1,720,980 research outputs found
Evaluation of organ-absorbed dose in ECG-gated coronary CTA
Get PDFECG同期冠動脈CTAを施行する場合であっても,撮影法,心拍数によって胸部臓器の吸収線量は大きく異なることが確認された.BEIR VII Phase 2 reportより推定した肺がんの発生リスクは,ECG同期高速二重螺旋スキャン法では0.006%,ECG同期非螺旋スキャン法では0.034%,ECG同期螺旋スキャン法では0.073%であった.ECG同期冠動脈CTAを施行する際には,それぞれの撮影方式は適切に選択されるべきであり,ECG同期高速二重螺旋スキャン法では,画質の劣化を伴うことへのリスクも注意深く考慮する必要がある.It was confirmed that radiation doses absorbed by thoracic organs during ECG-gated coronary CTA were different according to the acquisition technique and heart rate. The estimated lifetime attributable risks of lung cancer incidence in patients who underwent ECG-gated coronary CTA were 0.006% with the ECG-gated high-pitch dual-spiral mode, 0.034% with the ECG-gated step-and-shoot mode, and 0.073% with the ECG-gated low-pitch spiral mode, respectively. Each acquisition mode should be selected appropriately, and it is necessary to carefully consider the risk for deterioration of image quality when the ECG-gated high-pitch dual-spiral mode is applied.出典：研究課題「ECG 同期冠動脈 CTAにおける臓器吸収線量の評価」課題番号21791175
（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/report/KAKENHI-PROJECT-21791175/21791175seika/）を加工して作成金沢大学医薬保健研究域保健学系research repor
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Development and Evaluation of Multi-step Dose Evaluation Method in X-ray Computed Tomography
Get PDFA study was conducted with the aim of easily and accurately acquiring the patient dose information required before and after CT imaging. In order to improve the estimation accuracy of size-specific dose estimate (SSDE) before CT scan, it was necessary to apply the correction method to each cross section in the body axis direction. In addition, the dose data of each organ of the patients was analyzed, and a positive correlation was found between the equivalent dose and SSDE in all the organs included in the acquisition range. In order to estimate the organ doses in detail after CT imaging, a dose calculation program corresponding to CT was developed using the Monte Carlo simulation code and it was shown that the absorbed doses can be calculated with high accuracy. Furthermore, improvements have been made to make the dose calculation program compatible with various types of dual-energy CT.CTの撮影前および撮影後のそれぞれで必要とされる被ばく線量情報を，簡便かつ精度よく評価するための研究を行った．CT撮影前のsize-specific dose estimate（SSDE）の推定精度向上のためには，体軸方向における各横断面で補正手法を適用する必要があった．また，各臓器の線量データを解析し，その等価線量とSSDEとの間には正の相関が認められた．CT撮影後に各臓器の線量を詳細に推定するために，CTに対応した線量計算プログラムを開発し，高い精度で線量が計算できることを示した．さらに，この線量計算プログラムを各種方式のdual-energy CTに対応できるよう改良を進めた．研究課題/領域番号:18K07746, 研究期間(年度):2018-04-01 – 2022-03-31出典：研究課題「CT撮影における多段階線量評価法の開発と評価」課題番号18K07746
（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-18K07746/18K07746seika/）を加工して作成research repor
Variations on the Author
Get PDF“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
Get PDFWe 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
Radiation dose analysis and development of various dose optimization methods in dual-energy CT
Get PDFDual-energy CT（DECT）における被検者被ばく線量の最適化を実現させることを目的に，DECTの被ばく・画質評価，自動露出機構（AEC）の動作特性の解析，仮想非造影画像の精度に関する物理的・臨床的評価を実施した．その結果，DECTはSingle-energy CT（SECT）と比較して画質はわずかに劣るものの，より低被ばくでの撮影を実施できることが確認された．また，TCMのDECTにおける動作特性はSECTとは異なり，特に体格の大きい被検者において不適切であった．また，仮想非造影イメージングの精度は，収集プロトコル，被検者の体格，造影剤濃度により異なることが確認された．To optimize patient dose in dual-energy computed tomography (DECT), radiation dose and image quality, operating characteristics of automatic exposure control (AEC), and physical and clinical assessment of attenuation values in virtual non-contrast (VNC) images were evaluated. Although DECT provides images which have image quality inferior to single-energy CT (SECT), it can be performed with less radiation dose. The combination of AEC and DECT is unsuitable for obese patients because it tends to provide lower radiation dose and higher image noise levels than the combination of AEC and SECT. Attenuation in VNC images differs depending on the acquisition protocol, patient size, and contrast agent concentration.研究課題/領域番号:24791279, 研究期間(年度):2012-04-01 - 2015-03-31出典：研究課題「Dual-energy CTの被ばく線量解析および多角的線量最適化手法の構築」課題番号24791279
（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/report/KAKENHI-PROJECT-24791279/24791279seika/）を加工して作成金沢大学医薬保健研究域保健学系research repor
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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