Naoto Kobayashi

The University of Tokyo

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Chikako Yasui

National Astronomical Observatory of Japan

100

A. T. Tokunaga

University of Hawaii–West Oahu

Hiroshi Terada

National Astronomical Observatory of Japan

Yuji Ikeda

Kyoto Sangyo University

Sohei Kondo

The University of Tokyo

Noriyuki Matsunaga

The University of Tokyo

Masanori Iye

National Astronomical Observatory of Japan

Hideyo Kawakita

Kyoto Sangyo University

Miwa Goto

University of Yamanashi

Satoshi Hamano

National Astronomical Observatory of Japan

Cooperative Institutions

The University of Tokyo

531

National Astronomical Observatory of Japan

Kyoto University

Osaka University

Tohoku University

Centre National de la Recherche Scientifique

176

Nagoya University

170

Hokkaido University

156

University of the Basque Country

150

Tokyo University of Science

140

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Single-photon emission in telecommunication band from an InAs quantum dot in a pillar structure

X. Liu Naoto Kobayashi Kouichi Akahane Masahide Sasaki H. Kumano

We report on the experimental demonstration of single-photon source based on a single InAs quantum dot emitting in the telecommunication band. The low-density quantum dots grown by epitaxial method are embedded in an asetched pillar structure. Photoluminescence spectrum of a single InAs quantum dot exhibits intense and narrow emission lines. Photon antibunching behavior is clearly observed using superconducting single-photon detectors with high sensitivity, which indicates the single-photon emission.

Pillar

Single-Photon Source

10.1109/iciprm.2013.6562567

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Citations (0)

Concatenated error correction coding for high-order PRML channels

H. Sawaguchi M. Kondou Naoto Kobayashi S. Mita

A modified E/sup 2/PRML (ME/sup 2/PRML) channel is optimized for high-density magnetic recording in order to reduce long error-propagation events in an ML detector. A cyclic redundancy-check error-correction code (CRCC), an innerblock ECC concatenated to the ML detector, is introduced as a new ECC-coding scheme for the high-order partial response maximum likelihood (PRML) channel. The CRCC coding can efficiently improve the BER performance with only a few redundant check-bits which intensively correct most-dominant short error-events in the ME/sup 2/PRML detector. A 16/17 coded ME/sup 2/PRML channel in conjunction with a 2.9% redundant CRCC coding can achieve a gain of more than 35 dB over a conventional 16/17 coded EPRML channel at a user density of 2.8.

Coding gain

10.1109/glocom.1998.776474

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Citations (41)

An optical spectrum of the afterglow of a γ-ray burst at a redshift of z = 6.295

Nature (2006)

N. Kawai George Kosugi Kentaro Aoki Tōru Yamada Tomonori Totani

10.1038/nature04498

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Citations (238)

Discovery of Young Stellar Objects at the Edge of the Optical Disk of Our Galaxy

The Astrophysical Journal (2000)

Naoto Kobayashi A. T. Tokunaga

We report a discovery of young stellar objects associated with a molecular cloud at the edge of the optical disk of our Galaxy. This cloud is denoted as Cloud 2 in the list by Digel et al., and it is one of the most distant molecular clouds from the Galactic center known to date, with a probable distance of 15-19 kpc. We found seven red near-infrared (NIR) sources associated with this cloud. Based on our NIR observations and the far-infrared/radio data in the literature, we conclude that most sources are likely to be members of Cloud 2. The geometry of ionized gas, IRAS sources, NIR sources, and molecular cloud suggests that MR 1, an isolated early B-type star near Cloud 2, has triggered the star formation activity in Cloud 2. Our results show that ongoing star formation is present in Cloud 2 and that active star formation can occur in the farthest regions of the Galaxy, where the molecular gas density is extremely low, perturbation from the spiral arms is very small, and the metallicity is similar to that for irregular dwarf galaxies. Cloud 2 is an excellent laboratory in which to study the details of the star formation process in an environment that is similar to that in the early stage of the formation of the Galactic disk.

10.1086/308564

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Citations (32)

An introduction to the Research Excellence Framework: A new research evaluation framework for universities in the UK

Synthesiology English edition (2013)

Ryu Ohtani Mariko Kamo Naoto Kobayashi

This article introduces the Research Excellence Framework (REF): a new research evaluation framework developed by the Higher Education Funding Council for England (HEFCE) to evaluate the research activities of higher education institutions in the UK. To promote excellent research so that its potential effect can be maximized, the REF has three criteria for evaluating institutions: output quality, impact, and research environment. Remarkably, although the purpose of the REF is university evaluation, social impact is explicitly included within the evaluation framework. It is proposed that output quality be evaluated by conventional review with the aid of quantitative bibliometric indicators, such as the number of paper citations. In this article, we introduce the REF, from output to impact, and make recommendations for the evaluation of research for universities in Japan.

