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Material search with high-speed and efficient scanning tunneling spectroscopy based on machine learning
No full text低温走査トンネル顕微鏡（STM）を用いたトンネル分光イメージングは、二次元表面の欠陥等で散乱・干渉する電子の波を捉え、物質内の電子やその電子が収まっているバンド構造の性質を明らかにする手法である。この手法は、フェルミ面やバンドの構造を極低温・強磁場でも観察できることから、角度分解光電子分光と相補的な測定手法として、その重要性は高い。一方でその測定は長ければ一週間にも及び、STMの高い安定性と高騰を続ける液体ヘリウムを大量に必要とする。そのため、現状では国内でもごく限られた実験室でしか測定を行うことができない。そこで我々は、この測定の高速化を進める研究を行ってきた。これまで、バンド内の単一のエネルギーにおいて観察された電子波の実空間画像から、データ点をランダムに落とし、スパースモデリングを用いて逆問題を数値的に解いて波数空間の干渉パターンを再現することに成功している。この結果は、少なくとも数値実験の範囲内では、1/9のデータ（1/9の測定時間）で同じ情報を獲得できることを意味している。そこで本研究ではこの結果を踏まえて、測定点をランダムに間引いた実測定プログラムの開発を行った。また、それと並行してスパースモデリングと機械学習を用いて、干渉パターンだけでなくバンド構造まで再現する解析手法の開発を行った。開発した実測定プログラムを用いた実験では、単純なバンドを有するAu(111)表面を試料として用いて行った。生成した乱数を用いて測定点の取捨選択を行い、少しずつ測定点を減らしながら測定を行った結果、1/4までデータを減らしたランダム測定を安定に行うことに成功し、フルに測定したデータと同じ情報が得られることが分かった。更に、スパースモデリングと機械学習を用いて最適化を行うことで、ランダム計測によって増大するノイズが除去された高分解能の信号が復元できることが明らかになった。研究課題/領域番号:18H04480, 研究期間(年度):2018-04-01 – 2020-03-31出典：研究課題「機械学習を用いた高効率走査トンネル分光測定による物質探索」課題番号18H04480
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PUBLICLY-18H04480/）を加工して作成金沢大学理工研究域数物科学系research repor
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Scanning tunneling microscopy and spectroscopy on bottom-up fabricated low-dimensional quantum magnets on surfaces
No full text従来、磁石は「向きの自由度のみを持つスピンの集団」として捉えられてきたが、その描像では定性的にもその性質を説明できない低次元量子磁性体(もしくは量子スピン系)の研究が近年盛んに行われおり、化学的手法によって多くの磁性体が合成され調べられている。これに対し我々は、表面上に吸着させた磁性分子を構成要素とし、走査トンネル顕微鏡(STM)を用いて、理想的な低次元量子磁性体をボトムアップ構築し、その磁性を詳細に調べることを目指している。本研究ではその鍵となる技術である、原子・分子マニピュレーションとスピン偏極STMを確立した。In the past, a magnet has been understood as an assembly of classical spins (vectors). In recent decades, however, low-dimensional (low-d) quantum magnets, which cannot be explained with the classical physical picture, have attracted much attention, and various model compounds have been chemically synthesized. We aimed to achieve bottom-up fabrication of ideal low-d quantum magnets on surfaces by single atom/molecule manipulation with the scanning tunneling microscope (STM) and investigate the magnetic properties in detail and locally with spin-polarized STM. To pursue this goal, we succeeded to establish two important key techniques: single atom/molecule manipulation and spin-polarized STM.研究課題/領域番号:23840008, 研究期間(年度):2011 – 2012出典：研究課題「走査トンネル顕微鏡を用いた低次元量子スピン系のボトムアップ構築と局所磁性観察」課題番号23840008
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/ja/report/KAKENHI-PROJECT-23840008/23840008seika/）を加工して作成金沢大学理工研究域数物科学系 / 東京大学research repor
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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