著者

右田 裕規

出版者

京都大学

巻号頁・発行日

2006-11-24

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新制・課程博士

著者

奥田 ゆかり

出版者

名古屋大学高等教育研究センター

巻号頁・発行日

2009 (Released:2009-03-16)

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2008年度名古屋大学学生論文コンテスト優秀賞(附属図書館長賞)受賞

著者

Okada Susumu Saito Susumu Oshiyama Atsushi

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.65, no.16, pp.165410, 2002-04

被引用文献数

74 83

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We report first-principles total-energy electronic-structure calculations that provide energetics and electronic structures of double-walled BN nanotubes, (n,0)@(15,0) and (m,0)@(20,0). We find that the most favorable double-walled nanotubes studied here are (7,0)@(15,0) and (12,0)@(20,0) in which the interwall distances are about 3 Å. The electronic energy bands around the Fermi energy depend interestingly on the tube radii due to the hybridization between σ and π states. We also find that the nearly-free-electron states of the nanotubes induce peculiar charge redistribution in the interwall region.

著者

Okada Susumu

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.72, no.15, pp.153409, 2005-10

被引用文献数

12 9

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Total-energy electronic-structure calculations were performed to explore energetics and electronic structures of a one-dimensional array of C60 and potassium atoms encapsulated in metallic nanotubes. We find that the electron states of the potassium intercalated peapods depend on the number of potassium atoms intercalated. Intercalation induces substantial hybridization between pi electron states of C60 and the nanotube. The local density of states around the Fermi level shows that the potassium intercalated C60-peapod is a novel metal whose carriers are distributed on both the C60 and the nanotube.

著者

Umeda T. Ishitsuka Y. Isoya J. Son N. T. Janzén E. Morishita N. Ohshima T. Itoh H. Gali A.

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.71, pp.193202, 2005-05

被引用文献数

55

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Carbon vacancies (VC) are typical intrinsic defects in silicon carbides (SiC) and so far have been observed only in the form of positively charged states in p-type or semi-insulating SiC. Here, we present electron-paramagnetic-resonance (EPR) and photoinduced EPR (photo-EPR) observations of their negatively charged state (V_C^-) in n-type 4H-SiC. This EPR center (called HEI1) is characterized by an electron spin of 1/2 in a Si-Si antibonding state of VC. First-principles calculations confirm that the HEI1 center arises from V_C^- at hexagonal sites. The HEI1 spectrum shows a transition between C1h and C3v symmetries due to a fast reorientation effect reflected in the nature of this defect. The photo-EPR data suggest that V_C^2- is the dominant form of VC when the Fermi level lies 1.1 eV below the conduction band.

著者

西澤 由隆

出版者

早稻田大學政治經濟學會

雑誌

早稻田政治經濟學雑誌 (ISSN:02877007)

巻号頁・発行日

vol.370, pp.53-64, 2008-02-20

著者

中村 みどり

出版者

早稲田商学同攻会

雑誌

文化論集 (ISSN:09184589)

巻号頁・発行日

vol.41/42, pp.135-148, 2013-03-15

著者

長江 好道

出版者

北海道大學教育學部 = THE FACULTY OF EDUCATION HOKKAIDO UNIVERSITY

雑誌

北海道大學教育學部紀要 (ISSN:04410637)

巻号頁・発行日

vol.11, pp.199-217, 1965-03

著者

梅村喬 ウメムラタカシ UMEMURATakashi

出版者

大阪大学大学院文学研究科

雑誌

大阪大学大学院文学研究科紀要 (ISSN:13453548)

巻号頁・発行日

vol.40, pp.153-198, 2000-03-15

著者

NIIDA Sumaru UEMURA Satoshi HARADA Etsuko T.

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E96-B, no.8, pp.2069-2075, 2013-08

被引用文献数

2

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As mobile multimedia services expand, user behavior will become more diverse and the control of service quality from the user's perspective will become more important in service design. The quality of the network is one of the critical factors determining mobile service quality. However, this has mainly been evaluated in objective physical terms, such as delay reduction and bandwidth expansion. It is less common to use a human-centered design viewpoint when improving network performance. In this paper, we discuss ways to improve the quality of web services using time-fillers that actively address the human factors to improve the subjective quality of a mobile network. A field experiment was conducted, using a prototype. The results of the field experiment show that time-fillers can significantly decrease user dissatisfaction with waiting, but that this effect is strongly influenced by user preferences concerning content. Based on these results, we discuss the design requirements for effective use of time-fillers.

