1,720,977 research outputs found
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
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
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
Using of Transient Stress Waves for Flaw Dectection in I-shaped Contrete Beams
No full text土木橋樑工程普遍採用預力混凝土I形探作為支承上部結構之用，本
論文旨在對I形樑之敲擊回音反應作一完整分析，以瞭解敲擊回音法偵測
其內部瑕疵方面之適用性。 本論文以AASHTO第一種標準斷面為主要分
析對象，首先，利用三維數值分析對樑之底部進行敲劃試驗，然後利用有
限元素特徵值解法及三維有限元素共振分析法確認這些斷面模態，再將其
結果推廣至其他標準斷面I形樑之應用，並由試驗所得的敲擊反應予以驗
證。 為了達到實際應用敲擊回音法於鋼筋混凝土I形樑品質檢測之目的
，本論文亦針對I形樑內含裂縫及預力套管之試體進行敲擊試驗，結果顯
示內部含有裂縫的I形樑其敲擊回音頻譜將和完整斷面之敲擊反應有很明
顯的差異，而且在頻譜上可找到因裂縫存在而形成反射介面所對應的高振
幅尖峰，以協助確定瑕疵的位置。對於I形樑內預力套管之情況，亦初步
了解其因壓力灌漿不實導致孔隙存在套管內部所造成之影響
Detection of Ungrouted Ducts Using the Impact-Echo Method
No full text在橋樑工程上，常採用預力混凝土箱型節塊或I形樑以增加橋樑跨度，其
中又以後拉法施工最為普遍。本論文之目的，即以敲擊回音法對在施加預
力後，鋼腱套管中填灌水泥漿之施工品質良窳，進行非破壞檢測上之應用
研究。首先，利用數值分析方法，對不同尺寸之套管及其位置之變化，所
產生因敲擊而引起之波動行為的差異，並評估敲擊回音法在套管灌漿品質
檢測上之應用性。根據數值分析之結果，規劃實驗室試體，試體將包含灌
漿完整及不完整之套管，實際進行敲擊試驗，以驗證數值分析結果。數值
及試驗結果顯示，若套管內部是灌漿良好的情況時，其應力波可以穿透填
灌漿，而無反射應力波的訊號出現；但是若套管內部因灌漿不良而形成瑕
疵介面時，不管其瑕疵是完全中空或是部份中空，都會將應力波反射到版
表面，而使敲擊反應頻譜上出現因瑕疪存在所產生之相對應的高振幅尖峰
，用以確定套管內部是否含有瑕疵。Prestressed box girders and I-shaped beams are commonly used in
bridge construction. The objective of this research is to
determine whether the impact-echo method is capable of detecting
voids in grouted post-tensioning tendon ducts. Numerical studies
were performed first to understand how the stress waves produced
by point impact interact with completely or partially grouted
ducts. The feasibility of using the impact-echo method for
detection of voids in ducts can be evaluated. Laboratory studies
were carried out to verify the numerical results. Results
obtained from these studies show that there exists a big
difference between the spectra obtained from impact-echo tests
on completely grouted ducts and those for partially grouted
ducts. The location of the ducts containing voids can be
determined by identifying the corresponding high amplitude peak
in the spectrum
Influence of Reinforcing Bars on Determining the Depths of Surface-Opening Cracks in Concrete
No full text鋼筋混凝土結構常因內在或外在因素造成混凝土結構表面裂縫之產生，
而裂縫之存在則可能使得該結構發生倒塌，或對結構耐久性 產生影響。
因此如何獲得鋼筋混凝土結構之表面開裂深度成為安全評 估工作中極為
重要之一環。 本論文所提之改
良式敲擊回音法先前研究對於一般簡單配筋之鋼筋混凝土樑之裂縫深度檢
測已有相當之成果，且對於單根鋼筋其最 短傳播路徑已能確實掌握，本
論文延伸先前研究之成果，針對更複雜 鋼筋排列之鋼筋混凝土樑做裂縫
深度檢測，除了瞭解其鋼筋訊號變化 之外，並探討其對表面裂縫檢測所
造成之影響。本實驗採全尺寸試 體，並配置不同之鋼筋排列方式，以
直接加載之方式將試體壓壞，使 其產生真實之裂縫，再使用改良式敲擊
回音法加以施測。實驗前並先 對不同之鋼筋排列方式進行數值分析以確
實掌握鋼筋所造成之訊號，並輔以超音波法進行裂縫深度之量測。由實驗
所得之結果顯示， 改變鋼筋號數、變化鋼筋埋置深度或鋼筋排列方式（
並排或雙層）， 其所產生之鋼筋訊號皆不會對應力波經裂縫尖端繞射而
至之波到時間產生判讀上之困難，對表面裂縫深度檢測亦不會造成影響及
誤差。 而超音波法則受限於混凝土之非均質性及鋼筋效應之影響，並無
法得 到良好之結果，因此改良式敲擊回音法對於鋼筋混凝土結構物之裂
縫 深度檢測極具可行性且比超音波法較具優勢。Cracks may occur on the surface of reinforced concrete
structures subjected to external loads as well as
material deterioration. The existence of cracks reduces
significantly structural durability and , furthermore, may lead
to the collapse of structures. Therefore, it is widely recognize
that thedetermination of the depth of surface-opening cracks in
concrete structures is very important. The modified impact-
echo technique has been successfully used to
determine the depth of surface-opening cracks in pure
concrete specimens and in concrete specimens containing single
steel reinforcing bar. In previous studies, the travel
path of stress waves propagating in single steel bar was
determined. The objective of this
research project is to determine the influences on the
crack depth measurement caused by the presence of multiple steel
reinforcing bars with various arrangement. Experimental studies
were carried out on full scale reinforced concrete
beams containing cracks created by applying loads on the
specimens with a 600-ton MTS machine. Experimental
parameters include the size and cover thickness of reinforcing
bars and the arrangement of multiple reinforcing bars.
Experimental results were verified by coring. Numerical
studies were also performed to investigate how the
presence of multiple reinforcing bars affects the stress wave
propagation. Results obtained from the studies show that the
arrival time of the diffracted P-wave is still easy to
identify in the waveform, even though the specimen contains
multiple reinforcing bars. As a result, the presence of
multiple reinforcing bars does not affect the measurement of
the crack depth with the modified impact-echo technique. In
addition, the differences between the measured depths and
the true depths are less than 0.01 m. For comparison, a
conventional ultrasonic testing with a portable digital
apparatus was also used to measure the crack depth. However, the
results obtained from ultrasonic testing are not only unstable
but also unsatisfactory
- …
