assessment Battery (CERAD-K-C).

Results: Education (standardized β = 0.463), age (standardized β = −0.303), and gender (standardized β = −0.057) had significant effects on MMSE scores (p < 0.001). The score of MMSE increase 0.379 point per 1-year education, decrease 0.188 per 1-year older, and decrease 0.491 in women compared to men. Education explained 30.4% of the scores’ total variance, which was much larger than the variances explained by age (8.4%) or gender (0.3%). Accordingly, we present normative data for the MMSE stratified by education (0, 1–3, 4–6, 7–9, 10–12, and ≥ 13 years), age (60–69, 70–79, and 80–89 years), and gender.

Conclusions: We provide contemporary education-, age-, and gender-stratified norms for the MMSE, derived from a large, community-dwelling elderly Korean population sample, which could be useful in evaluating individual MMSE scores.

Both luminous efficiency and lifetime in blue fluorescence organic light emitting devices (OLEDs) have been improved by modified HTMs with higher LUMO energy levels. The LUMO energy levels of HTM were increased by modifying substituent in HTM molecules. Two HTMs containing ortho and meta biphenyl substituent and one HTM containing thiophene substituent were synthesized via palladium catalyzed amine coupling reactions to compare with a para biphenyl substituent HTM-1 as a standard molecule. According to TDDFT calculations, these three modified HTMs showed 0.05-0.15 eV higher LUMO energy levels compared to the para biphenyl substituent HTM-1. The luminous efficiency and the lifetime (LT90) of OLEDs using HTM-2 at 500 cd/m2 have been enhanced up to 20 % and 52 %, respectively, compared to the standard device using HTM-1.

The YSTAR program is a general sky survey looking for variability. The main equipments are three 0.5-m telescopes. These telescopes have fast F/2 optics covering nearly 3.5 square degree field onto a 2K CCD. They also have very fast slew capability, which exceeds 10 degrees per second. These two factors make them most suitable for rapid target acquisition and wide-field surveys of various kinds. Our primary objective is to identify and monitor variable stars down to 18th R-magnitude, and our observing mode allows the same data set to be also useful in identifying asteroids. Our first telescope has just begun regular automated operation, and the second telescope will be installed in South Africa within this year to provide coverage of the southern sky.

We have constructed an apparatus for in situ measurement of stress of the film prepared by sputtering using an optical non-contact displacement detector. A change of the gap distance between the detector and the substrate, caused by stress of a deposited film, was detected by a corresponding change of the reflectivity. The sensitivity of the displacement detector was 5.9 µV/Å and thus, it was turned out to be good enough to detect stress caused by deposition of a monoatomic layer. The apparatus was applied to in situ stress measurements of Co/X(X=Pd or Pt) multilayer thin films prepared on the glass substrates by dc magnetron sputtering. At the very beginning of the deposition, both Co and X sublayers have subjected to their own intrinsic stresses. However, when the film was thicker than about 100 Å, constant tensile stress in the Co sublayer and compressive stress in the X sublayer were observed, which is believed to be related to a lattice mismatch between the matching planes of Co and X.

We studied the structural and electrical transport properties of incommensurate PbTe-Bi superlattice films. The properties of those samples were noticeably different from those of commensurate samples. For the incommensurate samples, the satellite peaks, in the 9–29 x-ray scans along the [111] growth orientation, became broader and the ratio of satellite intensities to the Bragg intensity became smaller. The resistances of incommensurate samples were about three times larger than those of corresponding commensurate ones. These features are interpreted by an enhancement of the lateral nonuniformity of interfaces in incommensurate samples. The exponential dependence of the resistance on temperature in incommensurate samples was also in contrast to the logarithmic behavior observed in commensurate ones.