著者

東島 仁 中川 智絵 山内 保典 三浦 優生 高橋 可江 中村 征樹

出版者

北海道大学 高等教育推進機構 高等教育研究部 科学技術コミュニケーション教育研究部門(CoSTEP)

雑誌

科学技術コミュニケーション (ISSN:18818390)

巻号頁・発行日

vol.11, pp.28-43, 2012-06

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The advancement of science and technology has brought not only positive but also negative influences. As a result, people are finding it important to examine the potential consequences of science and technology and their effects on society. In this paper, we describe a public dialogue to examine the relationship between autism (Autism Spectrum Disorders) and society, with detailed methodology for conducting it. Autism is a lifelong neurodevelopmental disorder; approximately one in 100 people have autism. The study of autism is one of the most active fields of research. The approximately 30 participants in the dialogue included various citizens, for example, entrepreneurs, autistic people, parents of young children with/without autism, educators, artists, and students. After being provided with sufficient information on autism, participants were divided into 5 groups to discuss the topic and offer proposals. Finally, 5 proposals for an autism-friendly society were announced; these can be viewed in English at http://ristex-kanazawa.w3.kanazawa-u.ac.jp/syoppu/Consensus.htm. In each proposal, the importance of collaborating with a variety of sectors such as citizens, medical institutions, schools, and other professionals was mentioned. We hope that these proposals will be a foundation for future discussions on the relationship between autism and society.

著者

齋藤 健司

巻号頁・発行日

2012

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科学研究費助成事業(科学研究費補助金)研究成果報告書:基盤研究(C)2009-2011

著者

安藤 和典

巻号頁・発行日

2012

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Thesis (Ph. D. in Mathematics)--University of Tsukuba, (A), no. 6328, 2012.9.30

著者

Watanabe Yousuke Kitagawa Hiroyuki

出版者

Elsevier B.V.

雑誌

Information systems (ISSN:03064379)

巻号頁・発行日

vol.35, no.1, pp.94-110, 2010-01

被引用文献数

4 7

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With the increasing demands for advanced use of streaming data, efficient execution of continuous queries is an important research issue. This paper focuses on event-driven continuous queries that are activated by foreign events such as data arrival and the progression of time. Existing approaches to multiple continuous query optimization decide the optimal query plan by extracting common subexpressions from the given queries. Event-driven queries containing the common subexpressions may produce many common intermediate results when they are activated within a small interval, but may produce only disjoint data when activated at completely different timings.This paper proposes an efficient data stream processing scheme for multiple event-driven continuous queries. In the proposed approach, we introduce query result caching to achieve a flexible way to share common operators among queries activated by unpredictable events. When a query is activated, an intermediate result generated for the query is stored into the cache area if it is expected to be reused by other queries. When other queries including the same operator are activated, they reuse the cached result if the cache includes reusable data. Efficiency of the proposed scheme is validated by intensive experimental evaluations.

著者

伊藤 光弘

巻号頁・発行日

2012

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科学研究費助成事業(科学研究費補助金)研究成果報告書:若手研究(C)2009-2011

著者

Okada Susumu Oshiyama Atsushi

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.68, no.23, pp.235402, 2003-12

被引用文献数

26

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We report electronic structures and stabilities of rhombohedral C60 polymers by using the local spin-density approximation in the framework of the density-functional theory. Owing to hybrid networks of sp2-like (threefold coordinated) and sp3-like (fourfold coordinated) carbon atoms, the electronic structures of these polymers are considerably different from that of a face-centered cubic (fcc) C60. We find that polymerized structures attained at the double bonds are semiconducting whereas polymerized structures attained at single bonds are metallic. Significant overlap of the wave function in the space among three adjacent C60 causes the metallic behavior on the latter polymers. We also find that the stacking ordering strongly affects the conducting properties of the metallic polymers. Despite substantial density of states at Fermi level, the C60 polymers do not exhibit any magnetic ordering. Total energy calculations show that the metallic C60 polymers have higher total energy than the semiconducting C60 polymer phases.

著者

Okada Susumu Otani Minoru Oshiyama Atsushi

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.67, no.20, pp.205411, 2003-05

被引用文献数

96 93

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We report total-energy electronic structure calculations that provide energetics of encapsulation of various fullerenes in carbon nanotubes and electronic structures of resulting carbon peapods. We find that the electron states of the peapods depend on the space in the nanotubes and that they reflect electron states of the encapsulated fullerenes. The deep energy position of the lowest unoccupied state of fullerenes as well as hybridization between π states of the fullerenes and the nearly free-electron states of the nanotubes causes a multicarrier character in the peapods.

著者

加地 仁保子

出版者

京都大学哲学論叢刊行会

雑誌

哲学論叢 (ISSN:0914143X)

巻号頁・発行日

vol.37, no.別冊, pp.S107-S118, 2010

著者

青木 仕

巻号頁・発行日

2005

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筑波大学博士 (情報学) 学位論文・平成17年3月25日授与 (甲第3830号)

著者

Iida Hiroyuki Nakagawa Takeo Huy Nguyen Quoc Hasai Siti Mardhiah Husna Azizul Nur Muangkasem Apimuk Sone Shogo Ishitobi Taichi

出版者

Institute of Electrical and Electronics Engineers (IEEE)

雑誌

2012 International Conference on Information Society (i-Society)

巻号頁・発行日

pp.415-422, 2012-06-27

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This paper is concerned with uncertainty of game outcome in Congkak and Othello. Firstly, an information dynamic model of uncertainty of game outcome is derived based on fluid mechanics. Secondly, data analyses of Congkak and Othello have been done. It is found that Congkak is a unique regional game in South-East Asia, while Othello is one of the most entertaining games in the globe. It is suggestedthat Shannon’s entropy provides a measure of uncertainty ofgame outcome, but not itself. The true uncertainty is given by the present proposed model.