Excellence

Research Assessment Exercise

10.5571/syntheng.6.122

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Citations (1)

152 Protective effect of melanin on ultraviolet-induced DNA damage formation and cell killing

Journal of Dermatological Science (1995)

Naoto Kobayashi Atsuo Nakagawa T. Muramatsu Yukio Yamashina Toshihiko Shirai

Ultraviolet

Ultraviolet a

10.1016/0923-1811(95)93867-z

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SUBARU/IRCS near-infrared spectroscopy of the young cluster GLIMPSE9 in the inner galaxy

AIP conference proceedings (2014)

Ryō Yamamoto Kei Fukue Noriyuki Matsunaga Chikako Yasui Satoshi Hamano

We are investigating matallicity distribution in the inner Galaxy with near-infrared (NIR) high-resolution spectroscopy of star clusters, which are significant tracers with accurately estimated distances and ages. We present spectral analysis for two red supergiant stars in GLIMPSE9 cluster, which is a young cluster of a typical cluster mass and located around the Galactocentric distance of 4.2 kpc. Based on NIR spectra (1.47 - 1.79 μm, R ∼ 20000) obtained with IRCS spectrograph at SUBARU 8.2 m telescope, the metallicity of this cluster is estimated to be [Fe/H]∼ − 0.2 dex, which is similar to those of other massive young clusters located in the inner Galaxy. These results may suggest that clusters with such low metallicities commonly exist in the inner Galaxy region and that the metallicity gradient in the outer disk does not simply extend to the inner disk, although the Galactic evolutionary scenario to explain such a chemical distribution remains to be established. Note that our abundance analysis is still in a preliminary stage and all the possible systematic errors should be carefully examined.

10.1063/1.4874046

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Science and technology policy and synthesiology ^|^mdash; Bridging science and values

Synthesiology English edition (2012)

Tateo ARIMOTO Naoto Kobayashi Motoyuki Akamatsu

One of the aims of the Fourth Science and Technology Basic Plan, which was decided by the Government of Japan last August, is to create “solution-seeking” or “issue-driven” innovations such as green innovation and life innovation. The Research Institute of Science and Technology for Society, Japan Science and Technology Agency (JST-RISTEX) is promoting various R&D programs that lead to the implementation of the research results in society. Because this approach is in line with Synthesiology, we talked to Dr. Tateo Arimoto, Director of JST-RISTEX, in a roundtable talk session.

10.5571/syntheng.5.128

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Citations (1)

Streptococcal Infection-related Nephritis (SIRN) Manifesting Membranoproliferative Glomerulonephritis Type I

Internal Medicine (2016)

Ken Iseri Masayuki Iyoda Yasutaka Yamamoto Naoto Kobayashi Oda T

We herein report the case of an 18-year-old boy who developed nephrotic syndrome and hypertension after upper airway inflammation. Post-streptococcal acute glomerulonephritis was diagnosed on the basis of a high antistreptolysin O titer, hypocomplementemia, proteinuria, and microscopic hematuria. A renal biopsy was performed due to persistent proteinuria, and the pathological diagnosis was membranoproliferative glomerulonephritis (MPGN) type I. Glomeruli showed positive staining for nephritis-associated plasmin receptor (NAPlr), a nephritogenic group A streptococcal antigen, and plasmin activity was found in a similar distribution as NAPlr deposition. This rare case of streptococcal infection-related nephritis (SIRN) manifesting MPGN type I supports the histological diversity of SIRN.

Membranoproliferative glomerulonephritis

Nephritis

10.2169/internalmedicine.55.5409

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Citations (8)

Spectroscopy with adaptive optics : spectral slope variation

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2003)

Miwa Goto Yutaka Hayano Naoto Kobayashi Hiroshi Terada Tae‐Soo Pyo

We present a note on low to medium resolution spectroscopy using adaptive optics (AO) system. A special focus is put on the problem of spectral slope variations. In principle a stellar image compensated by AO has a varying point spread function (PSF) strongly dependent on the observing wavelength. Even when the AO is working perfectly, the fraction of the energy in a finite size slit will change with the wavelength. The performance of AO correction is very sensitive to the observing conditions. Spectral slope variations directly connected to the wavelength dependency of the enclosed energy in the slit. Those features common and relatively harmless in conventional spectroscopy such as temporal variation in the seeing, brightness of the targets, imperfect slit peaking, atmospheric differential refraction, and fixed aperture size at spectral extraction, all introduce artificial continuum slopes. The degree of uncertainty in the spectral slope could be serious enough to interfere the observing goals in AO spectroscopy. A case for a spectroscopic observation for low mass stars is presented to demonstrate the problem. We found a steep continuum slope that is unrealistic for a low mass star. We undertook laboratory experiments with a calibration source in the AO system to test if the unrealistic continuum slope could be accounted for by the varying AO performance. In the experiments the "bluing" of the continuum slopes have been confirmed when the light source is dropping off of the slit or the wavefront reference source is faint. The effects are also qualitatively reproduced with calculations done by an AO simulation code.

Guide star

10.1117/12.459251

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Citations (10)